freecalypso-docs: FC-handset-spec annotate

annotate FC-handset-spec @ 103:c5f1f936dec5

Install-location: new article

author	Mychaela Falconia <falcon@freecalypso.org>
date	Mon, 20 Nov 2023 08:28:16 +0000
parents	f5b954172002
children

rev	line source
41 7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	1 FreeCalypso Handset Specification
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	2 =================================
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	3
78 a05195c86d3a FC-handset-spec: introduce all 4 chapters Mychaela Falconia <falcon@freecalypso.org> parents: 77 diff changeset	4 The purpose of this document is multifold:
a05195c86d3a FC-handset-spec: introduce all 4 chapters Mychaela Falconia <falcon@freecalypso.org> parents: 77 diff changeset	5
a05195c86d3a FC-handset-spec: introduce all 4 chapters Mychaela Falconia <falcon@freecalypso.org> parents: 77 diff changeset	6 * Chapter 1 gives the principal design specification for the FreeCalypso Libre
a05195c86d3a FC-handset-spec: introduce all 4 chapters Mychaela Falconia <falcon@freecalypso.org> parents: 77 diff changeset	7 Dumbphone handset hardware which I, Mother Mychaela, seek to build as a
a05195c86d3a FC-handset-spec: introduce all 4 chapters Mychaela Falconia <falcon@freecalypso.org> parents: 77 diff changeset	8 distant long-term goal.
41 7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	9
78 a05195c86d3a FC-handset-spec: introduce all 4 chapters Mychaela Falconia <falcon@freecalypso.org> parents: 77 diff changeset	10 * Chapter 2 defines the scope of functionality to be supported in FreeCalypso
a05195c86d3a FC-handset-spec: introduce all 4 chapters Mychaela Falconia <falcon@freecalypso.org> parents: 77 diff changeset	11 handset firmware, including support for additional hardware targets beyond
a05195c86d3a FC-handset-spec: introduce all 4 chapters Mychaela Falconia <falcon@freecalypso.org> parents: 77 diff changeset	12 the primary FC handset hw target.
41 7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	13
78 a05195c86d3a FC-handset-spec: introduce all 4 chapters Mychaela Falconia <falcon@freecalypso.org> parents: 77 diff changeset	14 * Chapter 3 gives the principal design specification for FreeCalypso Venus
a05195c86d3a FC-handset-spec: introduce all 4 chapters Mychaela Falconia <falcon@freecalypso.org> parents: 77 diff changeset	15 development board, which is a more near-term piece of hardware I seek to
a05195c86d3a FC-handset-spec: introduce all 4 chapters Mychaela Falconia <falcon@freecalypso.org> parents: 77 diff changeset	16 build, nearer than the long-term goal of Chapter 1.
a05195c86d3a FC-handset-spec: introduce all 4 chapters Mychaela Falconia <falcon@freecalypso.org> parents: 77 diff changeset	17
a05195c86d3a FC-handset-spec: introduce all 4 chapters Mychaela Falconia <falcon@freecalypso.org> parents: 77 diff changeset	18 * Chapter 4 explains the side project of FreeCalypso Lite aftermarket firmware
a05195c86d3a FC-handset-spec: introduce all 4 chapters Mychaela Falconia <falcon@freecalypso.org> parents: 77 diff changeset	19 on Motorola C139 hardware.
41 7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	20
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	21 1. FC handset hardware specification
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	22
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	23 1.1. Basic features
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	24
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	25 The Mother's goal is to produce a replacement for the proprietary Pirelli DP-L10
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	26 phone, or more specifically, for the GSM-only subset of this Pirelli phone which
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	27 the Mother actually uses, without Pirelli's key differentiating feature of
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	28 non-GSM WiFi operation, and without Pirelli's camera. The following hardware
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	29 features are to be included:
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	30
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	31 * 176x220 pixel color display (no touch)
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	32 * 21-button main keypad
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	33 * 3 side buttons for volume control and an auxiliary function
59 3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	34 * hands-free loudspeaker, also to be used for ringing
42 6b61d77f7700 FC-handset-spec: missed the loudspeaker and vibrator in 1.1 Mychaela Falconia <falcon@freecalypso.org> parents: 41 diff changeset	35 * vibrator
41 7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	36 * USB port that combines charging and computer interface
46 1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	37 * wired analog headset jack
41 7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	38 * single SIM slot
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	39
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	40 The following features which are commonly found in mainstream proprietary
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	41 phones, particularly more recent ones, will NOT be included:
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	42
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	43 * camera
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	44 * Bluetooth
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	45 * FM radio
58 e6a1d1699ebb FC-handset-spec: explicitly list stereo/music exclusion Mychaela Falconia <falcon@freecalypso.org> parents: 57 diff changeset	46 * MP3 or any other music player
e6a1d1699ebb FC-handset-spec: explicitly list stereo/music exclusion Mychaela Falconia <falcon@freecalypso.org> parents: 57 diff changeset	47 * stereo headphone output or any other beyond-voice audio
41 7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	48 * TV receiver
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	49 * GPS receiver
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	50 * dual SIM slot
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	51 * torch light beyond LCD and keypad backlights
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	52
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	53 1.2. RF band capability
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	54
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	55 Our FC handset needs to be quadband GSM; this quadband capability will be
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	56 achieved by copying the RF section and the core PCB layout around it from the
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	57 reverse-engineered iWOW TR-800 modem module, which is itself a very direct
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	58 (almost verbatim) derivative of TI's Leonardo+ quadband reference design.
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	59
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	60 1.3. RAM and flash
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	61
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	62 The Mother's intent is to use Spansion S71PL064JA0 flash+RAM MCP on the final
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	63 handset motherboard, providing 8 MiB of flash and 2 MiB of XRAM in a 7x9 mm
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	64 footprint. This flash and RAM capacity is already known to be fully sufficient
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	65 for our FreeCalypso handset firmware in maximal feature configuration, hence
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	66 any larger capacity would be excessive. However, on our FC Venus development
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	67 board we may use the larger S71PL129NC0 MCP, same as used on FCDEV3B V2.
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	68
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	69 1.4. Liquid crystal display
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	70
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	71 1.4.1. Display size
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	72
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	73 The size of the display for our FC Libre Dumbphone handset design is fixed at
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	74 176x220 pixels, 16-bit color, following TI's D-Sample platform and the starting
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	75 point UI code that was developed for it. Thoughts of changing to a different
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	76 display size have been considered and rejected:
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	77
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	78 * If we were to change to a smaller display size, we would have to do extra work
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	79 on the firmware to shrink the UI to the smaller size, and we would reduce the
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	80 amount of information that can be displayed at once. We would incur extra
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	81 work and a functional loss, but gain absolutely nothing in return.
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	82
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	83 * If we were to change to a larger display size (240x320 pixels seems to be the
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	84 largest reasonable size for dumbphones, used in high-end Nokia models), we
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	85 would be venturing into uncertain territory - the greatest uncertainty would
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	86 be the extra CPU load on Calypso to draw the larger UI and to refresh the
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	87 larger framebuffer, which is done with PIO on Calypso, without any DMA
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	88 assistance. The D-Sample LCD size of 176x220 pixels already appears to be a
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	89 strain in some drawing code paths, hence the Mother's decision is to play it
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	90 safe and stick with the known working display size. Expanding the UI to make
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	91 sensible use of larger screen real estate would also entail additional work.
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	92
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	93 176x220 is the display size in pixels, and this resolution number by itself says
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	94 nothing about the physical display size in inches or mm. However, most readily
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	95 available LCDs that are made for this pixel resolution are made in 2.0" diagonal
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	96 physical size, with 31.68x39.60 mm active area and 0.180 mm dot pitch, hence
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	97 this physical size is the one we are going to use.
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	98
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	99 1.4.2. Specific LCD module selection
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	100
73 eb68975e1b81 FC-handset-spec: KWH020ST23-F01 finalized Mychaela Falconia <falcon@freecalypso.org> parents: 69 diff changeset	101 Over the summer of 2021 we have selected Formike KWH020ST23-F01 as our LCD
eb68975e1b81 FC-handset-spec: KWH020ST23-F01 finalized Mychaela Falconia <falcon@freecalypso.org> parents: 69 diff changeset	102 module for FreeCalypso; in prior years we had evaluated two other LCD modules
eb68975e1b81 FC-handset-spec: KWH020ST23-F01 finalized Mychaela Falconia <falcon@freecalypso.org> parents: 69 diff changeset	103 from HaoRan and Startek. All relevant datasheets (our finally chosen LCD
eb68975e1b81 FC-handset-spec: KWH020ST23-F01 finalized Mychaela Falconia <falcon@freecalypso.org> parents: 69 diff changeset	104 module, our previous candidate LCD modules and the controller ICs inside these
eb68975e1b81 FC-handset-spec: KWH020ST23-F01 finalized Mychaela Falconia <falcon@freecalypso.org> parents: 69 diff changeset	105 modules) are collected here:
eb68975e1b81 FC-handset-spec: KWH020ST23-F01 finalized Mychaela Falconia <falcon@freecalypso.org> parents: 69 diff changeset	106
eb68975e1b81 FC-handset-spec: KWH020ST23-F01 finalized Mychaela Falconia <falcon@freecalypso.org> parents: 69 diff changeset	107 ftp://ftp.freecalypso.org/pub/embedded/LCDs/
eb68975e1b81 FC-handset-spec: KWH020ST23-F01 finalized Mychaela Falconia <falcon@freecalypso.org> parents: 69 diff changeset	108
eb68975e1b81 FC-handset-spec: KWH020ST23-F01 finalized Mychaela Falconia <falcon@freecalypso.org> parents: 69 diff changeset	109 Our LCD module selection criteria were as follows:
41 7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	110
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	111 * TFT color LCD, 2.0" diagonal, 176x220 pixel resolution;
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	112
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	113 * 16-bit microprocessor bus interface;
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	114
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	115 * 6:00 viewing direction as appropriate for cellular handsets;
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	116
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	117 * backlight consisting of 3 white LEDs in parallel, joined at the anode,
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	118 with separately brought-out cathodes;
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	119
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	120 * mechanical design that supports mounting with the FPC tail folded under the
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	121 module, either by way of direct solder termination (no connector) or by way
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	122 of raised sides that create sufficient vertical space to accommodate the FPC
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	123 connector.
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	124
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	125 The requirement of 16-bit microprocessor bus interface stems from the desire to
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	126 interface this LCD to the Calypso in exactly the same way how TI did it on the
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	127 D-Sample, the 6:00 viewing direction and mechanical mounting requirements stem
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	128 naturally from the target application (cellular phone handset), and the
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	129 backlight LED wiring requirement stems from the constraints of our chosen
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	130 MAX1916 backlight LED driver chip - see section 1.4.4.
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	131
67 ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	132 Formike KWH020ST23-F01 is an LCD module that was discovered by Mother Mychaela
73 eb68975e1b81 FC-handset-spec: KWH020ST23-F01 finalized Mychaela Falconia <falcon@freecalypso.org> parents: 69 diff changeset	133 in May-June of 2021, and it satisfies all of our requirements. In June of 2021
eb68975e1b81 FC-handset-spec: KWH020ST23-F01 finalized Mychaela Falconia <falcon@freecalypso.org> parents: 69 diff changeset	134 we received sample pieces, then we designed a test board for the purpose of
eb68975e1b81 FC-handset-spec: KWH020ST23-F01 finalized Mychaela Falconia <falcon@freecalypso.org> parents: 69 diff changeset	135 evaluating this new LCD, connecting it to our Luna interface from 2020. Our
82 e279a924f7a3 FC-handset-spec: update for Formike LCD modules being here Mychaela Falconia <falcon@freecalypso.org> parents: 81 diff changeset	136 lunalcd2 test board was finally assembled in August, all tests passed, and in
e279a924f7a3 FC-handset-spec: update for Formike LCD modules being here Mychaela Falconia <falcon@freecalypso.org> parents: 81 diff changeset	137 September of 2021 we have bought 100 pcs of this finally chosen LCD module.
e279a924f7a3 FC-handset-spec: update for Formike LCD modules being here Mychaela Falconia <falcon@freecalypso.org> parents: 81 diff changeset	138 This stash of 100 LCD modules is expected to be sufficient as a lifetime buy.
67 ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	139
41 7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	140 1.4.3. Backlight and readability considerations
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	141
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	142 Out of the various pre-existing mobile phones which I (Mychaela) have
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	143 experienced, there have been 3 different kinds of LCDs in terms of how display
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	144 operation and readability interacts with the backlight:
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	145
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	146 1) older phones with black&white LCDs: on all phones of this type which I've
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	147 ever used, the display is perfectly readable without the backlight given
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	148 ordinary ambient lighting, be it natural daylight or room lighting. Such
54 138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	149 LCDs are called transflective: primarily reflective, but can also operate in
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	150 transmissive mode when the optional backlight is turned on. With these B&W
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	151 displays, you only need to turn on the backlight if you need to operate the
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	152 phone in darkness, such as outdoors at night or inside with all lights off.
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	153 The firmware in such phones is typically designed to leave the actual display
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	154 functional and updated at all times, with only the backlight subject to
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	155 on/off control.
41 7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	156
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	157 2) most newer phones with color displays, of which Pirelli DP-L10 is a
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	158 representative case, have transmissive LCDs that are not designed to be
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	159 readable without the backlight at all - backlight required for readability
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	160 (BLRR) is another way to describe such LCDs. Because the display is not
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	161 readable at all without the backlight, phone firmware is typically designed
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	162 to turn off the entire display (not just the backlight) when the screen goes
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	163 dark, and operation visible to the user is display on/off, rather than
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	164 backlight on/off. It is a good firmware design practice to "swallow" the
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	165 initial keypress that turns on the display from dark state, i.e., to block
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	166 the regular action of whatever button was pressed to "wake up" the display.
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	167
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	168 3) The color display on Motorola C139 phones is an odd intermediate case: this
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	169 display is NOT practically readable with the backlight off, yet the firmware
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	170 is designed as if the display were readable in this condition: the actual
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	171 display (unsure if it is CSTN or TFT) remains on and updated, and when you
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	172 press some button to "wake up" the display, that button still takes its
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	173 regular action, which is really bad for usability. How do we know that the
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	174 actual CSTN or TFT display remains on and actively updated when it is not
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	175 readable with the backlight off? Answer: the non-backlit display can be made
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	176 readable by shining a flashlight directly at it - but this trick requires a
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	177 directly pointed flashlight; no amount of ordinary ambient light is enough
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	178 to make the display readable.
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	179
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	180 Because our FC Libre Dumbphone handset will have a color display (contemporary
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	181 TFT) and because we are sane, not copying the monumental design mistake of Mot
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	182 C139, our display will fall into class 2 by the above classification: backlight
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	183 required for readability, full display on/off rather than just backlight on/off,
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	184 firmware operating like Pirelli's in terms of wake-up keypress swallowing.
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	185
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	186 1.4.3.1. Backlight dimming mode
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	187
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	188 Because our LCD is of BLRR type and because we seek to fully replicate Pirelli's
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	189 logic in terms of when keypresses are swallowed and when they are not, we need
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	190 to implement a dimming mode for our LCD backlight. In Pirelli's design which we
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	191 are copying, when you are playing with phone menus or composing SMS etc, but are
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	192 not in an active call, the display switches between full brightness and totally
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	193 off - it goes fully off on timeout, and when you press a button to wake it up,
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	194 it switches on at full brightness, together with the keypad backlight. But when
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	195 you are in a call, when the timer expires (and it's a shorter timer, 10 s
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	196 instead of 30 s), the display goes dim instead of fully off, and in this dimmed
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	197 (but still readable) state keypresses are NOT swallowed.
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	198
67 ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	199 In terms of absolute requirements, we only need to implement two different
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	200 intensity levels for the LCD backlight: full brightness and in-call dimmed.
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	201 The backlight intensity level in the dimmed state will need to be chosen on
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	202 this principle: use the lowest backlight LED current (to conserve battery power
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	203 and allow longest talk time on one charge) at which the display is still
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	204 readable, similarly to Pirelli's in-call dimmed state. In the user-actively-
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	205 poking state, as opposed to the long-call dimmed state, there is no strict need
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	206 to provide different configurable backlight levels - but it so happens that our
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	207 implementation will allow a total of 4 different backlight intensity levels -
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	208 see section 1.4.4.1.
41 7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	209
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	210 1.4.4. Backlight circuit implementation
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	211
73 eb68975e1b81 FC-handset-spec: KWH020ST23-F01 finalized Mychaela Falconia <falcon@freecalypso.org> parents: 69 diff changeset	212 In all candidate TFT LCD modules that have been considered (see section 1.4.2),
41 7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	213 the backlight consists of 3 white LEDs wired in parallel, joined either at the
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	214 anode or at the cathode - although as we shall see momentarily, we require an
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	215 LCD module where the 3 LEDs are joined at the anode, with the 3 cathodes brought
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	216 out separately. LCD module datasheets call for 15 mA current through each LED
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	217 at maximum intensity, for 45 mA total, and the LED forward drop voltage (Vf) at
74 e4eebf9ffce3 FC-handset-spec: Vf=2.9 V on both HaoRan and Formike LCD modules Mychaela Falconia <falcon@freecalypso.org> parents: 73 diff changeset	218 this rated current seems to range between 2.9 V (what I actually measured on
e4eebf9ffce3 FC-handset-spec: Vf=2.9 V on both HaoRan and Formike LCD modules Mychaela Falconia <falcon@freecalypso.org> parents: 73 diff changeset	219 both Formike and HaoRan LCD modules) to 3.2 V (what the datasheets list as
e4eebf9ffce3 FC-handset-spec: Vf=2.9 V on both HaoRan and Formike LCD modules Mychaela Falconia <falcon@freecalypso.org> parents: 73 diff changeset	220 typical) to perhaps as high as 3.4 V (what one datasheet lists as the maximum).
41 7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	221
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	222 Given the parallel (as opposed to series) wiring of the 3 LEDs and the
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	223 relatively low Vf, there is no need to use any kind of boost converter as part
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	224 of the LED driver circuit for this backlight - any boost converter will only add
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	225 inefficiency (more current will be drawn from the battery for the same LED
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	226 current), hence we need to avoid using such.
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	227
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	228 Regardless of whether a given phone design uses a boost converter or not (it
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	229 seems that older designs do use boost converters, either because older white
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	230 LEDs have higher Vf or because 2 or 3 LEDs are wired in series), all traditional
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	231 phone designs seem to share the quality where the display backlight brightness
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	232 remains the same as the battery discharges and as Vbat goes down - this quality
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	233 was directly observed on the Pirelli DP-L10 (unknown circuit design) and
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	234 inferred from the available schematics for Mot C139 and C155, with both of the
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	235 latter boost-converting to fixed 5.0 V. In our case, even though we choose to
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	236 not use a boost converter for efficiency reasons, we still need to achieve the
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	237 quality of the display brightness remaining the same through the discharge range
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	238 of our Li-ion battery - having the display dim in half as the battery discharges
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	239 from 4.2 V peak to 3.6-3.7 V plateau is simply not acceptable.
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	240
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	241 The simplest possible LED driving circuit would be one where a current limiting
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	242 resistor is inserted in series with each LED, and then the 3 parallel
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	243 LED+resistor sets are connected across battery terminals, with a transistor
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	244 inserted somewhere to act as the on/off switch. However, this trivial circuit
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	245 is not suitable in our application because it would produce unacceptably large
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	246 variation in display brightness as the battery discharges - hence we need a more
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	247 intelligent LED driving circuit. Our Luna LCD carrier board from the spring of
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	248 2020 features an LDO bringing Vbat down to fixed 3.5 V, followed by very low-
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	249 value resistors in series with each LED - but this approach is not good for
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	250 production either, as it makes the LED current extremely sensitive to any slight
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	251 variations in Vf.
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	252
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	253 Fortunately, I was able to find a specialized white LED driver chip that is just
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	254 perfect for our application, or more precisely, a specialized chip that acts as
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	255 a constant current sink for such LEDs - Maxim MAX1916, design from 2001, just
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	256 the right time frame for the kind of phone we are seeking to build. This
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	257 special chip takes the place of "dumb" ballast resistors: connect Vbat (battery
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	258 positive terminal) directly to the common anode of the 3 LEDs, but instead of
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	259 series resistors, connect each cathode to the corresponding LEDn pin of MAX1916
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	260 - without any resistors or transistors! FETs inside the MAX1916 take the
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	261 place of resistors as current-limiting elements, and the chip's global on/off
44 a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	262 control (which will be driven with a Calypso GPIO) takes the place of a separate
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	263 switching transistor.
41 7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	264
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	265 The special quality of MAX1916 is that it produces constant current through each
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	266 LED (based on a set reference current and 230x current multiplication circuit
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	267 inside the chip) regardless of variations in both Vbat and Vf! Of course the
67 ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	268 requested current can only be sustained as long as Vbat >= Vf + Vds_min, where
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	269 Vds_min is the lowest drop voltage of the FETs inside MAX1916, and once Vbat
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	270 falls below this point, the LED current will begin to decline. However, the
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	271 beauty of this design is that no arbitrary artificial turnover points (like the
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	272 3.5 V point in our hacky design from the spring of 2020) need to be set: the
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	273 battery discharge point at which the LED current begins to decline will be
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	274 whatever it comes to be naturally, based on Vf (perhaps depending on
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	275 temperature) and MAX1916 Vds_min, and the decline is expected to be gradual.
41 7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	276
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	277 1.4.4.1. Backlight current selection and dimming
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	278
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	279 In the simplest MAX1916-based design, a fixed LED current is set by connecting
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	280 a resistor of appropriately computed value between MAX1916 SET pin and whatever
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	281 regulated fixed voltage rail happens to be available in the system. However,
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	282 in our application (see section 1.4.3.1) we need at least two different display
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	283 brightness levels, and thus at least two switchable LED currents. At first the
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	284 problem seems difficult, but an elegant solution has been found.
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	285
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	286 LCD backlight LED current will be selected by way of two Calypso GPIO pins
92 f5b954172002 FC-handset-spec: document the use of 74LVC2G126 Mychaela Falconia <falcon@freecalypso.org> parents: 90 diff changeset	287 configured as outputs, and a 74LVC2G126 dual tristate buffer. Each tristate
41 7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	288 buffer's A input will be tied high, and the two Calypso GPIO outputs will be
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	289 connected to buffer output enable inputs. There will be two resistors with
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	290 different carefully computed values, each connected between one of the two
67 ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	291 tristate buffer outputs and MAX1916 SET pin. There will also be a third
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	292 resistor connected between MAX1916 SET pin and the V-IO rail.
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	293
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	294 The values of the 3 just-described resistors will be selected so that the path
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	295 through each SET resistor will add a different contribution to the total LED
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	296 current. The always-on SET resistor will provide the smallest current
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	297 corresponding to the long-call dimmed mode, whereas the sum of all 3
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	298 contribution currents will equal the 15 mA limit - the current is reckoned per
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	299 LED. The difference between the 15 mA maximum and the small dimmed mode current
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	300 will be split unequally between the two switched SET resistors, allowing a total
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	301 of 4 different backlight intensity levels to be selected via the two Calypso
92 f5b954172002 FC-handset-spec: document the use of 74LVC2G126 Mychaela Falconia <falcon@freecalypso.org> parents: 90 diff changeset	302 GPIO outputs going to the 74LVC2G126 buffer's output enable inputs. The actual
73 eb68975e1b81 FC-handset-spec: KWH020ST23-F01 finalized Mychaela Falconia <falcon@freecalypso.org> parents: 69 diff changeset	303 currents will be determined after some further experimentation with our lunalcd2
eb68975e1b81 FC-handset-spec: KWH020ST23-F01 finalized Mychaela Falconia <falcon@freecalypso.org> parents: 69 diff changeset	304 test setup: this setup features our KWH020ST23-F01 LCD, a MAX1916-based
eb68975e1b81 FC-handset-spec: KWH020ST23-F01 finalized Mychaela Falconia <falcon@freecalypso.org> parents: 69 diff changeset	305 backlight circuit, and a DIP switch pack selecting the LED current in 1 mA
eb68975e1b81 FC-handset-spec: KWH020ST23-F01 finalized Mychaela Falconia <falcon@freecalypso.org> parents: 69 diff changeset	306 increments.
41 7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	307
92 f5b954172002 FC-handset-spec: document the use of 74LVC2G126 Mychaela Falconia <falcon@freecalypso.org> parents: 90 diff changeset	308 74LVC2G126 has been chosen as the dual tristate buffer part instead of more
f5b954172002 FC-handset-spec: document the use of 74LVC2G126 Mychaela Falconia <falcon@freecalypso.org> parents: 90 diff changeset	309 common 74LVC2G125 because the '126 has active-high output enable inputs, making
f5b954172002 FC-handset-spec: document the use of 74LVC2G126 Mychaela Falconia <falcon@freecalypso.org> parents: 90 diff changeset	310 the software interface (bits in the GPIO output register) more intuitive: with
f5b954172002 FC-handset-spec: document the use of 74LVC2G126 Mychaela Falconia <falcon@freecalypso.org> parents: 90 diff changeset	311 a '126 buffer, writing 1 into GPIO11 or GPIO12 will turn on the corresponding
f5b954172002 FC-handset-spec: document the use of 74LVC2G126 Mychaela Falconia <falcon@freecalypso.org> parents: 90 diff changeset	312 current contribution, whereas a '125 buffer would produce an inverted sense.
f5b954172002 FC-handset-spec: document the use of 74LVC2G126 Mychaela Falconia <falcon@freecalypso.org> parents: 90 diff changeset	313 74LVC2G126GT parts were less readily available than the '125 counterpart, but
f5b954172002 FC-handset-spec: document the use of 74LVC2G126 Mychaela Falconia <falcon@freecalypso.org> parents: 90 diff changeset	314 we have now made a lifetime buy of the preferred part.
f5b954172002 FC-handset-spec: document the use of 74LVC2G126 Mychaela Falconia <falcon@freecalypso.org> parents: 90 diff changeset	315
41 7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	316 1.4.5. Slight regression relative to Pirelli DP-L10
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	317
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	318 The actual LCD backlight LED driving circuit inside the Pirelli phone is not
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	319 known, but reverse engineering of Pirelli's firmware followed by experimentation
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	320 reveals that backlight intensity variation is achieved via a form of PWM, using
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	321 Calypso PWL output - although PWL is used in an inverted sense, such that the
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	322 backlight intensity increases with more 0s being put out on PWL, as opposed to
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	323 more 1s. Thus regardless of the unknown actual circuit implementation, the
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	324 backlight intensity appears to be continuously variable from 1/255 to 255/255,
67 ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	325 which is certainly a much richer control than our crude selection of just 4
41 7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	326 possible LED currents.
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	327
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	328 In terms of what Pirelli's fw offers to end users, the backlight intensity in
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	329 the dimmed in-call state is always set to 1/255, without any way to change it,
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	330 whereas the backlight intensity in the active interaction state is selectable
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	331 via a menu among 5 levels; the 5 offered levels turn into 1/255, 64/255,
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	332 128/255, 192/255 and 255/255 in the resulting PWL programming.
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	333
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	334 So in terms of both hardware capabilities and end user offering via the
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	335 firmware, Pirelli's LCD backlight level control is richer than what we are
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	336 proposing for our FC Libre Dumbphone. However, engineering is all about
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	337 trade-offs and compromises, and in the Mother's opinion, this slight reduction
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	338 in the richness of functionality is sufficiently offset by the efficiency of
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	339 our MAX1916-based approach: aside from the theoretical possibility of a
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	340 switching buck converter, which I've never seen used for LED driving
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	341 applications, our choice of MAX1916 is the most battery-efficient way to drive
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	342 our backlight LEDs. Furthermore, when dimming is effected by switching the
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	343 actual regulated LED current, as in our case, as opposed to applying PWM, our
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	344 backlight becomes more resilient to even lower battery voltages.
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	345
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	346 Consider what happens when Vbat falls below the point at which the design-
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	347 intended LED current can be maintained - what happens then? If no PWM is
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	348 applied, or if PWM is set to maximum, then display brightness will be whatever
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	349 maximum is possible at this low battery voltage. But if PWM is applied,
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	350 especially very low duty cycles as in the case of Pirelli's dimmed state, then
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	351 the display that has already been dimmed by low Vbat will be further dimmed
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	352 by this aggressive PWM, likely producing an unreadable display at this point.
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	353 It may be possible to compensate via extra complexity in the firmware, by
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	354 turning PWM up when Vbat (as measured via Iota MADC) falls too low - but then
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	355 we would be getting really messy, whereas switching the regulated current is so
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	356 much more elegant. With our approach, low-battery-induced dimming in the "full
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	357 brightness" mode will happen at the same discharge point as it would if we had
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	358 used PWM (and set PWM to maximum in this "full brightness" mode), but in the
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	359 in-call dimmed state, further dimming due to low Vbat will probably happen at a
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	360 lower discharge point (if Vf decreases with decreasing current), and when it
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	361 does happen, there won't be a combination of both natural and artificially-
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	362 induced reductions, just the natural one.
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	363
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	364 Thus based on all of the above considerations, I feel justified in my design
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	365 choice of foregoing PWM control of backlight intensity in favor of fixed current
7d77aa76bcaa FC-handset-spec: beginning of massive document Mychaela Falconia <falcon@freecalypso.org> parents: diff changeset	366 switching with much more limited selection.
44 a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	367
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	368 1.5. Main keypad
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	369
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	370 The main keypad on our FC Libre Dumbphone handset will have the following
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	371 21-button arrangement:
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	372
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	373 left soft key ^ right soft key
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	374 <O>
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	375 green call V red power/hang-up
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	376 button button
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	377
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	378 1 2 3
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	379 4 5 6
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	380 7 8 9
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	381 * 0 #
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	382
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	383 The top section above the traditional numeric dial buttons (12) consists of left
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	384 and right soft keys, green and red buttons (classically called SEND/END), and a
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	385 5-way navigation button group (left, right, up, down and center), for a total of
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	386 9 buttons in this section. The red hang-up button is also the hardware power-on
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	387 button; having the same button effect power-off when held down for some time is
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	388 a firmware function.
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	389
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	390 This 21-button main keypad arrangement is exactly the same as featured on
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	391 Motorola C1xx and Pirelli DP-L10 phones, on TI's D-Sample development platform,
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	392 and also on many other phones (non-Calypso) from the appropriate era, such as
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	393 Samsung E2232.
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	394
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	395 1.5.1. Keypad backlight
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	396
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	397 All traditional phones including Mot C1xx and Pirelli DP-L10 feature keypad
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	398 backlights, hence we need to include one as well. The exact structure of this
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	399 backlight won't be known until we enter the mechanical design phase for the
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	400 actual handset (as opposed to intermediate development boards), which will be
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	401 much later in the project, but the Mother's understanding is that keypad
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	402 backlights are made up of some number of LEDs (2 on Pirelli DP-L10, unknown
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	403 number on Mot C139) and some kind of light diffuser.
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	404
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	405 Given the discovery of MAX1916 constant-current-sink LED driver chip (see
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	406 section 1.4.4), the optimal electrical design of the keypad backlight becomes
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	407 clear: use 3 LEDs, and drive them using another MAX1916 chip, separate from the
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	408 one used for the LCD backlight.
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	409
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	410 Backlight intensity: neither Mot C139 nor Pirelli DP-L10 provides any way to
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	411 vary keypad backlight intensity, and no such variability is deemed necessary.
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	412 In the long-call state when the LCD backlight is dimmed, the keypad backlight
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	413 is fully off. We shall use a fixed LED current setting for our keypad
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	414 backlight, set with a single fixed resistor between the keypad MAX1916 chip's
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	415 SET pin and the V-IO rail, and the actual current value will be determined in a
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	416 much later phase of the project, when we have the actual keypad backlight LEDs
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	417 and a better idea of the mechanical design.
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	418
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	419 Backlight color: Mot C139 uses blue LEDs, Pirelli DP-L10 uses white LEDs.
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	420 Because blue and white LEDs have very similar electrical characteristics
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	421 (current needed for appropriate brightness, Vf at this current), the choice
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	422 between the two can be made in a much later project phase, based on input from
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	423 other team members who are better at aesthetics.
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	424
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	425 1.5.1.1. Comparison with Mot C139 and Pirelli DP-L10
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	426
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	427 Both of these two pre-existing reference phones feature keypad backlights that
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	428 are switched on/off via Iota LEDB; the actual circuit design is unknown.
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	429 However, in our design we forego Iota LEDB altogether (it won't be used for
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	430 anything), and use two MAX1916 chips for our LCD and keypad backlights, with
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	431 each chip's on/off control being a Calypso GPIO.
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	432
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	433 The actual workings of the LEDB driver or switch inside the Iota chip are a
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	434 mystery. On the one hand it appears to be nothing more than a "dumb" transistor
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	435 on/off switch, no different from an external "digital transistor" (BJT with bias
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	436 resistors) controlled by a Calypso GPIO: a resistor still seems to be required
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	437 for current control, and at least on the Pirelli DP-L10 the keypad backlight
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	438 intensity visibly varies with Vbat ranging over the Li-ion discharge range. But
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	439 on the other hand, LEDB requires the 13 MHz clock to be running, and the light
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	440 goes out when this clock is stopped. Why in the world would any kind of clock
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	441 be required if the circuit is only a transistor on/off switch controlled by a
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	442 static register bit? Other parts of TI's Iota datasheet describe its LEDA, LEDB
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	443 and LEDC as "current drivers" - but in the absence of any way to actually set
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	444 the desired current without depending on Vbat or Vf variations, whatever the
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	445 Iota chip actually provides can't be anything like MAX1916.
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	446
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	447 Poorly documented, non-understood mystery hardware is best avoided, hence we are
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	448 not going to use Iota LEDB, and shall only use MAX1916 instead. We also gain a
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	449 functional improvement over Pirelli DP-L10 by using MAX1916: our keypad
a415ae467c6d FC-handset-spec: main keypad and its backlight documented Mychaela Falconia <falcon@freecalypso.org> parents: 43 diff changeset	450 backlight intensity will remain the same over the battery discharge range.
45 9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	451
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	452 1.6. Side buttons
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	453
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	454 In addition to the 21-button main keypad, our FC Libre Dumbphone handset will
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	455 include 3 side buttons: two on the left side, intended for volume up/down
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	456 control, and one on the right side, serving auxiliary functions. This side
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	457 button arrangement is identical to TI's D-Sample and similar to Pirelli DP-L10:
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	458 the only difference between our arrangement (matching D-Sample) and Pirelli's
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	459 is that Pirelli moved the 3rd side button to the left and designated it as the
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	460 camera button. However, we (FreeCalypso) have no interest in ever implementing
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	461 any kind of camera on our phones, hence we are moving the 3rd side button back
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	462 to where it was in TI's original design (on the right), and we will use it for
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	463 purposes of our own invention.
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	464
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	465 The starting point UI code we got from TI does not do anything with the right
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	466 side button (even though this button exists and works on the D-Sample platform
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	467 on which this code was originally developed), hence we have full freedom to
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	468 invent our own uses for it. The following uses are envisioned:
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	469
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	470 * Long press of this button may be our way of turning the hands-free loudspeaker
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	471 on and off, a function that does not exist in the starting point UI code from
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	472 TI.
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	473
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	474 * When the phone is in its normal idle standby operation (not in a call and not
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	475 being poked at by the user, but registered to a GSM network and ready to
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	476 accept incoming calls or SMS), the display will be off. Users often desire
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	477 to check the time and other status (check coverage, see if they missed any
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	478 calls or SMS), which will require pressing any button to turn on the display.
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	479 At that point a 30 s timer kicks in, which will turn the display back off
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	480 after 30 s of inactivity. However, an argument can be made that keeping the
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	481 display on for 30 s if the user only wanted to quickly glance at the time is
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	482 a waste of battery. Here is one proposed solution: we can implement a
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	483 function where a short press of the right side button when the phone is on its
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	484 idle screen will cause the display to turn off immediately and activate the
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	485 keyguard. The user can then press the right side button once to turn on the
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	486 display and look at it, and then press the same button again to turn it back
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	487 off.
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	488
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	489 * When we are in a long call, the LCD backlight does not turn off completely,
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	490 instead it will go dim - but still readable. Any button presses in this state
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	491 are NOT swallowed - they take their regular actions. However, the keypad
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	492 backlight turns off fully in this state, and under certain conditions (like
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	493 out at night) the user may not be able to see the keypad. If a short press
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	494 of the right side button invokes no other action besides switching on full
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	495 display brightness and the keypad backlight, this right side button can be
9df8683daec4 FC-handset-spec: side buttons documented Mychaela Falconia <falcon@freecalypso.org> parents: 44 diff changeset	496 found by touch, and thus solve this particular problem case.
46 1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	497
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	498 1.7. Audio routing
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	499
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	500 3 different audio routing modes will be supported on our FC Libre Dumbphone
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	501 handset:
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	502
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	503 * Default mode: there will be a 32 ohm earpiece speaker physically mounted in
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	504 the usual place, on the front bezel above the display, to match up with the
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	505 user's ear in handheld operation. There will also be a microphone toward the
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	506 front bottom of the phone, again in the usual place.
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	507
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	508 * Hands-free mode: there will be an 8 ohm loudspeaker physically separate from
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	509 the 32 ohm earpiece speaker, physical location in the handset TBD. In the
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	510 hands-free mode, the downlink audio will be switched from the earpiece speaker
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	511 to the loudspeaker, while the microphone input for the uplink will remain the
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	512 same.
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	513
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	514 * There will be a wired analog headset jack with plug insertion detection; when
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	515 a headset is inserted, both audio input and output will be redirected to this
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	516 headset interface.
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	517
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	518 1.7.1. Earpiece and loudspeaker separation
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	519
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	520 Most current mainstream phones (in fact, all that I am familiar with) have
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	521 physically separate speaker transducers for the earpiece function (hold up to
64 6b02de926277 FC-handset-spec section 1.7.1: mention Pirelli DP-L10 Mychaela Falconia <falcon@freecalypso.org> parents: 63 diff changeset	522 ear to talk) and the loudspeaker+ringer function. The not-so-current and not-
6b02de926277 FC-handset-spec section 1.7.1: mention Pirelli DP-L10 Mychaela Falconia <falcon@freecalypso.org> parents: 63 diff changeset	523 so-mainstream Pirelli DP-L10 also features the same arrangement. The earpiece
6b02de926277 FC-handset-spec section 1.7.1: mention Pirelli DP-L10 Mychaela Falconia <falcon@freecalypso.org> parents: 63 diff changeset	524 speaker is a 32 ohm load, and the loudspeaker is an 8 ohm load. In a
6b02de926277 FC-handset-spec section 1.7.1: mention Pirelli DP-L10 Mychaela Falconia <falcon@freecalypso.org> parents: 63 diff changeset	525 Calypso+Iota design, an external amplifier chip is needed to drive the 8 ohm
6b02de926277 FC-handset-spec section 1.7.1: mention Pirelli DP-L10 Mychaela Falconia <falcon@freecalypso.org> parents: 63 diff changeset	526 loudspeaker, whereas the little 32 ohm earpiece speaker can be driven directly
6b02de926277 FC-handset-spec section 1.7.1: mention Pirelli DP-L10 Mychaela Falconia <falcon@freecalypso.org> parents: 63 diff changeset	527 by Iota EAR output.
46 1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	528
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	529 However, a very different design was implemented by TI on their D-Sample and
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	530 Leonardo boards. They have only one speaker, one of 8 ohm kind, that is
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	531 physically mounted in the position where the earpiece speaker would normally go.
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	532 In order to not overwhelm the user's ear in handheld operation, they have
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	533 peculiar circuit wiring where the analog signal from Iota to the loudspeaker
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	534 amplifier goes through different resistor values depending on whether EAR or AUX
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	535 output from Iota is used, and when the EAR output is selected, the high resistor
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	536 values produce attenuation, such that the sound pressure level produced by the
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	537 pressed-to-ear loudspeaker becomes comparable to that produced by a more
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	538 traditional 32 ohm earpiece speaker.
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	539
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	540 Furthermore, TI's single speaker design was not limited to their development
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	541 boards. Some years ago I found schematics for some very old LG phone (called
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	542 A316 or B1200, not sure of the correct designation), this phone is from early
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	543 TI era (pre-Calypso, using Ulysse/Nausica/Clara chipset), and it has the same
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	544 arrangement as D-Sample and Leonardo.
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	545
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	546 For our own FC Libre Dumbphone, I am going with the separate speakers
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	547 architecture, using physically separate earpiece and loudspeaker transducers.
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	548 This architecture feels more native to me, and it will allow for independent
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	549 tuning of the two audio paths. In my defense, all current mainstream phones
64 6b02de926277 FC-handset-spec section 1.7.1: mention Pirelli DP-L10 Mychaela Falconia <falcon@freecalypso.org> parents: 63 diff changeset	550 seem to use the same architecture, and so does the Pirelli phone that serves as
6b02de926277 FC-handset-spec section 1.7.1: mention Pirelli DP-L10 Mychaela Falconia <falcon@freecalypso.org> parents: 63 diff changeset	551 my personal reference - the other approach with a single loudspeaker in the
6b02de926277 FC-handset-spec section 1.7.1: mention Pirelli DP-L10 Mychaela Falconia <falcon@freecalypso.org> parents: 63 diff changeset	552 earpiece physical position seems very uncommon.
46 1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	553
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	554 1.7.2. Loudspeaker implementation
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	555
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	556 The external amplifier chip for driving the 8 ohm loudspeaker will be TI
65 153b517ccc7a FC-handset-spec section 1.7.2: make contrast with MIDI ringtone chips Mychaela Falconia <falcon@freecalypso.org> parents: 64 diff changeset	557 TPA6203A1, copied from Leonardo schematics and proven good on FCDEV3B. It is a
153b517ccc7a FC-handset-spec section 1.7.2: make contrast with MIDI ringtone chips Mychaela Falconia <falcon@freecalypso.org> parents: 64 diff changeset	558 "dumb" loudspeaker amplifier, as opposed to a much more complex chip that
153b517ccc7a FC-handset-spec section 1.7.2: make contrast with MIDI ringtone chips Mychaela Falconia <falcon@freecalypso.org> parents: 64 diff changeset	559 combines the loudspeaker amplifier function with a MIDI ringtone player - see
153b517ccc7a FC-handset-spec section 1.7.2: make contrast with MIDI ringtone chips Mychaela Falconia <falcon@freecalypso.org> parents: 64 diff changeset	560 section 1.8. On FCDEV3B this amplifier is fed with signal from Iota EAR output,
153b517ccc7a FC-handset-spec section 1.7.2: make contrast with MIDI ringtone chips Mychaela Falconia <falcon@freecalypso.org> parents: 64 diff changeset	561 but on the final handset and on the Venus development board this amplifier will
153b517ccc7a FC-handset-spec section 1.7.2: make contrast with MIDI ringtone chips Mychaela Falconia <falcon@freecalypso.org> parents: 64 diff changeset	562 be fed with signal from Iota AUX output instead.
46 1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	563
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	564 The loudspeaker amplifier has an on/off control by way of a Calypso GPIO; in
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	565 order to save battery, this amplifier needs to be off normally, and only turn on
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	566 when a loudspeaker call is in progress or when a ringtone melody is played.
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	567
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	568 1.7.3. Wired analog headset jack
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	569
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	570 The analog headset jack on our FC Libre Dumbphone handset will be of 2.5 mm
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	571 TRRS type, using pinout copied from iWOW DSK. The headset needs to be wired as
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	572 follows:
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	573
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	574 * 32 ohm earpiece speaker connected between Tip and Ring2;
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	575 * electret condenser microphone, positive connected to Ring1;
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	576 * Sleeve is ground, should be needed only for the microphone.
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	577
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	578 The advantage of this TRRS headset specification, as opposed to the simpler kind
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	579 with a TRS plug and a common ground for the earpiece and the mic, is that our
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	580 TRRS headset can be driven with either single-ended or differential earpiece
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	581 driver outputs. On the final handset, the wired headset interface will be
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	582 connected to the Iota headset channel (HSMICBIAS, HSMICP, HSO) and thus the
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	583 headset earpiece driver will be single-ended (HSO and GND), but the same headset
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	584 can also be plugged into other FreeCalypso devices in which the jack is wired
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	585 to the main Iota audio channel, with Iota EARP & EARN driving Tip and Ring2 on
1fec0a3f09cc FC-handset-spec: audio routing documented Mychaela Falconia <falcon@freecalypso.org> parents: 45 diff changeset	586 the TRRS headset jack.
47 f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	587
86 8df29c96327a FC-handset-spec: mention FC-HDS4, i.e., headset already made Mychaela Falconia <falcon@freecalypso.org> parents: 82 diff changeset	588 We already have an official FreeCalypso headset with a TRRS plug and BTL-wired
8df29c96327a FC-handset-spec: mention FC-HDS4, i.e., headset already made Mychaela Falconia <falcon@freecalypso.org> parents: 82 diff changeset	589 earpiece speaker as described above: it is called FC-HDS4, it was custom-made
8df29c96327a FC-handset-spec: mention FC-HDS4, i.e., headset already made Mychaela Falconia <falcon@freecalypso.org> parents: 82 diff changeset	590 for us by a professional headset manufacturer company, and we have made 100 pcs
8df29c96327a FC-handset-spec: mention FC-HDS4, i.e., headset already made Mychaela Falconia <falcon@freecalypso.org> parents: 82 diff changeset	591 at the time of our initial order in the fall of 2021 - this quantity is expected
8df29c96327a FC-handset-spec: mention FC-HDS4, i.e., headset already made Mychaela Falconia <falcon@freecalypso.org> parents: 82 diff changeset	592 to be a lifetime supply for us.
8df29c96327a FC-handset-spec: mention FC-HDS4, i.e., headset already made Mychaela Falconia <falcon@freecalypso.org> parents: 82 diff changeset	593
47 f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	594 1.8. Ringtone generation
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	595
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	596 In terms of the physical sound-emitting element, there are two principal ways
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	597 in which cellphone ringing sounds can be produced:
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	598
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	599 1) The oldest and most classic way is to use a magnetic buzzer controlled by
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	600 Calypso BU/PWT digital output. The buzzer is driven with raw battery voltage
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	601 being switched with a "digital transistor" (BJT with bias resistors), and the
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	602 control input going to the base of the BJT is Calypso BU/PWT output. This
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	603 method is standard in older phones that don't have hands-free loudspeakers:
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	604 since there is no loudspeaker for that other purpose, some loud noise-making
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	605 element needs to be implemented just for ringing, and old-style buzzers are
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	606 the traditional choice. Motorola C1xx lower subfamilies (C11x/12x and
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	607 C139/140) use such buzzers for ringing.
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	608
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	609 2) In phones that feature a loudspeaker for hands-free operation, the same
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	610 loudspeaker is also used for ringtone sounding, and the buzzer is eliminated.
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	611 Apparently hands-free loudspeakers weren't popular in the Calypso era, thus
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	612 Pirelli DP-L10 is the only known Calypso phone that features one. There is
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	613 also a more bizarre possibility: some phones have replaced the ringing buzzer
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	614 with a loudspeaker, but that speaker is used only for playing ringtone
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	615 melodies - no hands-free call feature is offered. This situation exists on
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	616 Motorola C155/156 phones.
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	617
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	618 Furthermore, if the physical sound-emitting element is a loudspeaker and not an
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	619 old-fashioned buzzer, and if the chipset is Calypso, as opposed to various newer
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	620 chipsets, then a further distinction arises:
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	621
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	622 2a) Most historical commercial phones that are based on Calypso and use a
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	623 loudspeaker for ringtone sounding, also contain a special ringtone generator
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	624 chip that drives this speaker when a ringtone is played - in other words,
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	625 their loudspeaker ringtones do NOT go through the same voice audio path that
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	626 is used for hands-free calls, if the latter feature is offered at all. The
81 3e32484f8832 FC-handset-spec: typo fix Mychaela Falconia <falcon@freecalypso.org> parents: 79 diff changeset	627 special ringtone generator chip is typically a combined MIDI player and
47 f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	628 loudspeaker driver.
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	629
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	630 2b) The much less popular approach is to not implement any extra hardware at all
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	631 that is specifically for ringtone generation, use only the same loudspeaker
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	632 audio path hardware that is already needed for hands-free calls (a simple
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	633 loudspeaker amplifier), generate ringtone melodies in the Calypso DSP
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	634 (Melody E1 or E2), and play them through the regular voice audio path,
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	635 routed to the loudspeaker.
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	636
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	637 Approach 2b is the least popular one among historical commercial Calypso phones,
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	638 but it is the one which I (Mother Mychaela) have selected for our FC Libre
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	639 Dumbphone handset. But let us nonetheless examine the pros and cons of
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	640 different approaches, and see why I have settled on option 2b.
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	641
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	642 Buzzer melodies (option 1) are monophonic (the signal carrying the melody to
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	643 the buzzer is a digital square wave, and there is no way to create multiple
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	644 overlapping notes in such a signal), but a decent range of tone frequencies is
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	645 available: the magnetic buzzer hardware can easily produce frequencies all the
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	646 way up to the limit of human hearing, while Calypso PWT produces musical notes
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	647 from F4 through E8 in the scientific pitch notation, or 349 to 5274 Hz. In
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	648 contrast, any tones produced through the 8000 samples/s voice audio path have
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	649 to be below the Nyquist frequency of 4 kHz - according to TI's document, Melody
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	650 E1 notes go from E4 (330 Hz) up to G#7 or 3322 Hz.
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	651
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	652 In terms of the richness of possible ringtone melodies that can be played,
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	653 option 2a (external MIDI player chip that drives the loudspeaker directly,
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	654 without going through Calypso+Iota voice audio path) is the absolute best.
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	655 These specialized ringtone generator chips implement full MIDI (128 instruments,
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	656 47 drums, up to 64 simultaneous notes, according to one datasheet), and the
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	657 available ringtone melodies for these MIDI chips are very rich - just take a
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	658 Pirelli DP-L10 phone and listen through various ringtone melodies it offers.
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	659 All of Pirelli's melodies are stored as *.mid files in their FFS, thus we could
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	660 very easily copy them if we were to adopt a MIDI player chip similar to theirs.
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	661
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	662 However, the problem for us with adopting option 2a is that this option would
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	663 introduce significant extra complexity and adversely affect our already long-
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	664 overdue project schedule. There is only one MIDI ringtone player chip for which
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	665 we have enough documentation to attempt such a feat: this chip is Winbond
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	666 W56964, a slightly more capable sibling of the W56940 used in the Pirelli phone.
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	667 However, just because we have what at first glance appears to be reasonably
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	668 complete documentation does not mean that it would be a slam dunk! We would
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	669 have to build a separate test board for this chip, connect it to a Caramel2
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	670 motherboard (it needs to connect to Calypso MEMIF), and then spend significant
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	671 time climbing the learning curve and getting this chip to actually work: getting
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	672 it to play melodies, and just as important, getting it into and out of sleep
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	673 modes. In other words, a lot of extra work and time spent just for this part,
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	674 not advancing any other project needs - whereas option 2b eliminates all of this
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	675 extra work.
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	676
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	677 Finally, a philosophical argument can be made that FreeCalypso should be all
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	678 about simplicity, producing a phone that does its job: implement just what is
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	679 needed for a functional phone, and omit unnecessary baggage. An extra hardware
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	680 circuit (a chip connected to Calypso memory bus, no less) and associated
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	681 software complexity that serves absolutely no other purpose except to produce
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	682 ringtones that are "richer" than what the Calypso can produce on its own, and
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	683 does not assist in any way with hands-free loudspeaker operation for calls (it
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	684 is more of a hindrance in that mode), can be seen as an unwelcome burden similar
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	685 to other unwelcome burdens which we are already eliminating, like the camera.
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	686
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	687 In contrast, with our chosen option 2b, we have exactly zero extra hardware
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	688 that is just for ringing: our loudspeaker and its associated driver circuit
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	689 (simple amplifier) is primarily for hands-free calls, and the ability to use
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	690 the same audio path to play ringtone melodies comes literally "for free" with
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	691 the Melody E1 feature built into our Calypso DSP. We already have a selection
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	692 of nice-sounding ringtone melodies in E1 format, lifted from the legendary TSM30
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	693 source, and software complexity is minimal: the melody playing engine has
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	694 already been implemented by TI, we only need to call RiViera Audio Service API
f0419ac0a815 FC-handset-spec: ringtone generation documented Mychaela Falconia <falcon@freecalypso.org> parents: 46 diff changeset	695 functions.
48 cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	696
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	697 1.9. Vibrator
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	698
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	699 All traditional cellphones include a vibrator, and ours needs to include one
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	700 too. Our firmware will need to offer the options of being silent, vibrating
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	701 only, ringing only, or ringing and vibrating on an incoming call or SMS - all
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	702 of these options are genuinely useful to a heavy-duty phone user in different
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	703 situations.
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	704
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	705 In terms of functionality, the vibrator is envisioned as a simple on/off control
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	706 in the hardware, with higher-level "pulse train" functionality implemented in
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	707 the firmware. As far as end user experience goes, the Mother's plan is to copy
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	708 the way the vibrator works on the Pirelli DP-L10. On this to-be-replaced or
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	709 to-be-recreated reference phone, the vibrator works as follows: when an incoming
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	710 call arrives in vibrating alert mode, the firmware turns the vibrator on for
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	711 500 ms, then turns it off for 500 ms, and the cycle endlessly repeats until the
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	712 call is either answered or dropped. This 500 ms on/off cycling is purely a
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	713 firmware function, the hardware control is an on/off switch.
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	714
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	715 Looking at the hardware implementation of the vibrator driving circuit in the
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	716 Motorola C1xx family and in the Pirelli DP-L10, both designs support a form of
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	717 "analog" control of the vibrator beyond simple on/off. In the Mot C1xx family
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	718 the vibrator is controlled by the output of Iota auxiliary DAC, whereas in the
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	719 Pirelli DP-L10 Calypso BU output has been repurposed to control the vibrator,
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	720 allowing either full-on or PWM driving. However, Pirelli's firmware appears to
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	721 never operate the vibrator in any way other than fully on, and there is no
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	722 evidence of Mot C1xx firmwares applying any analog control to their vibrator
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	723 either.
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	724
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	725 The Mother's tentative plan for our FC Libre Dumbphone handset is to copy
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	726 Pirelli's approach in both hardware and firmware: repurpose Calypso BU output
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	727 for vibrator control (we won't have a buzzer, see section 1.8), allowing the
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	728 possibility of PWM, but have our firmware only use fully-on and fully-off
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	729 states, at least initially. However, because we won't have a vibrator on our
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	730 Venus development board, only in the final handset, this decision does not have
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	731 to be made right now.
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	732
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	733 Because our firmware will be designed for a simple on/off vibrator control,
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	734 during fw development on the Venus board it will be trivial to use a LED to
cb8d43a5023c FC-handset-spec: vibrator documented Mychaela Falconia <falcon@freecalypso.org> parents: 47 diff changeset	735 simulate the vibrator on/off state.
49 38bcb9425df0 FC-handset-state: battery documented Mychaela Falconia <falcon@freecalypso.org> parents: 48 diff changeset	736
38bcb9425df0 FC-handset-state: battery documented Mychaela Falconia <falcon@freecalypso.org> parents: 48 diff changeset	737 1.10. Battery
38bcb9425df0 FC-handset-state: battery documented Mychaela Falconia <falcon@freecalypso.org> parents: 48 diff changeset	738
38bcb9425df0 FC-handset-state: battery documented Mychaela Falconia <falcon@freecalypso.org> parents: 48 diff changeset	739 The battery in our FC Libre Dumbphone handset will be single-cell Li-ion. It
38bcb9425df0 FC-handset-state: battery documented Mychaela Falconia <falcon@freecalypso.org> parents: 48 diff changeset	740 goes without saying that this battery will be freely removable and replaceable
38bcb9425df0 FC-handset-state: battery documented Mychaela Falconia <falcon@freecalypso.org> parents: 48 diff changeset	741 by end users. The specific size, form factor and mAh capacity of this battery
38bcb9425df0 FC-handset-state: battery documented Mychaela Falconia <falcon@freecalypso.org> parents: 48 diff changeset	742 won't be addressed until later in the project, when we get closer to building
79 468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	743 the actual handset. (2021-09 update: we are now looking at using Panasonic
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	744 NCR18650B as our canonical battery on the Venus board, but we are not yet
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	745 committing to anything for the actual handset.)
49 38bcb9425df0 FC-handset-state: battery documented Mychaela Falconia <falcon@freecalypso.org> parents: 48 diff changeset	746
38bcb9425df0 FC-handset-state: battery documented Mychaela Falconia <falcon@freecalypso.org> parents: 48 diff changeset	747 Our Calypso+Iota chipset dates from the era when the cellular handset industry
38bcb9425df0 FC-handset-state: battery documented Mychaela Falconia <falcon@freecalypso.org> parents: 48 diff changeset	748 was transitioning from NiMH to Li-ion batteries, and the Battery Charger
38bcb9425df0 FC-handset-state: battery documented Mychaela Falconia <falcon@freecalypso.org> parents: 48 diff changeset	749 Interface (BCI) block in the Iota chip supports both battery types, or at least
38bcb9425df0 FC-handset-state: battery documented Mychaela Falconia <falcon@freecalypso.org> parents: 48 diff changeset	750 TI's documentation claims so. Given that we are going against the mainstream
38bcb9425df0 FC-handset-state: battery documented Mychaela Falconia <falcon@freecalypso.org> parents: 48 diff changeset	751 society's ideas in so many other ways, I have given thought to the possibility
38bcb9425df0 FC-handset-state: battery documented Mychaela Falconia <falcon@freecalypso.org> parents: 48 diff changeset	752 of using a NiMH battery instead of Li-ion. However, the problem with using a
38bcb9425df0 FC-handset-state: battery documented Mychaela Falconia <falcon@freecalypso.org> parents: 48 diff changeset	753 NiMH battery is that we would be going into completely uncharted territory
79 468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	754 without any guidance. Here are some of the difficulties that would arise with
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	755 a NiMH battery:
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	756
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	757 1) In the case of Li-ion batteries the charging process is well-understood in
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	758 both theory and practice, and our FCHG logic based on reverse engineering of
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	759 Pirelli's firmware works well both on the same Pirelli and on Motorola C1xx
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	760 family. In contrast, if we went with NiMH, we would have absolutely no
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	761 guidance in implementing the necessary charging control logic (TI's LCC code
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	762 is useless), causing a huge risk to the project.
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	763
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	764 2) When TI designed their canonical battery charging circuit to be controlled
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	765 via Iota BCI, they assumed a charging power source that puts out somewhere
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	766 between 6 and 7 V, not 5.0 V - those were the days before USB charging. For
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	767 Li-ion batteries charging at around 500 mA, a USB +5V charging power source
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	768 is good enough, as proven by Pirelli DP-L10. However, this lower charging
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	769 voltage may not be enough for NiMH - consider the note in the Iota chip
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	770 datasheet (TWL3025_SWRS021.pdf) that reads "Ni-MH/Ni-Cd 3-cell battery
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	771 voltage can reach 5.5 V at the end of a charge cycle."
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	772
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	773 3) Determining the state of charge from Vbat for the purpose of the bars icon
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	774 is already somewhat challenging even with Li-ion, given the relatively flat
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	775 middle part of the discharge curve - and with NiMH we can only expect the
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	776 problem to be even worse, as their discharge curve is said to be even
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	777 flatter.
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	778
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	779 For these reasons, we are going to play it safe and stick with Li-ion.
50 da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	780
68 bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID Mychaela Falconia <falcon@freecalypso.org> parents: 67 diff changeset	781 1.10.1. Battery ID resistors or thermistors
bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID Mychaela Falconia <falcon@freecalypso.org> parents: 67 diff changeset	782
bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID Mychaela Falconia <falcon@freecalypso.org> parents: 67 diff changeset	783 In all classic dumbphones from the era which we seek to revive (the ones with
bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID Mychaela Falconia <falcon@freecalypso.org> parents: 67 diff changeset	784 user-removable batteries), the battery pack (flat pouch) has 3 or 4 contacts
bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID Mychaela Falconia <falcon@freecalypso.org> parents: 67 diff changeset	785 rather than just 2: in addition to battery +ve and -ve terminals, there are some
bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID Mychaela Falconia <falcon@freecalypso.org> parents: 67 diff changeset	786 ID resistors or thermistors included. Both Motorola C1xx and Pirelli DP-L10
bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID Mychaela Falconia <falcon@freecalypso.org> parents: 67 diff changeset	787 batteries have 3 contacts, and so does Nokia BL-6C battery form factor that was
bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID Mychaela Falconia <falcon@freecalypso.org> parents: 67 diff changeset	788 copied by FIC/Openmoko. In contrast, cylindrical Li-ion battery cells like
bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID Mychaela Falconia <falcon@freecalypso.org> parents: 67 diff changeset	789 18650 have no such third terminal.
bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID Mychaela Falconia <falcon@freecalypso.org> parents: 67 diff changeset	790
79 468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	791 As of this writing (2021-09), we do not anticipate using any kind of battery ID
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	792 resistors or thermistors, neither on our Venus board nor on our final handset.
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	793 FC Venus will have a provision for bringing out Iota ADIN2 like on Leonardo
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	794 (see section 3.3.1.1), but we do not anticipate actually using it. The battery
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	795 on FC Venus will most likely be an 18650; on the final handset we will most
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	796 likely either keep the same or use a custom-made flat pouch battery pack, and
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	797 if we go with the latter, it will still most likely only have two terminals.
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	798
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	799 Our current FCHG battery charging driver does not touch ADIN1 or ADIN2 at all.
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	800 Looking at TI's old PWR reference code and the disassembly of Pirelli's
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	801 firmware, it appears that when mainstream proprietary firmwares do check those
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	802 ID resistors or thermistors on ADIN1 or ADIN2, they only act as artificial
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	803 blockers: the firmware refuses to charge the battery if it sees something it
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	804 doesn't like, as opposed to using data from these sensors to tune or adjust the
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	805 charging process in some positive constructive manner. In FreeCalypso we stand
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	806 against all such artificial blocking, instead we uphold the principles of user
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	807 empowerment and personal responsibility - thus we do not currently anticipate
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	808 ever implementing any kind of ADIN1 or ADIN2 logic.
68 bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID Mychaela Falconia <falcon@freecalypso.org> parents: 67 diff changeset	809
50 da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	810 1.11. Charging circuit
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	811
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	812 Our FC Libre Dumbphone will feature a USB port (mini-B, device role only, no
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	813 OTG) that combines two logically separate functions: battery charging and
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	814 computer interface. The basic idea of this dual-function USB port comes from
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	815 Pirelli DP-L10, but we are applying significant refinements of our own to this
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	816 general idea, as the following description will make clear. This section
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	817 describes the charging function; the computer interface function is described
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	818 in section 1.12.
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	819
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	820 One highly non-standard innovation that will appear on our FC handset will be a
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	821 user-visible mechanical slide switch that will turn the charging circuit on or
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	822 off. The purpose of this charging on/off switch is to make it possible to
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	823 connect USB and have the two ttyUSB devices appear (see section 1.12) without
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	824 presenting a 'charger plug' boot condition to the Calypso+Iota core chipset.
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	825 From an end user perspective, if you only use the USB port for charging and
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	826 don't care about the computer interface function, then leave the charging switch
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	827 always on - USB plug/unplug will mean charger plug/unplug like on any
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	828 conventional phone. Similarly, if you do use the computer interface function to
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	829 connect your phone to a host computer in regular operation, with the firmware
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	830 up and running normally, but you don't mind having the phone also charge from
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	831 your computer every time you connect USB, then likewise leave the charging
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	832 switch always on. However, if you are going to reflash phone firmware or do
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	833 other advanced manipulations using the computer interface, then you will need
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	834 to turn the charging switch off. With the switch off, the USB port becomes a
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	835 computer interface only, without charging.
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	836
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	837 Past the switch, the battery charging circuit using USB +5V as the charging
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	838 power source will be the most classic one depicted in Figure 4-10 in the Iota
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	839 chip datasheet (TWL3025_SWRS021.pdf), same as in Pirelli DP-L10 and Motorola
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	840 C1xx phones. Presentation of USB +5V to Iota VCHG terminal past the charging
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	841 on/off switch is what will cause the chipset to boot in the 'charger plug' mode,
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	842 or to activate charging functions in the firmware if the phone is already on.
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	843
75 c458b7159fbd FC-handset-spec: add charging indicator LED Mychaela Falconia <falcon@freecalypso.org> parents: 74 diff changeset	844 1.11.1. Charging indicator LED
c458b7159fbd FC-handset-spec: add charging indicator LED Mychaela Falconia <falcon@freecalypso.org> parents: 74 diff changeset	845
c458b7159fbd FC-handset-spec: add charging indicator LED Mychaela Falconia <falcon@freecalypso.org> parents: 74 diff changeset	846 We are going to implement a TI-classic charging indicator LED controlled by
c458b7159fbd FC-handset-spec: add charging indicator LED Mychaela Falconia <falcon@freecalypso.org> parents: 74 diff changeset	847 Iota LEDC; the circuit is nothing more than a LED in series with a resistor,
c458b7159fbd FC-handset-spec: add charging indicator LED Mychaela Falconia <falcon@freecalypso.org> parents: 74 diff changeset	848 connected between the VCHG rail and Iota LEDC terminal. The LED will probably
c458b7159fbd FC-handset-spec: add charging indicator LED Mychaela Falconia <falcon@freecalypso.org> parents: 74 diff changeset	849 be red (TBD), such indicator LEDs have low Vf, and because the positive source
c458b7159fbd FC-handset-spec: add charging indicator LED Mychaela Falconia <falcon@freecalypso.org> parents: 74 diff changeset	850 is USB +5V rather than VBAT, there should be no issues with LED brightness
c458b7159fbd FC-handset-spec: add charging indicator LED Mychaela Falconia <falcon@freecalypso.org> parents: 74 diff changeset	851 variation.
c458b7159fbd FC-handset-spec: add charging indicator LED Mychaela Falconia <falcon@freecalypso.org> parents: 74 diff changeset	852
50 da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	853 1.12. Computer interface
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	854
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	855 Our Calypso chip has no native USB, instead the host computer interface of all
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	856 Calypso-based systems consists of two UARTs. On our development boards starting
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	857 with FCDEV3B, we got used to interfacing to both of these UARTs by way of
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	858 FT2232x adapters, a USB to serial adapter that goes from one USB device to two
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	859 UARTs, presenting two ttyUSB devices to a Linux host. For low-level operations
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	860 like flash programming, having just one Calypso UART is sufficient (either of
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	861 the two), but once our regular firmware is up and running, then having both
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	862 Calypso UARTs gives maximum user empowerment: Modem UART carries a classic AT
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	863 command interface complete with CSD, GPRS and GSM 07.10 MUX capabilities, while
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	864 the other UART (IrDA) carries TI's RVTMUX debug and development interface.
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	865
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	866 Before arriving at our current radical approach with the charging on/off switch,
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	867 for many years previously I was considering a more conservative approach. My
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	868 original idea was to bring out the two Calypso UARTs in very different ways: my
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	869 thought was to bring only the Modem UART to the built-in USB port (by way of a
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	870 built-in single-channel USB-serial chip), and have plugged-in USB always present
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	871 VCHG to the chipset, but route the debug UART (the one most useful in low-level
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	872 development and bring-up) to a special FPC connector that would interface to a
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	873 special debug board, just like Openmoko did on their Neo. Serious development
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	874 work would then require having that debug board attached, while more casual
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	875 users would be able to talk AT commands to the phone via the built-in USB port,
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	876 charging the battery at the same time.
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	877
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	878 What made me change my mind about this design was the realization that I, as the
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	879 most principal user and developer, would end up wanting to have the debug board
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	880 attached all the time, and the need to have it hanging externally, or perhaps
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	881 glued or taped to the back of the phone, would be a huge blemish and
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	882 inconvenience. Back in the days of Openmoko, someone must have had a similar
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	883 experience, as I remember reading about a hack where someone built a debug board
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	884 functional equivalent that fits inside the Neo, in some otherwise unused space.
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	885
da1a2a32c260 FC-handset-spec: USB description started Mychaela Falconia <falcon@freecalypso.org> parents: 49 diff changeset	886 Hence the new design for our planned FC Libre Dumbphone handset: the USB port
51 7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	887 will have a built-in FT2232D (or perhaps FT2232H) subsystem (USB to two UARTs)
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	888 connected to it, interfacing to both Calypso UARTs, while the charging on/off
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	889 switch will make it possible to use this interface for low-level development
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	890 and bring-up without presenting VCHG to the chipset. In this architecture this
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	891 FT2232x subsystem should be considered the primary "owner" of the handset's USB
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	892 port, while the charging function is secondary and optional, enabled or disabled
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	893 with a switch. To put it another way, if our USB port is connected to a regular
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	894 USB host (as opposed to a Dedicated Charging Port power-only source), that USB
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	895 host will always enumerate the FT2232x and see two ttyUSB devices, whereas
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	896 charging may or may not take place depending on the switch setting.
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	897
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	898 1.12.1. Set of UART signals
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	899
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	900 The set of signals to be connected between Calypso and FT2232x for the Modem
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	901 UART is almost complete:
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	902
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	903 USB UART
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	904 DTE signal Calypso signal
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	905 ------------------------------
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	906 TxD RX_MODEM
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	907 RxD TX_MODEM
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	908 RTS CTS_MODEM
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	909 CTS RTS_MODEM
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	910 DTR GPIO3
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	911 DCD GPIO2
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	912 RI GPIO8
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	913
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	914 Only DSR is omitted for the Modem UART channel, all others are included. The
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	915 second debug UART channel is only two wires:
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	916
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	917 USB UART
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	918 DTE signal Calypso signal
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	919 ------------------------------
52 cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	920 TxD2 RX_IRDA
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	921 RxD2 TX_IRDA
51 7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	922
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	923 However, as shown in the next section, these signals cannot be simply connected
52 cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	924 between Calypso and FT2232x, instead a more complicated scheme needs to be
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	925 implemented.
51 7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	926
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	927 1.12.2. USB and mobile power domains
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	928
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	929 Our FC Libre Dumbphone handset will have two principal power domains in it: the
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	930 main battery-powered mobile domain, and the USB domain. This power domain
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	931 situation presents some very significant challenges, a problem generally
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	932 referred to as "partial power-down". There are two PPD scenarios to be
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	933 concerned about:
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	934
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	935 1) In normal operation the phone is mobile and not connected to USB. In this
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	936 state the mobile power domain is on, whereas USB-powered circuits in the
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	937 FT2232x subsystem have no power. The two challenges in this state are:
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	938
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	939 1a) We need to ensure that no currents flow from the powered-on mobile domain
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	940 into powered-down USB domain circuits, as any such currents would be an
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	941 unacceptable drain on the battery.
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	942
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	943 1b) Calypso UART inputs that come from the USB domain when the latter is active
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	944 need to have defined logic levels on them when the USB domain has no power:
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	945 no floating, no mid-way levels that would cause higher currents in CMOS
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	946 input structures, and furthermore, some Calypso inputs need to be high in
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	947 this state, while others need to be low.
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	948
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	949 2) A reverse PPD scenario occurs when the USB domain has power, but the
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	950 Calypso+Iota chipset is in its switched-off state per Iota VRPC. This
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	951 scenario can occur when the charging switch is set to off, or when the
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	952 battery is critically low and undergoing precharge. The main concern in
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	953 this state is to avoid feeding power from the USB domain into the Calypso
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	954 chipset's V-IO rail - our experience on Caramel2 boards conclusively
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	955 demonstrates that Calypso does not like this condition and can behave oddly,
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	956 erratically feeding current into its outputs that are supposed to be low or
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	957 Hi-Z, and thereby erratically turning on various peripherals.
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	958
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	959 If we were to naively connect our UART signals between Calypso and FT2232x, the
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	960 result would be bad: all of the above concerns would be violated. Instead we
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	961 need to insert carefully designed isolating buffer circuits in both directions.
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	962
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	963 1.12.2.1. Calypso to FT2232x signal direction
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	964
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	965 If these signals were connected directly, significant current (in the mA range)
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	966 would flow from Calypso outputs into powered-down FT2232x inputs, which is not
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	967 acceptable. Our solution is to insert an LVC buffer (probably 74LVC541A, for
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	968 the 5 signals that are needed) between Calypso outputs and FT2232x inputs, with
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	969 the buffer powered from USB domain 3.3V supply. With mobile on and USB power
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	970 absent, the LVC buffer's Ioff spec will apply, which is listed in Nexperia's
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	971 74LVC541A datasheet as 0.1 uA typical, 10 uA maximum.
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	972
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	973 An unfortunate consequence of this design is that in the opposite PPD scenario
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	974 (USB connected to a host, charging switch off, mobile chipset in its off state)
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	975 the inputs to the LVC buffer will float, with FT2232x inputs receiving garbage
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	976 as a result. Adding pull-up resistors to a USB-domain supply would cause other
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	977 problems, hence the Mother's position is that we'll just live with a few
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	978 floating inputs in this particular condition - and it is a condition that
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	979 should not persist for extended lengths of time. There is also a software
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	980 consideration stemming from this floating input situation: when you are doing
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	981 low-level programming and development operations in this state, don't open the
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	982 Modem UART ttyUSB device, and only operate via the other debug UART. The latter
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	983 is a 2-wire UART without any flow control or modem control signals, hence there
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	984 will be less bogosity for the Linux host to see in this state.
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	985
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	986 1.12.2.2. FT2232x to Calypso signal direction
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	987
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	988 This direction is even more difficult, and we will need to insert two chained
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	989 LVC buffers: the signals will first pass through an LVC buffer powered from the
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	990 USB domain, and then through another LVC buffer powered from the Calypso+Iota
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	991 chipset's V-IO rail. There will be pull resistors inserted between the two
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	992 buffers: either pull-up to VBAT (raw battery positive rail) or pull-down to GND,
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	993 depending on the needed signal sense.
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	994
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	995 The LVC buffer powered from Calypso V-IO is needed in order to prevent current
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	996 feeding into Calypso when the mobile is switched off - the buffer's Ioff spec
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	997 will apply. Pull-up and pull-down resistors in front of this buffer are needed
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	998 so that Calypso inputs will receive the desired states when no USB host is
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	999 connected. Pull-ups are being made to VBAT instead of V-IO to eliminate the
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1000 possibility of current feeding into V-IO through these resistors. (Feeding
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1001 from 3.3V logic signals into the battery can't happen when the battery is above
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1002 3.3 V, and if the battery is below 3.3 V, then we are only adding a little to
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1003 the precharge current.)
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1004
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1005 The other LVC buffer (the one powered from USB-domain 3.3V) is needed because
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1006 in the absence of this buffer, current will flow through pull-up resistors and
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1007 into powered-down FT2232x output pins, the resulting pull-down resistance will
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1008 be lower than the pull-up, and the next buffer won't receive the desired logic
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1009 level, not to mention unwanted current flowing. With the other LVC buffer
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1010 added, that buffer's Ioff spec will apply.
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1011
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1012 The value of pull-up resistors to VBAT will be 22 kOhm. With maximum 15 uA
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1013 current flowing through each resistor (worst-case Ioff of one buffer plus
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1014 worst-case Ii of the other buffer), the maximum voltage drop on the 22 kOhm
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1015 resistor will be 330 mV. In order for the LVC buffer's input structure to not
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1016 draw extra current, the input voltage needs to be 2.8 V or higher - thus with
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1017 22 kOhm resistors we'll keep satisfying this condition until the battery falls
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1018 to about 3.1 V, which is below the operational range for switched-on mobile.
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1019
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1020 One downside of having pull-ups to VBAT (which can be as high as 4.2 V) on
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1021 signals that are output from a 3.3V-powered buffer is that when the buffer
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1022 output is high, there may be current flowing into that high output (not sourcing
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1023 out of it as normally expected), which is a bad condition for CMOS outputs.
76 04080501911d FC-handset-spec section 1.12.2.2: more accurate rounding to 41 uA Mychaela Falconia <falcon@freecalypso.org> parents: 75 diff changeset	1024 However, this current will be limited to a maximum of about 41 uA
51 7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1025 ((4.2-3.3 V) / 22 kOhm), and my feeling is that such small current won't hurt
7933c3a1b5e0 FC-handset-spec: power domain mess documented Mychaela Falconia <falcon@freecalypso.org> parents: 50 diff changeset	1026 Nexperia LVC buffers.
52 cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1027
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1028 1.12.2.2.1. Signal pull-up/down directions
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1029
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1030 Of the 4 UART signals going from FT2232x to Calypso (see section 1.12.1), TxD
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1031 and TxD2 MUST be sensed high by Calypso when no USB host is connected, hence
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1032 they will need the two chained LVC buffers with pull-ups to VBAT in between, as
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1033 described above. RTS and DTR are less critical in that either high or low level
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1034 would be acceptable, as long as it is stable and not floating. However, it is
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1035 slightly preferable to have DTR pulled up like TxD (to be sensed as logically
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1036 negated), and to have RTS (flow control signal going to CTS_MODEM) pulled down,
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1037 to be sensed as logically asserted.
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1038
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1039 The approach chosen by the Mother is to have TxD, TxD2 and DTR pulled up to VBAT
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1040 as described above, and to have RTS pulled down to GND. The value of the pull-
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1041 down resistor to GND will be 47 kOhm, and the USB-side-powered LVC buffer can be
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1042 skipped for this signal - that buffer is only needed in order to work correctly
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1043 with the pull-up to VBAT.
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1044
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1045 With only 3 FT2232x-to-Calypso signals needing to go through a USB-side-powered
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1046 LVC buffer, and with 3 slots remaining available in the 74LVC541A buffer from
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1047 section 1.12.2.1, that one 74LVC541A IC can serve both signal directions (5
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1048 signals from Calypso to FT2232x and 3 signals going the other way), reducing the
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented Mychaela Falconia <falcon@freecalypso.org> parents: 51 diff changeset	1049 component count.
53 016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1050
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1051 1.12.3. Boot control by USB host
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1052
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1053 Our DUART28C adapter (DUART28 hardware, EEPROM in the 'C' configuration) has a
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1054 nifty feature in the form of CTL1 and CTL2 open drain outputs, intended for
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1055 triggering Iota VRPC boot control signals on Calypso devices, i.e., boot control
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1056 signals from the {PWON, RPWON, nTESTRESET} set. So far none of our FreeCalypso
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1057 development boards bring out RPWON, but both FCDEV3B and Caramel2 feature PWON
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1058 and nTESTRESET controls, and we have an established convention for driving them
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1059 with CTL1 and CTL2 from a DUART28C. The end effect for the developer-operator
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1060 is that one can run operations based on Calypso boot ROM loading path (fc-iram,
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1061 fc-loadtool etc) purely from the host command line, without needing to press any
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1062 buttons on the development board: adding -Prts to the command line is equivalent
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1063 to pressing PWON, or adding -Pdtr is equivalent to pressing RESET. rvinterf can
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1064 also be run with the same options, allowing flashed firmware to be booted in a
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1065 similar no-buttons-needed manner.
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1066
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1067 It is the Mother's intent to replicate this boot control feature on our FC Libre
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1068 Dumbphone handset as well, i.e., make FT2232x Channel B RTS and DTR outputs
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1069 (otherwise unused) act as host-driven boot control triggers. In hardware terms,
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1070 this addition consists of just one tiny IC (74LVC2G07) and two pull-up resistors
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1071 on the BDBUS[24] lines from FT2232x to this OD buffer. FT2232x EEPROM will be
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1072 programmed with the same custom USB ID as DUART28C, and the Linux kernel
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1073 ftdi_sio driver will need to have our DUART28C support patch added to it.
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1074
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1075 There will be one change from our previous convention, however: the OD buffer
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1076 output controlled with Channel B RTS will be wired to RPWON rather than PWON;
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1077 the other OD buffer output controlled with Channel B DTR will still be wired to
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1078 nTESTRESET like before. The reason for this change is that our handset firmware
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1079 has more complex logic that treats different boot causes differently (as
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1080 required for standard expected handset functionality), and Iota PWON is now
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1081 reserved solely for the end user power-on button. Host-commanded boot needs to
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1082 be different from this end user power-on button (no long press is required, and
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1083 the firmware should enter its misc boot state that behaves like an ACI build),
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1084 hence we are changing the wiring so that -Prts will trigger RPWON rather than
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1085 PWON. The same boot effect can still be achieved with -Pdtr triggering
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1086 nTESTRESET, but it is a bigger hammer (reset of RTC can be unwanted), hence
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1087 -Prts will be recommended as the gentler option, leaving -Pdtr for times when
016f8cf2418c FC-handset-spec: boot control idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 52 diff changeset	1088 recovery from runaway code is needed.
54 138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1089
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1090 2. FC handset firmware functional scope specification
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1091
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1092 FreeCalypso handset firmware will always run (perhaps with subset functionality)
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1093 on more hardware targets than just our main-goal FC Libre Dumbphone handset. It
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1094 already does: our firmware currently runs on our Luna development platform, and
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1095 prior to FC it ran on TI's original D-Sample platform. A very restricted
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1096 functional subset also runs on Motorola C139 hardware.
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1097
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1098 If we consider only the main goal of FC Libre Dumbphone handset, then our
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1099 firmware evolution can be seen as strictly linear: we start with what we got
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1100 from TI, and we morph it toward what will be needed to operate our handset,
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1101 adding functionality and peripheral support which we need for our FC handset,
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1102 but which is not present in the starting point code from TI. However, we also
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1103 have side-branch functionality: at times when the code from TI supports
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1104 something which we don't need for our own FC handset, but which may be useful
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1105 for alien hardware targets, a moral imperative can be made for keeping and at
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1106 least minimally maintaining that functionality as a kind of side-branch feature,
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1107 a permitted configuration that is not needed for our own FC handset but needed
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1108 for others. Similarly, when we add support for entirely new peripherals that
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1109 are planned for our FC handset (such as the loudspeaker), we should make the
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1110 firmware change in such a way that targets without the extra feature can still
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1111 be supported. Finally, when we are changing the firmware in ways that
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1112 significantly depart from TI's original, it may sometimes be prudent to preserve
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1113 TI's original way as a lorekeeping option.
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1114
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1115 The following sections will spell out what we support and what we don't support
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1116 in FreeCalypso handset firmware, and how these scoping decisions relate to our
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1117 starting point from TI, to our main goal of FC Libre Dumbphone handset, and to
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1118 secondary objectives of alien target support and lorekeeping.
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1119
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1120 2.1. Display support
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1121
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1122 2.1.1. Support for different display sizes
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1123
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1124 By the very nature of the problem, any phone handset UI design will always be
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1125 quite specific to a particular display size in pixels, and also to the display
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1126 type as in color or black&white. The starting point code we got from TI
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1127 supports 3 different UI configurations in terms of size and coloration:
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1128
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1129 * 176x220 pixel, 16-bit color;
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1130 * 176x220 pixel B&W;
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1131 * 84x48 pixel B&W.
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1132
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1133 In FreeCalypso we have made two changes to this set of possible UI
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1134 configurations:
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1135
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1136 1) The large (176x220 pixel) B&W option has been removed. In TI's delivery this
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1137 option was nothing more than a quick&dirty hack to extend their small (84x48
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1138 pixel) B&W UI to the large D-Sample screen, and this configuration offers
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1139 nothing useful - any real display of such large size will always be color.
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1140
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1141 2) The small B&W configuration has been extended from 84x48 to 96x64 pixels.
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1142 Why 96x64? Because it is the size in pixels of Motorola C139 LCD, and it is
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1143 the smallest LCD size found among those alien Calypso phones whose existence
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1144 is known to us and for which we have at least minimal support. Extending
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1145 this UI configuration from 84x48 to 96x64 pixels was an easy change because
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1146 it is an increase in screen real estate (not a decrease), and it is a fairly
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1147 small increment, such that UI design choices which were sensible for an 84x48
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1148 pixel display are still sensible for 96x64.
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1149
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1150 The main principal difference between our approach in FreeCalypso and what a
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1151 conventional commercial phone manufacturer would have done is that we are
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1152 retaining TI's smallbw configuration and keeping it supported, as opposed to
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1153 disregarding it and working only on the bigcolor UI config for our own planned
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1154 hardware product. We keep this smallbw UI configuration around, in the extended
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1155 96x64 pixel size, for two reasons:
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1156
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1157 1) Lorekeeping: unlike TI's 176x220 pixel B&W config that was totally
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1158 uninteresting, TI's old smallbw UI (from the days of C-Sample) is
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1159 sufficiently interesting and unique (and naturally quite different from the
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1160 bigcolor version) to be worth preserving.
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1161
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1162 2) By keeping this configuration around (not discarding it and not allowing it
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1163 to bitrot beyond repair), we keep the door open for the possibility of a
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1164 minimally usable FreeCalypso Lite aftermarket firmware for Motorola C139.
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1165
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1166 Both UI configurations can be built for our current Luna platform, and both of
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1167 them display on our Luna LCD. The virtual framebuffer of 96x64 pix B&W in the
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1168 smallbw config is displayed in the center of our physical 176x220 pixel color
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1169 LCD, surrounded by a pale magenta border. The same ability to run both configs
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1170 will continue on our next development board (Venus).
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1171
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1172 2.1.2. Backlight readability paradigm
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1173
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1174 (See theoretical background in section 1.4.3.)
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1175
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1176 Our actively maintained FC handset firmware has been paradigmatically redesigned
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1177 to assume a display which is NOT readable without the backlight. Our logical
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1178 primitives with respect to display control are display on/off, rather than
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1179 backlight on/off, and we swallow the initial keypress that turns on the display.
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1180
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1181 This change is a significant departure from TI's original. The LCD on TI's
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1182 D-Sample is transflective, and when the backlight is off, the display remains
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1183 readable in ambient light. It is certainly better in this regard than Motorola
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1184 C139 LCD. And if we go back further in TI's history to C-Sample and earlier,
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1185 those 84x48 pixel B&W LCDs were the traditional mostly-reflective type,
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1186 perfectly readable without the backlight.
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1187
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1188 This area is one where we are NOT retaining TI's original way as an option in
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1189 our actively maintained firmware. The difference between the two principal
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1190 paradigms is too great, and we don't have any active-demand prospective targets
138021ca5eae FC-handset-spec: starting firmware scope description Mychaela Falconia <falcon@freecalypso.org> parents: 53 diff changeset	1191 with B&W displays of the old traditional kind.
55 df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1192
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1193 2.2. Keypad assumptions
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1194
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1195 The keypad arrangement on our FC handset (see sections 1.5 and 1.6) will be
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1196 exactly the same as on TI's D-Sample, thus no principal changes to the firmware
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1197 are needed in this regard. Furthermore, the same 21-button keypad exists on
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1198 Motorola C1xx phones, thus no firmware design variations are needed in this
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1199 regard for secondary target support.
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1200
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1201 The only issue of concern is that the 3 side buttons which exist on D-Sample and
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1202 Pirelli DP-L10 and will also exist on our FC handset don't exist on Mot C1xx.
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1203 Our starting point code from TI does not do anything with these buttons (even
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1204 though it was developed on the D-Sample platform where they exist), but when we
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1205 do get around to adding support for these side buttons, we will need to take
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1206 some extra care in preserving flexibility:
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1207
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1208 * The original code from TI uses navigation up/down buttons for volume control,
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1209 for both ringer and earpiece volume. We are going to change the code to drive
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1210 these volume controls with side buttons instead (dedicated volume up/down
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1211 buttons), but when we make this change, we'll need to provide an option of
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1212 restoring the old way for less button-equipped phones like Mot C1xx.
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1213
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1214 * Whatever functions we assign to the right side button, all of them will be
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1215 our own inventions, as none exist in TI's original code. However, this right
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1216 side button does not exist on Mot C1xx. The Mother's idea is to assign the
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1217 right side button to loudspeaker on/off control - this arrangement will work
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1218 well as the same C1xx phones that lack this button also lack the hands-free
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1219 loudspeaker.
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1220
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1221 2.2.1. No support for 18-button main keypads
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1222
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1223 Prior to D-Sample, TI's C-Sample and earlier boards had keypads with fewer
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1224 buttons, 18 instead of 21, and no side buttons. The difference between the
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1225 C-Sample 18-button main keypad and the 21-button one found on D-Sample, Pirelli
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1226 DP-L10 and Motorola C1xx is that the older 18-button keypad has only up and down
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1227 navigation buttons in the place where the 21-button version has a 5-way
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1228 navigation button group. In other words, navigation left, right and center keys
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1229 don't exist on the 18-button version.
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1230
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1231 TI's demo/prototype/PoC UI code was originally developed on C-Sample or perhaps
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1232 even earlier, thus it was originally designed for the 18-button keypad
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1233 arrangement. For this reason, the code currently makes very little use of
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1234 navigation left, right and center keys. However, some limited use is already
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1235 being made of these extra keys (primarily on text and number entry screens, aka
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1236 the editor), and our use of all available keys in the UI will keep growing. As
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1237 a matter of project scope, we are NOT supporting backward compatibility with
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1238 18-button keypads, given that the lowest-end Mot C1xx family already has
df6c61d0e817 FC-handset-spec: firmware keypad model documented Mychaela Falconia <falcon@freecalypso.org> parents: 54 diff changeset	1239 21-button keypads.
56 a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1240
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1241 2.3. Audio routing
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1242
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1243 TI's demo/prototype/PoC UI code from TCS211 does not use the audio mode facility
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1244 of the RiViera Audio Service: ABB configuration remains the default set in L1
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1245 initialization, volume control is done by calling audio_SetAmplf() in the Condat
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1246 abstraction layer, which in turn calls ABB_DlVolume(). This design will need to
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1247 change in FreeCalypso: we will start using the RiViera Audio Service audio mode
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1248 facility, and the use of this facility (including correct audio mode
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1249 configuration files under /aud in FFS) will become mandatory on all targets.
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1250
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1251 The following 3 audio modes are defined for call audio routing and idle
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1252 operation (keyclicks etc), as opposed to Melody E1 ringing covered in section
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1253 2.4.2:
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1254
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1255 Mode name Used for
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1256 ------------------------
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1257 handheld Default handheld operation and idle state
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1258 handfree Calls in hands-free loudspeaker mode
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1259 headset When a wired analog headset is plugged in
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1260
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1261 At the minimum, valid /aud/handheld.{cfg,vol} files will need to be created in
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1262 FFS on every supported target; other modes can be omitted if they can't be
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1263 entered. /aud/*.vol files maintained by RiViera Audio Service will serve as the
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1264 non-volatile volume setting store for each mode.
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1265
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1266 2.3.1. Loudspeaker inclusion or omission
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1267
66 a2857b6c3d87 FC-handset-spec section 2.3.1: change for bigcolor-spk-* configs Mychaela Falconia <falcon@freecalypso.org> parents: 65 diff changeset	1268 The Mother's plan is to conditionalize loudspeaker support on the firmware build
a2857b6c3d87 FC-handset-spec section 2.3.1: change for bigcolor-spk-* configs Mychaela Falconia <falcon@freecalypso.org> parents: 65 diff changeset	1269 configuration. Once we implement initial support for audio modes using RiViera
a2857b6c3d87 FC-handset-spec section 2.3.1: change for bigcolor-spk-* configs Mychaela Falconia <falcon@freecalypso.org> parents: 65 diff changeset	1270 Audio Service, our basic bigcolor-{gprs,vo} and smallbw configurations will
a2857b6c3d87 FC-handset-spec section 2.3.1: change for bigcolor-spk-* configs Mychaela Falconia <falcon@freecalypso.org> parents: 65 diff changeset	1271 support only handheld and headset modes, but not handfree. We will then later
a2857b6c3d87 FC-handset-spec section 2.3.1: change for bigcolor-spk-* configs Mychaela Falconia <falcon@freecalypso.org> parents: 65 diff changeset	1272 add new bigcolor-spk-* configurations whose purpose will be to support
a2857b6c3d87 FC-handset-spec section 2.3.1: change for bigcolor-spk-* configs Mychaela Falconia <falcon@freecalypso.org> parents: 65 diff changeset	1273 loudspeaker-equipped phone handset targets; these configurations will enable
a2857b6c3d87 FC-handset-spec section 2.3.1: change for bigcolor-spk-* configs Mychaela Falconia <falcon@freecalypso.org> parents: 65 diff changeset	1274 support for the hands-free loudspeaker mode (and will expect the loudspeaker
a2857b6c3d87 FC-handset-spec section 2.3.1: change for bigcolor-spk-* configs Mychaela Falconia <falcon@freecalypso.org> parents: 65 diff changeset	1275 and handfree audio mode to be available), and will also switch the ringtone
a2857b6c3d87 FC-handset-spec section 2.3.1: change for bigcolor-spk-* configs Mychaela Falconia <falcon@freecalypso.org> parents: 65 diff changeset	1276 generation mechanism from the buzzer to Melody E1 - see section 2.4.
56 a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1277
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1278 2.3.2. Headset inclusion or omission
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1279
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1280 The code supporting wired headset mode will always be included in the firmware,
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1281 however, there will be a hardware driver function call to inquire if a headset
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1282 is inserted or not. If the wired headset jack does not exist on a given target,
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1283 or more practically if it exists but we don't support it, this headset status
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1284 function will always return "no headset" indication, and the headset mode will
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1285 never be entered.
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1286
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1287 2.4. Ringtone generation
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1288
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1289 See section 1.8 for an overview of possible ways in which ringtone generation
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1290 may be accomplished. The only ring sound generation method supported by TI's
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1291 TCS211 version of their demo/prototype/PoC phone UI (the version for Calypso,
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1292 as opposed to other chipsets) is the original Calypso buzzer, i.e., Calypso
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1293 digital waveform output intended for switching a magnetic buzzer. The code that
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1294 rings this buzzer will execute successfully on every Calypso target, regardless
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1295 of whether it actually has a magnetic buzzer or not: if there is no buzzer and
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1296 Calypso BU/PWT output is left unconnected, like it is on our Luna platform, the
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1297 code will still run and emit the intended tone waveform on BU, but this output
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1298 will go nowhere and no audible sound will be made.
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1299
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1300 As a matter of project scope, in our FreeCalypso handset firmware we shall
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1301 support two configurations with regard to ringing:
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1302
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1303 1) TI's original buzzer configuration will be retained for lorekeeping and to
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1304 keep the door open for the possibility of a minimally usable FreeCalypso Lite
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1305 aftermarket firmware for Motorola C139.
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1306
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1307 2) For our own FC Libre Dumbphone handset, we will need to implement ringing by
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1308 way of the same loudspeaker that will be used for hands-free calls, using the
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1309 Melody E1 feature of Calypso DSP for ringtone melody generation.
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1310
87 78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1311 2.4.1. Approach to buzzer melodies
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1312
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1313 My (Mother Mychaela's) original intention was to limit buzzer ringing support
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1314 to the extremely crude implementation contained in the Condat audio "driver"
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1315 abstraction layer - this demo/prototype/PoC code uses BU mode rather than PWT,
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1316 and it only has one extremely basic ringing sound: alternating 800 Hz and 900 Hz
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1317 tones, no melodies. However, I have subsequently changed my mind on this point:
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1318 upon further reflection, I realized that the audio "driver" in the Condat
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1319 abstraction layer is a horrendous mess that needs to be cleaned up, and one
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1320 very helpful step in cleaning it up will be to remove buzzer functionality from
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1321 it. Toward this end, I came up with a new architecture:
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1322
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1323 * What little remains of the Condat audio "driver" layer (it will be thinned
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1324 significantly) will be only for simple audio tones (call waiting, busy,
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1325 ringing code for the calling party when the GSM network provides no IBT), and
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1326 it won't be involved in ringing, neither in the buzzer config nor in the
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1327 Melody E1 loudspeaker config.
56 a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1328
87 78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1329 * For platforms that feature a magnetic buzzer, there is a new BUZM (buzzer
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1330 melody) service implemented in RiViera land (the part of fw architecture
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1331 where such application services properly belong), and this BUZM service plays
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1332 PWT buzzer melodies, rather than BU mode. The bit-level format for these PWT
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1333 melodies is an original FreeCalypso invention, the necessary tool support for
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1334 it has been added to the FC host tools package as of fc-host-tools-r17, and
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1335 the necessary documentation is maintained in the same place.
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1336
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1337 For the end user of a FreeCalypso phone that features an old-fashioned buzzer
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1338 (e.g., FreeCalypso Lite aftermarket fw on Mot C139), the visible effect of this
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1339 architecture change is that a decent selection of varied ringtone melodies can
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1340 be implemented. A basic ring that sounds just like TI's original BU version is
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1341 still available in PWT mode (it is now composed of alternating G5 and A5 musical
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1342 notes, rather than alternating 800 Hz and 900 Hz tones, but it sounds just the
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1343 same at least to my ear), but we are now also able to play ringtone melodies of
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1344 the same rich kind as those offered by Motorola in their official firmwares for
78d4d362c086 FC-handset-spec section 2.4.1: update for PWT melodies and BUZM Mychaela Falconia <falcon@freecalypso.org> parents: 86 diff changeset	1345 buzzer-equipped phones.
56 a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1346
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1347 2.4.2. Melody E1 ringer
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1348
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1349 Our Melody E1 ringer implementation will require melody files in FFS, and we
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1350 will also have a separate audio mode (in the RiViera Audio Service sense) that
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1351 will be loaded during ringing. Even though the same physical loudspeaker will
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1352 be used for both hands-free calls and ringing, logically the two are separate
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1353 modes, and they will be treated as separate for the Audio Service. Separate
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1354 logical modes will provide separate volume files, which is the correct approach:
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1355 loudspeaker volume and ringing volume should be separate, just like how ringing
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing Mychaela Falconia <falcon@freecalypso.org> parents: 55 diff changeset	1356 volume is entirely separate when a buzzer is used.
57 020e6428c248 FC-handset-spec: firmware approach to vibrating alert documented Mychaela Falconia <falcon@freecalypso.org> parents: 56 diff changeset	1357
020e6428c248 FC-handset-spec: firmware approach to vibrating alert documented Mychaela Falconia <falcon@freecalypso.org> parents: 56 diff changeset	1358 2.5. Vibrating alert
020e6428c248 FC-handset-spec: firmware approach to vibrating alert documented Mychaela Falconia <falcon@freecalypso.org> parents: 56 diff changeset	1359
020e6428c248 FC-handset-spec: firmware approach to vibrating alert documented Mychaela Falconia <falcon@freecalypso.org> parents: 56 diff changeset	1360 Our FC handset firmware will support both ringing and vibrating alert modes (as
020e6428c248 FC-handset-spec: firmware approach to vibrating alert documented Mychaela Falconia <falcon@freecalypso.org> parents: 56 diff changeset	1361 well as a ring+vibrate mode) on all targets. The vibrator will be modeled as a
020e6428c248 FC-handset-spec: firmware approach to vibrating alert documented Mychaela Falconia <falcon@freecalypso.org> parents: 56 diff changeset	1362 simple on/off control (no "analog" control of different vibration intensity
020e6428c248 FC-handset-spec: firmware approach to vibrating alert documented Mychaela Falconia <falcon@freecalypso.org> parents: 56 diff changeset	1363 levels, at least initially), and the vibrating alert code path will ultimately
020e6428c248 FC-handset-spec: firmware approach to vibrating alert documented Mychaela Falconia <falcon@freecalypso.org> parents: 56 diff changeset	1364 boil down to a driver function call for vibrator on/off. Therefore, if the
020e6428c248 FC-handset-spec: firmware approach to vibrating alert documented Mychaela Falconia <falcon@freecalypso.org> parents: 56 diff changeset	1365 vibrator does not exist on a given target, or if it exists but we don't know how
020e6428c248 FC-handset-spec: firmware approach to vibrating alert documented Mychaela Falconia <falcon@freecalypso.org> parents: 56 diff changeset	1366 to operate it, the on/off control function can be empty on that target, and the
020e6428c248 FC-handset-spec: firmware approach to vibrating alert documented Mychaela Falconia <falcon@freecalypso.org> parents: 56 diff changeset	1367 firmware will "vibrate" virtually.
020e6428c248 FC-handset-spec: firmware approach to vibrating alert documented Mychaela Falconia <falcon@freecalypso.org> parents: 56 diff changeset	1368
020e6428c248 FC-handset-spec: firmware approach to vibrating alert documented Mychaela Falconia <falcon@freecalypso.org> parents: 56 diff changeset	1369 On development boards such as FC Venus, the vibrator on/off function can turn a
020e6428c248 FC-handset-spec: firmware approach to vibrating alert documented Mychaela Falconia <falcon@freecalypso.org> parents: 56 diff changeset	1370 LED on and off to provide an indication of the UI layers making a vibrating
020e6428c248 FC-handset-spec: firmware approach to vibrating alert documented Mychaela Falconia <falcon@freecalypso.org> parents: 56 diff changeset	1371 alert.
59 3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1372
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1373 3. Venus development board
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1374
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1375 As of the summer of 2021, FreeCalypso handset development has reached a point
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1376 where a new development board is desired, to take the place of our current Luna
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1377 development platform. The newly planned FreeCalypso development board is
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1378 codenamed Venus, and it is envisioned as serving two goals:
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1379
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1380 1) Our Venus board will be a close-to-final prototype for the actual FC handset,
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1381 as close as can be achieved in the physical form factor of a development
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1382 board meant to be used "bare" on a lab bench;
59 3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1383
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1384 2) The board will serve as the ideal firmware development platform, covering all
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1385 features and options that are listed in the previous chapter and defined as
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1386 being in scope for FC handset firmware.
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1387
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1388 The following sections spell out the design specification for this Venus
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1389 development board.
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1390
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1391 3.1. Build principle
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1392
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1393 The board will be built in the "hard" way, with the Calypso+Iota+RF chipset
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1394 implemented directly on the Venus board itself, as opposed to using a Tango
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1395 (iWOW TR-800) module. This approach is necessary because we need some Calypso
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1396 and Iota signals that are not brought out on TR-800:
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1397
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1398 1) We need Iota HSMICBIAS, HSMICP and HSO signals (the 3rd audio channel) in
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1399 addition to the primary and secondary audio channels, in order to prototype
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1400 section 1.7 hardware for the real handset, and in order to provide a proper
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1401 firmware development platform for section 2.3.
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1402
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1403 2) We need Calypso BU/PWT output so we can implement an old-fashioned buzzer,
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1404 which we need in order to develop and maintain firmware per section 2.4,
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1405 supporting both buzzer and Melody E1 ringing.
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1406
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1407 Once we have accepted that we have to bite the bullet and build our Venus board
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1408 in the "hard" way, we can also implement some other nice-to-have functions that
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1409 would have been deemed non-essential otherwise:
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1410
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1411 * We can bring out Calypso JTAG (which is not brought out on TR-800) like we did
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1412 on FCDEV3B. In the Mother's experience there is very little actual need for
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1413 Calypso JTAG, but it would be improper to omit this interface on a development
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1414 board when bringing it out is possible.
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1415
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1416 * With access to the internal ON_nOFF signal, we can implement a reliable
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1417 chipset-ON LED indicator, also like we did on FCDEV3B.
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1418
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1419 * We can implement both LPG and PWL LEDs like on the original D-Sample. Neither
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1420 LED is strictly needed for the handset firmware functional scope or for
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1421 prototyping toward the final handset; at least one LED is desired for the
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1422 purpose of indicating virtual vibrator on/off state, but similarly to other
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1423 considerations, it would be improper to pass up the opportunity to implement
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1424 both LEDs.
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1425
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1426 * Mostly unrelated to the handset project, falling instead into the realm of
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1427 general Calypso chipset knowledge recovery, I have wanted for a long time to
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1428 sniff the internal chip-to-chip VSP interface between Calypso and Iota - but
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1429 such feat cannot be accomplished on any currently existing hardware, as it's
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1430 an internal interface going from one BGA to another on PCB inner layers. If
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1431 we are building a new Calypso development board for other purposes, it would
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1432 be nifty to throw in a VSP tap header as well.
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1433
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1434 3.2. Purpose and scope
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1435
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1436 Aside from the logically unrelated VSP tap feature, our Venus board will be
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1437 intended for handset firmware development and handset hardware prototyping only.
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1438 It is not intended for non-handset directions of interest - for other interests
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1439 and purposes, use Caramel2 or FCDEV3B.
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1440
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1441 Calypso MCSI will not be available on FC Venus - in handset applications MCSI
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1442 pins are switched into GPIO mode, and we'll be using these GPIOs for LCD
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1443 backlight control on both Venus and the final handset. (Our current Luna
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1444 platform is likewise.) If you need MCSI, then you are doing modem work, not
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1445 handset, so use Caramel2 or FCDEV3B.
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1446
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1447 3.3. Handset vs. development board
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1448
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1449 The Mother's vision is that our Venus development board will be fairly close to
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1450 a final handset motherboard in terms of included hardware and general layout:
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1451 on the top side it will feature our LCD, underneath this LCD it will feature our
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1452 keypad button set, whereas the bottom side will feature the same two core
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1453 component clusters (each possibly covered by a shieldcan) as are envisioned for
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1454 the final handset: one for the mobile domain (Calypso+RF core) and one for the
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1455 USB domain (FT2232x subsystem of section 1.12). However, in terms of physical
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1456 form factor, FC Venus will still be a development board meant to be used "bare"
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1457 on a lab bench, and will exhibit the following key differences from the final
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1458 handset motherboard:
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1459
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1460 * The general form factor will be simple rectangular and unconstrained, without
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1461 highly complex mechanical design effort that will later be needed for a
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1462 handset motherboard that goes into a plastic case.
59 3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1463
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1464 * Two handset peripheral features will be omitted: the vibrator and the keypad
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1465 backlight.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1466
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1467 * There will be one additional peripheral just for the fw development platform
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1468 role of this board, as opposed to the handset prototype role: the magnetic
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1469 buzzer described in section 3.8. JTAG and VSP tap header connectors can also
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1470 be regarded as special development-board-only extra peripherals.
59 3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1471
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1472 * The physical realization of audio interfaces will be a little different from
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1473 the final handset and more appropriate for a development board, as detailed
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1474 in section 3.7.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1475
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1476 * The SIM socket and all developer-user controls and indicators will be located
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1477 on the top side of the board.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1478
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1479 3.3.1. Power supply or battery connection
59 3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1480
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1481 FC Venus will have the same orange Weidmuller power input connector as previous
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1482 TI and FreeCalypso development boards C-Sample, D-Sample, Leonardo, FCDEV3B and
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1483 Caramel2. Ready-made VBAT needs to be provided via this connector, fed directly
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1484 to the core chipset and to VBAT-powered peripherals, no on-board power
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1485 conversion. During development, operation with an AC-mains-powered fixed 3.6 V
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1486 DC supply is generally much more convenient than a real battery.
3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1487
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1488 However, in a departure from our previous development boards, it will also be
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1489 possible to connect a real Li-ion battery (instead of a fixed supply) to the
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1490 same connector - the Mother's intent is to use a common off-the-shelf 18650
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1491 battery holder and wire it up to the necessary Weidmuller plug. When a real
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1492 battery is used, it will also be possible to charge it via Calypso+Iota BCI and
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1493 FreeCalypso FCHG just like in a real handset - see the following section.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1494
79 468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	1495 Because of the need for battery-specific tuning in FCHG, it will be difficult
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	1496 to use "any" 18650 battery for the real-battery mode of operation on FC Venus -
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	1497 instead we will be on much more solid footing if we select some specific battery
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	1498 model and stick to it. The Mother's current plan is to use Panasonic NCR18650B
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	1499 as our canonical battery.
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	1500
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	1501 3.3.1.1. Iota ADIN2 connection
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	1502
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	1503 Our previous development boards FCDEV3B and Caramel2 use only pins 1 and 3 on
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	1504 the 3-pin Weidmuller battery power input connector - however, TI's Leonardo
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	1505 schematics also connect ADIN2 to the otherwise unused middle pin. Just for the
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	1506 sake of flexibility, we are going to replicate this Leonardo-style ADIN2
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	1507 connection on our Venus board, allowing the possibility of experimenting with
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	1508 battery packs that include some kind of ID resistor or thermistor and provide a
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	1509 third terminal for it. However, as of this writing (2021-09), we do not
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	1510 anticipate actually using this functionality - the Mother's current plan is to
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	1511 use an 18650 battery that does not provide any kind of third terminal.
468d43c0d8cb FC-handset-spec: document our plan of using NCR18650B Mychaela Falconia <falcon@freecalypso.org> parents: 78 diff changeset	1512
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1513 3.3.2. USB subsystem
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1514
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1515 Our Venus development board will include the same USB subsystem as intended for
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1516 the final FC Libre Dumbphone handset, as described in sections 1.11 and 1.12,
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1517 consisting of a USB mini-B interface connector, a charging on/off switch with
88 91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1518 the charging circuit behind it, and the FT2232D subsystem of section 1.12.
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1519
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1520 This design is a radical departure from our previous development boards which
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1521 bring out the two Calypso UARTs in their raw LVCMOS form, leaving the USB
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1522 interface to an external adapter, most recently our own DUART28. In fact, the
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1523 Mother's original idea for the Venus board was to keep essentially the same
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1524 interfaces as on Caramel2, retaining the use of the external DUART28 adapter
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1525 and calling for a potential separate battery+charger board - but then this
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1526 design was changed after further reflection.
69 c6dafe9f3ac2 FC-handset-spec: BCI header change on Venus Mychaela Falconia <falcon@freecalypso.org> parents: 68 diff changeset	1527
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1528 On our previous modem-centric (as opposed to handset-centric) Calypso
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1529 development boards, the USB interface was kept separate for the sake of
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1530 modularity, allowing the two Calypso UARTs to be connected to other entities
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1531 besides just USB. That design made good sense and continues to make good sense
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1532 for non-handset Calypso modem boards. However, on a handset development board
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1533 like FC Venus it becomes much more difficult to think of a realistic use case
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1534 where the two Calypso UARTs (or either one of them) would need to be connected
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1535 to something other than USB, thus this particular modularity becomes much less
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1536 of a value - while the opposite approach of integrating USB provides numerous
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1537 benefits:
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1538
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1539 * One of the primary benefits of the new Venus board over existing Luna is
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1540 significant reduction in clutter: instead of 3 separate boards (Caramel2 MB,
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1541 LCD and keypad) connected with ribbon cables, there will be just one
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1542 integrated board. If we also integrate the functionality of our DUART28C
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1543 adapter, then we reduce clutter even further.
69 c6dafe9f3ac2 FC-handset-spec: BCI header change on Venus Mychaela Falconia <falcon@freecalypso.org> parents: 68 diff changeset	1544
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1545 * In the integrated USB arrangement, the Modem UART channel's RI output (coming
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1546 from Calypso GPIO8) will be connected just like in the final handset - see
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1547 section 1.12.1. OTOH, this signal would have to be omitted if we were to use
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1548 our legacy 10-pin DUART interface and a DUART28 adapter - RI does not fit well
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1549 into that arrangement.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1550
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1551 * When development is done using an AC-mains-powered fixed DC supply and the
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1552 BSIM mode in FCHG, there still needs to be a way to present and remove VCHG.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1553 Turning on the charging switch will be more convenient than connecting a
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1554 jumper wire between a VCHG header pin and the USB +5V pin on DUART28.
59 3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1555
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1556 * If our Venus board includes complete charging circuits just like the real
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1557 handset, operation with an actual battery will become a much more practical
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1558 option. Such operation can be very useful for the purpose of giving field
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1559 demos away from FreeCalypso HQ: in such field scenarios, having to connect an
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1560 AC-mains-powered fixed DC supply may be difficult (limited space, no access
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1561 to AC power outlets, limited attention span of the audience), and furthermore,
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1562 if the demo is presented to a less technical audience, it will likely feel
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1563 more "real" if the phone prototype being demonstrated is powered by a battery
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1564 rather than an AC mains adapter. In some cases, the charging process itself
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1565 (with standard USB as the charging power source) can be made a part of the
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1566 demo.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1567
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1568 3.3.2.1. Linux kernel patch requirement
59 3ead88660a4e FC-handset-spec: started Venus board description Mychaela Falconia <falcon@freecalypso.org> parents: 58 diff changeset	1569
88 91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1570 The FT2232D USB subsystem implemented on FC Venus will include the boot control
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1571 feature originating from DUART28C, as described in section 1.12.3. This
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1572 hardware feature has an implication for developer-users of this board: anyone
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1573 wishing to play with a Venus board beyond already-flashed fw (i.e., anyone
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1574 wishing to connect the board to a host computer) will need to apply our DUART28C
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1575 support patch to the ftdi_sio driver in their Linux kernel; as for other host
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1576 OSes beyond Linux, absolutely no support exists currently, thus you would need
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1577 to do all of the necessary support-creating work yourself.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1578
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1579 The problem with the needed ftdi_sio driver patch is that it has been rejected
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1580 by mainline Linux maintainers. The patch is purely additive and non-impacting:
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1581 it simply adds support for an entirely new USB device (a new USB VID:PID) that
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1582 did not exist before, and has exactly zero impact on anything pre-existing, on
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1583 anything outside of this brand-spankin'-new USB device. But the power-wielding
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1584 maintainers rejected the patch because it isn't general enough to them, because
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1585 it serves only one specific hardware device which they don't wish to support.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1586
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1587 The Mother's answer to those Linux maintainers' game of hardball is to play back
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1588 a game of my own: our Venus boards will NOT be sold for money, not for any
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1589 price, instead they will be given out free of cost to loyal FreeCalypso
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1590 supporters. Anyone wishing to receive a Venus board will be required to apply
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1591 the non-mainlined ftdi_sio driver patch locally to their own Linux kernel, and
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1592 to show proof that they have applied this maintainer-rejected patch as a
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1593 condition of receiving their board.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1594
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1595 3.3.2.2. Board bring-up order
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1596
88 91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1597 The on-board FT2232D subsystem will be the preferred way to interface to the
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1598 two Calypso UARTs on FC Venus, and also the preferred way of driving RPWON and
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1599 nTESTRESET boot controls - if everything goes according to plan. However, to
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1600 guard against inoperable boards in the unfortunate event that the built-in USB
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1601 subsystem doesn't work as designed, there will also be a "rescue" 10-pin DUART
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1602 header on the board. If all USB subsystem components are populated on the
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1603 board as we currently intend, the "rescue" DUART header MUST NOT have anything
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1604 connected to it, other than oscilloscope probes - however, if a need arises to
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1605 operate a Venus board via an external DUART28 or other adapter, then some
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1606 components will need to be removed from the USB section of the board to prevent
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1607 the scenario of two fighting drivers.
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1608
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1609 There will also be a 3-pin boot control header, bringing out RPWON and
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1610 nTESTRESET, but this provision does not present the same stringent single driver
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1611 requirements as the "rescue" DUART header, as all drivers for these boot control
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1612 signals are open drain.
69 c6dafe9f3ac2 FC-handset-spec: BCI header change on Venus Mychaela Falconia <falcon@freecalypso.org> parents: 68 diff changeset	1613
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1614 The charging switch will need to be off during board bring-up, and it is
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1615 expected to remain off during most development activities on FC Venus, to be
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1616 turned on only rarely when exercising the charging function.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1617
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1618 3.3.3. Stepping stone toward the final handset
69 c6dafe9f3ac2 FC-handset-spec: BCI header change on Venus Mychaela Falconia <falcon@freecalypso.org> parents: 68 diff changeset	1619
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1620 When the time comes to embark on the design of the actual FC Libre Dumbphone
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1621 handset, after all necessary fw development work gets done on the Venus
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1622 development board, one of the biggest challenges will be the need for close
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1623 coordination between electronico-mechanical design of the motherboard PCBA and
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1624 ergonomico-mechanical design of the handset case. It is the Mother's hope that
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1625 by being as close as possible to the final handset motherboard while subject to
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1626 the constraints of a development board, our Venus board will serve as a useful
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1627 stepping stone toward the actual handset. When the time comes to hire a
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1628 cellphone mechanical design expert to create the mechanical design for our FC
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1629 handset, we will present a working Venus board (battery-powered and running
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1630 well-polished fw, for proper psychological impact) to our hired mechanical
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1631 designer, and hopefully this Venus board reference will work for the purpose of
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1632 communicating to that mechanical designer our requirements from the electronics
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1633 side, as in how much space is required for all of our functional components,
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1634 which will be quite different from the more recent mainstream proprietary
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1635 phones.
69 c6dafe9f3ac2 FC-handset-spec: BCI header change on Venus Mychaela Falconia <falcon@freecalypso.org> parents: 68 diff changeset	1636
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1637 In terms of electronic circuit details, our final FC Libre Dumbphone handset is
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1638 expected to be somewhat different from FC Venus, different enough to call for a
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1639 different fw build target, as a matter of fact. However, we expect that in
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1640 terms of PCB layout, these electronic circuit differences won't be heavily
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1641 disruptive, and we hope that once our hired mechanical designer gives us a
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1642 design for the handset, we will then able to transform the PCB layout of FC
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1643 Venus into the real handset motherboard.
69 c6dafe9f3ac2 FC-handset-spec: BCI header change on Venus Mychaela Falconia <falcon@freecalypso.org> parents: 68 diff changeset	1644
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1645 3.4. RF bands and PCB layout
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1646
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1647 The Mother's intent for the Venus board is to stop copying Openmoko's triband
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1648 PCB layout and instead switch to TI's original Leonardo+ quadband layout, which
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1649 has been recovered from iWOW TR-800 via professional PCB reverse engineering.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1650 We will need quadband RF for the final FC Libre Dumbphone handset, thus it would
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1651 be best to switch to it now, starting with Venus.
60 f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1652
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1653 3.5. LCD module and backlight
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1654
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1655 The LCD module on FC Venus will be Formike KWH020ST23-F01, the same LCD module
82 e279a924f7a3 FC-handset-spec: update for Formike LCD modules being here Mychaela Falconia <falcon@freecalypso.org> parents: 81 diff changeset	1656 which we have settled on for the actual FC handset. In 2021-09 we made a
e279a924f7a3 FC-handset-spec: update for Formike LCD modules being here Mychaela Falconia <falcon@freecalypso.org> parents: 81 diff changeset	1657 lifetime buy of 100 pcs of this LCD module, thus we are now past the point of
e279a924f7a3 FC-handset-spec: update for Formike LCD modules being here Mychaela Falconia <falcon@freecalypso.org> parents: 81 diff changeset	1658 considering different candidate LCD modules. Our chosen Formike LCD module is
e279a924f7a3 FC-handset-spec: update for Formike LCD modules being here Mychaela Falconia <falcon@freecalypso.org> parents: 81 diff changeset	1659 almost perfect for development boards such as FC Venus; the only blemish is
e279a924f7a3 FC-handset-spec: update for Formike LCD modules being here Mychaela Falconia <falcon@freecalypso.org> parents: 81 diff changeset	1660 that in the absence of additional mechanical restraints, an elastic force that
e279a924f7a3 FC-handset-spec: update for Formike LCD modules being here Mychaela Falconia <falcon@freecalypso.org> parents: 81 diff changeset	1661 originates somewhere in the area of the folded-under FPC tail pushes the bottom
e279a924f7a3 FC-handset-spec: update for Formike LCD modules being here Mychaela Falconia <falcon@freecalypso.org> parents: 81 diff changeset	1662 of the module upward, away from the PCB, acting against both gravity and
e279a924f7a3 FC-handset-spec: update for Formike LCD modules being here Mychaela Falconia <falcon@freecalypso.org> parents: 81 diff changeset	1663 adhesive forces. However, we have a planned workaround: we are working with a
e279a924f7a3 FC-handset-spec: update for Formike LCD modules being here Mychaela Falconia <falcon@freecalypso.org> parents: 81 diff changeset	1664 local-to-us mechanical engineering company to produce a custom retaining
e279a924f7a3 FC-handset-spec: update for Formike LCD modules being here Mychaela Falconia <falcon@freecalypso.org> parents: 81 diff changeset	1665 bracket; with the addition of this bracket, the mounting of our LCD module is
e279a924f7a3 FC-handset-spec: update for Formike LCD modules being here Mychaela Falconia <falcon@freecalypso.org> parents: 81 diff changeset	1666 expected to become secure enough for development board purposes.
67 ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	1667
ed686a290f2d FC-handset-spec: LCD and backlight specification changes Mychaela Falconia <falcon@freecalypso.org> parents: 66 diff changeset	1668 The backlight circuit design of section 1.4.4.1, which is hoped to be final, is
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1669 being included in the Venus board design. Specific LED currents don't need to
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1670 be finalized for Venus PCB layout or PCB fabrication; resistor values that set
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1671 these currents will only need to be finalized when the time comes to populate
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1672 the first fabricated Venus PCBs with components.
60 f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1673
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1674 3.6. Keypad buttons
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1675
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1676 The Mother's original intent for FC Venus was to punt on the more complex keypad
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1677 arrangement that approximates the real handset, instead continuing what we
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1678 currently have on FC Luna: a "raw" 5x5 matrix of buttons in rows and columns,
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1679 with silk screen labels indicating the function of each button, matching TI's
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1680 D-Sample. However, this plan has been changed upon further reflection - the
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1681 Mother's new thinking is that FC Venus will be a prototype toward the final
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1682 handset, a prototype as close as possible to "the real thing" while staying
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1683 within the constraints of a development board, thus the keypad arrangement needs
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1684 to be made closer to "real" as well.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1685
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1686 The main 21-button keypad described in section 1.5 will need to be implemented
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1687 on our Venus board, with the buttons in approximately correct relative
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1688 positions, all below the LCD. The buttons will be generic off-the-shelf tactile
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1689 switches with finger-accessible actuators, similar to those used on Caramel2 and
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1690 on our current Luna keypad add-on, except that SMT parts will need to be used,
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1691 in order to not put extra constraints on component placement on the opposite
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1692 side of the board. Because we won't have any overlay with button legends, we
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1693 will need to put silk screen labels on our PCB next to each button, denoting
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1694 logical functions.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1695
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1696 Out of the 21 buttons of the main keypad, 20 will fall onto KBC/KBR cross-
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1697 points, i.e., they will be "regular" keypad buttons. However, the button in the
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1698 END position (the one which is traditionally red, for power on/off and call
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1699 hang-up) will be special: in hardware terms it will be the PWON button, both on
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1700 FC Venus and on the final handset. This special arrangement exactly follows
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1701 TI's canon (D-Sample and predecessors), and has also been followed by the makers
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1702 of Pirelli DP-L10.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1703
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1704 The 3 side buttons of section 1.6 will also need to be implemented on FC Venus.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1705 The two left side buttons (volume up/down) will be placed on the left side of
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1706 our LCD, and the single right side button will be placed on the right side of
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1707 our LCD.
60 f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1708
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1709 There will be no keypad backlight on the Venus board. This secondary backlight
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1710 is not needed for firmware development, as it is not managed separately in our
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1711 fw architecture - instead its control will be absorbed into our R2D BLRR control
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1712 mechanism on the final handset where this backlight will be added.
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1713
88 91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1714 3.6.1. Limited boot control buttons
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1715
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1716 The Mother's original idea for FC Venus was to implement pushbutton switches for
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1717 all 3 boot controls as in PWON, RPWON and nTESTRESET. However, now that we are
88 91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1718 integrating the FT2232D USB subsystem of section 1.12 and the boot control
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1719 mechanism of section 1.12.3 as a non-removable part of the Venus board itself,
88 91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1720 the pushbutton switch for RPWON is being eliminated, leaving only PWON in the
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1721 "END" position in the main keypad and a rare-use RESET button. For additional
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1722 context, when I first decided to integrate the FT2232D subsystem with boot
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1723 control, I was going to drop the RESET button as well - but then I decided that
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1724 it would be more proper to include at least a footprint for one. My current
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1725 intent is to populate an actual button for RESET, but to use a different switch
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1726 part with a shorter actuator and a greater operating force, reducing the
91352355857c FC-handset-spec: document beyond-USB rescue provisions on FC Venus Mychaela Falconia <falcon@freecalypso.org> parents: 87 diff changeset	1727 probability of accidental resets.
77 da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board Mychaela Falconia <falcon@freecalypso.org> parents: 76 diff changeset	1728
60 f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1729 3.7. Audio interfaces
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1730
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1731 Corresponding to the 3 audio channels of section 1.7, there will be 3 analog
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1732 audio interfaces on FC Venus: two TRRS jacks and one 2-pin header. These audio
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1733 interfaces will be as follows:
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1734
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1735 * The main audio channel (the one that will go to the built-in earpiece speaker
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1736 and mic in the real handset) will be wired to a TRRS jack exactly like on
89 b10442b756b2 FC-handset-spec section 3.7: mention FC-HDS4 Mychaela Falconia <falcon@freecalypso.org> parents: 88 diff changeset	1737 Caramel2. The intent is that an FC-HDS4 headset will be plugged into this
b10442b756b2 FC-handset-spec section 3.7: mention FC-HDS4 Mychaela Falconia <falcon@freecalypso.org> parents: 88 diff changeset	1738 main audio jack.
60 f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1739
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1740 * The "official" headset channel (the one that will be a jack in the final
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1741 handset) will be wired to another identical TRRS jack. This other jack will
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1742 need plug insertion detection, signaled to a Calypso GPIO input.
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1743
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1744 * The output of the loudspeaker amplifier (see section 1,7.2) will be wired to
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1745 a 2-pin header exactly like on FCDEV3B, allowing the same 8 ohm lab bench
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1746 loudspeaker to be connected.
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1747
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1748 3.8. Magnetic buzzer
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1749
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1750 There will be a magnetic buzzer implemented directly on the Venus board itself
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1751 (not an externally attached component), exactly like on TI's D-Sample board.
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1752 This buzzer will be controlled by Calypso BU/PWT output in the canonical manner,
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1753 allowing the expected sounds to actually emanate when firmware operates the
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1754 old-fashioned Calypso buzzer output. See section 2.4 for the purpose of this
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1755 hardware provision.
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1756
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1757 3.9. LEDs instead of vibrator
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1758
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1759 There will be no vibrator on FC Venus - it is a mechanical function which cannot
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1760 be sensibly implemented on a development board meant for use on a lab bench.
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1761 Instead our Venus board will feature both LPG and PWL LEDs (i.e., LEDs
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1762 controlled by the respective Calypso outputs) exactly like D-Sample, and either
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented Mychaela Falconia <falcon@freecalypso.org> parents: 59 diff changeset	1763 of these LEDs can be used to simulate vibrator on/off state.
61 da5113856f3b FC-handset-spec: Venus DUART & CTL interfaces documented Mychaela Falconia <falcon@freecalypso.org> parents: 60 diff changeset	1764
62 42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1765 4. Motorola C139 port
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1766
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1767 4.1. Background information
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1768
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1769 In FreeCalypso we have low-level support for the following alien targets:
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1770
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1771 * Motorola C11x/12x
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1772 * Motorola C139/140
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1773 * Motorola C155/156
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1774 * Pirelli DP-L10
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1775 * Sony Ericsson J100
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1776
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1777 Low-level support means that for all of these targets, we are able to build and
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1778 load a FreeCalypso firmware image that boots and runs without crashing, operates
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1779 the phone's GSM radio hardware in proper spec-compliant manner (transmissions
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1780 verified with a CMU200 RF tester), and allows control via AT commands and
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1781 FreeCalypso debug & development tools fc-shell, fc-tmsh and fc-fsio. However,
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1782 in this so-called "voice pseudo-modem" (VPM) operation, the phone's LCD stays
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1783 dark, the buttons do nothing, and there are no high-level functions of any kind,
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1784 only low-level control from the attached host computer.
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1785
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1786 It also just happens that in year 2015 I (Mother Mychaela) produced a firmware
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1787 version for Mot C139 that runs untethered, without host computer connection.
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1788 However, that untethered FC-on-C139 firmware was produced as a poor man's hack,
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1789 not as an end user offering! Here is the situation we were in: we did not
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1790 discover the existence of iWOW TR-800 (an extremely obscure Calypso module)
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1791 until December of 2019, thus for the 4 years between 2015 and 2019 we had no way
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1792 of running TI's TCS211 MFW+BMI (handset configuration) firmware in its proper
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1793 D-Sample config, which is 176x220 pixel color. But we knew that TI also had an
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1794 older C-Sample UI configuration (84x48 pixel B&W), thus out of poverty, for the
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1795 lack of proper development hardware, we resurrected that old C-Sample UI config
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1796 (at first it wouldn't even compile) and got it running on Mot C139 hardware -
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1797 possible because that 84x48 pixel UI was small enough to fit into Motorola's
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1798 96x64 pixel LCD.
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1799
63 4389cd2b9d02 FC-handset-spec: grammar fix Mychaela Falconia <falcon@freecalypso.org> parents: 62 diff changeset	1800 To be clear, I never considered this hacky FC-on-C139 port to be an acceptable
62 42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1801 substitute or replacement for my real goals of first getting TI's TCS211 UI up
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1802 and running in its proper 176x220 pixel color configuration, and then producing
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1803 a FreeCalypso handset that can replace the proprietary Pirelli DP-L10. However,
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1804 a peculiar situation has arisen: we now know that it is possible to transform
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1805 Motorola C139 into a sort of Libre Dumbphone Lite with aftermarket FreeCalypso
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1806 firmware, and it is clear that some users will prefer this "liberated C139"
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1807 option over the Mother's desired FC Libre Dumbphone handset - probably for
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1808 reasons of cost more than anything, as our FC phone will likely end up costing
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1809 thousands of dollars. The rest of this chapter will explore the possibility of
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1810 practically usable FreeCalypso handset firmware on Mot C139 hardware.
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1811
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1812 4.2. Why C139?
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1813
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1814 As a matter of general principle, we could probably get our FreeCalypso Lite
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1815 firmware running on all or most of the 5 alien targets listed in section 4.1.
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1816 However, the level of usability and the set of user-available features on the
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1817 other 4 would only be worse than what we would get on C139, thus if someone is
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1818 looking for a pre-existing phone hw unit to convert to FreeCalypso Lite, then
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1819 C139 is the best choice in terms of outcome quality.
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1820
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1821 It is particularly worthy of note that if we were to get FreeCalypso Lite
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1822 firmware running on Pirelli DP-L10 (it hasn't been tried as of this writing,
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1823 but it is likely possible), the result would be not only much much worse in
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1824 functionality than Pirelli's official firmware or the Mother's desired full FC
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1825 handset, but actually even worse than the same FreeCalypso Lite firmware running
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1826 on Motorola C139! Therefore, even though the Pirelli phone serves as the
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1827 Mother's inspiration for our own FC handset hardware, the existing Pirelli
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1828 hardware is mostly useless for the purpose of turning it into a libre phone -
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1829 all because of the vast amount of completely undocumented hardware in this
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1830 model.
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1831
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1832 4.3. How to make it happen
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1833
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1834 The main reason why a practically usable FC firmware version for Mot C139 has
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1835 not been produced yet is because I, Mother Mychaela, am not willing to do it in
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1836 such a way that would jeopardize my primary goal of true FC handset hardware.
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1837 I am willing to support FreeCalypso Lite on C139 as a side addition to the
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1838 main FC handset hardware goal, but never as a replacement.
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1839
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1840 Right now my next project goal is to build my desired Venus development board.
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1841 Once that board is built, we will be in a better position to whip our TI-based
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1842 FC handset firmware into shape. No, my priorities won't change, and my initial
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1843 work on the Venus platform will be on the bigcolor firmware configuration.
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1844 However, once FC Tourmaline bigcolor firmware runs on FC Venus in a satisfactory
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1845 manner, with audio mode conversion implemented but still using the Calypso
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1846 buzzer for ringing, then it may be a good time to bring the smallbw
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1847 configuration up to par. And once FC Tourmaline smallbw runs in an end-user-
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1848 acceptable manner on FC Venus, then it will be a slam dunk to move it to actual
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1849 C139 hardware.
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1850
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1851 4.4. Functional scope limitations
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1852
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1853 Because FC Lite on Mot C139 can only ever be a side project and can never be my
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1854 main goal, I have to put some strict limits on the amount of work I am going to
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1855 do in that direction:
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1856
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1857 * The color capability of C139 physical LCD will not be used by FC Lite
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1858 firmware, instead the screen of FC-on-C139 will always be black&white. The
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1859 reason for this limitation is that displaying color on C139 would involve
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1860 actual work (a non-trivial amount of it) to create an entirely new "small
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1861 color" UI configuration (as opposed to the existing bigcolor and smallbw),
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1862 whereas the existing smallbw config is a freebie gift from TI.
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1863
90 5952e2dfdc26 FC-handset-spec section 4.4: update for current situation Mychaela Falconia <falcon@freecalypso.org> parents: 89 diff changeset	1864 * No dynamic mode switching support on the headset jack: this jack on all C1xx
5952e2dfdc26 FC-handset-spec section 4.4: update for current situation Mychaela Falconia <falcon@freecalypso.org> parents: 89 diff changeset	1865 phones serves a dual function, it is both an analog headset interface and a
5952e2dfdc26 FC-handset-spec section 4.4: update for current situation Mychaela Falconia <falcon@freecalypso.org> parents: 89 diff changeset	1866 digital interface for computer connection (UART at 2.8V logic levels), and I
5952e2dfdc26 FC-handset-spec section 4.4: update for current situation Mychaela Falconia <falcon@freecalypso.org> parents: 89 diff changeset	1867 currently have no plans to implement dynamic switching between these two
5952e2dfdc26 FC-handset-spec section 4.4: update for current situation Mychaela Falconia <falcon@freecalypso.org> parents: 89 diff changeset	1868 modes. There will be one firmware build configuration in which the jack
5952e2dfdc26 FC-handset-spec section 4.4: update for current situation Mychaela Falconia <falcon@freecalypso.org> parents: 89 diff changeset	1869 accepts Motorola headsets - serial cables won't work unless you shut down the
5952e2dfdc26 FC-handset-spec section 4.4: update for current situation Mychaela Falconia <falcon@freecalypso.org> parents: 89 diff changeset	1870 fw and operate on the phone with tools like fc-loadtool, fc-simint or our FC
5952e2dfdc26 FC-handset-spec section 4.4: update for current situation Mychaela Falconia <falcon@freecalypso.org> parents: 89 diff changeset	1871 FFS editor - and another fw build configuration in which the headset jack
5952e2dfdc26 FC-handset-spec section 4.4: update for current situation Mychaela Falconia <falcon@freecalypso.org> parents: 89 diff changeset	1872 accepts serial cables, but not actual headsets.
62 42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1873
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1874 In summary, FreeCalypso Lite on Motorola C139 will be an extremely basic and
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented Mychaela Falconia <falcon@freecalypso.org> parents: 61 diff changeset	1875 "bare bones" phone - but the hope is that it would still be useful to some.

FreeCalypso > hg > freecalypso-docs

annotate FC-handset-spec @ 103:c5f1f936dec5