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FC-handset-spec: overhaul of Mother's vision for FC Venus board
author Mychaela Falconia <falcon@freecalypso.org>
date Sun, 19 Sep 2021 03:40:13 +0000
parents 04080501911d
children a05195c86d3a
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1 FreeCalypso Handset Specification
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2 =================================
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3
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4 The purpose of this document is two-fold:
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5
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6 1) This document serves as the principal design specification for the
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7 FreeCalypso Libre Dumbphone handset hardware which I, Mother Mychaela,
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8 seek to build.
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9
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10 2) This document also defines the scope of functionality to be supported in
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11 FreeCalypso handset firmware, including support for additional hardware
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12 targets beyond the primary FC handset hw target.
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13
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14 1. FC handset hardware specification
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16 1.1. Basic features
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17
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18 The Mother's goal is to produce a replacement for the proprietary Pirelli DP-L10
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19 phone, or more specifically, for the GSM-only subset of this Pirelli phone which
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20 the Mother actually uses, *without* Pirelli's key differentiating feature of
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21 non-GSM WiFi operation, and without Pirelli's camera. The following hardware
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22 features are to be included:
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23
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24 * 176x220 pixel color display (no touch)
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25 * 21-button main keypad
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26 * 3 side buttons for volume control and an auxiliary function
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27 * hands-free loudspeaker, also to be used for ringing
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28 * vibrator
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29 * USB port that combines charging and computer interface
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30 * wired analog headset jack
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31 * single SIM slot
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32
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33 The following features which are commonly found in mainstream proprietary
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34 phones, particularly more recent ones, will NOT be included:
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35
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36 * camera
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37 * Bluetooth
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38 * FM radio
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39 * MP3 or any other music player
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40 * stereo headphone output or any other beyond-voice audio
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41 * TV receiver
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42 * GPS receiver
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43 * dual SIM slot
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44 * torch light beyond LCD and keypad backlights
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45
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46 1.2. RF band capability
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47
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48 Our FC handset needs to be quadband GSM; this quadband capability will be
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49 achieved by copying the RF section and the core PCB layout around it from the
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50 reverse-engineered iWOW TR-800 modem module, which is itself a very direct
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51 (almost verbatim) derivative of TI's Leonardo+ quadband reference design.
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53 1.3. RAM and flash
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54
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55 The Mother's intent is to use Spansion S71PL064JA0 flash+RAM MCP on the final
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56 handset motherboard, providing 8 MiB of flash and 2 MiB of XRAM in a 7x9 mm
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57 footprint. This flash and RAM capacity is already known to be fully sufficient
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58 for our FreeCalypso handset firmware in maximal feature configuration, hence
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59 any larger capacity would be excessive. However, on our FC Venus development
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60 board we may use the larger S71PL129NC0 MCP, same as used on FCDEV3B V2.
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62 1.4. Liquid crystal display
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63
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64 1.4.1. Display size
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65
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66 The size of the display for our FC Libre Dumbphone handset design is fixed at
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67 176x220 pixels, 16-bit color, following TI's D-Sample platform and the starting
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68 point UI code that was developed for it. Thoughts of changing to a different
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69 display size have been considered and rejected:
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70
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71 * If we were to change to a smaller display size, we would have to do extra work
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72 on the firmware to shrink the UI to the smaller size, and we would reduce the
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73 amount of information that can be displayed at once. We would incur extra
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74 work and a functional loss, but gain absolutely nothing in return.
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75
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76 * If we were to change to a larger display size (240x320 pixels seems to be the
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77 largest reasonable size for dumbphones, used in high-end Nokia models), we
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78 would be venturing into uncertain territory - the greatest uncertainty would
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79 be the extra CPU load on Calypso to draw the larger UI and to refresh the
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80 larger framebuffer, which is done with PIO on Calypso, without any DMA
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81 assistance. The D-Sample LCD size of 176x220 pixels already appears to be a
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82 strain in some drawing code paths, hence the Mother's decision is to play it
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83 safe and stick with the known working display size. Expanding the UI to make
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84 sensible use of larger screen real estate would also entail additional work.
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85
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86 176x220 is the display size in pixels, and this resolution number by itself says
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87 nothing about the physical display size in inches or mm. However, most readily
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88 available LCDs that are made for this pixel resolution are made in 2.0" diagonal
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89 physical size, with 31.68x39.60 mm active area and 0.180 mm dot pitch, hence
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90 this physical size is the one we are going to use.
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91
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92 1.4.2. Specific LCD module selection
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93
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94 Over the summer of 2021 we have selected Formike KWH020ST23-F01 as our LCD
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95 module for FreeCalypso; in prior years we had evaluated two other LCD modules
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96 from HaoRan and Startek. All relevant datasheets (our finally chosen LCD
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97 module, our previous candidate LCD modules and the controller ICs inside these
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98 modules) are collected here:
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99
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100 ftp://ftp.freecalypso.org/pub/embedded/LCDs/
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101
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102 Our LCD module selection criteria were as follows:
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103
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104 * TFT color LCD, 2.0" diagonal, 176x220 pixel resolution;
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105
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106 * 16-bit microprocessor bus interface;
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107
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108 * 6:00 viewing direction as appropriate for cellular handsets;
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109
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110 * backlight consisting of 3 white LEDs in parallel, joined at the anode,
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111 with separately brought-out cathodes;
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112
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113 * mechanical design that supports mounting with the FPC tail folded under the
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114 module, either by way of direct solder termination (no connector) or by way
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115 of raised sides that create sufficient vertical space to accommodate the FPC
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116 connector.
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117
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118 The requirement of 16-bit microprocessor bus interface stems from the desire to
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119 interface this LCD to the Calypso in exactly the same way how TI did it on the
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120 D-Sample, the 6:00 viewing direction and mechanical mounting requirements stem
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121 naturally from the target application (cellular phone handset), and the
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122 backlight LED wiring requirement stems from the constraints of our chosen
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123 MAX1916 backlight LED driver chip - see section 1.4.4.
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124
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125 Formike KWH020ST23-F01 is an LCD module that was discovered by Mother Mychaela
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126 in May-June of 2021, and it satisfies all of our requirements. In June of 2021
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127 we received sample pieces, then we designed a test board for the purpose of
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128 evaluating this new LCD, connecting it to our Luna interface from 2020. Our
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129 lunalcd2 test board was finally assembled in August, all tests passed, and as
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parents: 69
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130 of September we are in process of ordering a larger batch of these finally
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parents: 69
diff changeset
131 chosen Formike LCD modules.
67
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parents: 66
diff changeset
132
41
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parents:
diff changeset
133 1.4.3. Backlight and readability considerations
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parents:
diff changeset
134
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parents:
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135 Out of the various pre-existing mobile phones which I (Mychaela) have
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parents:
diff changeset
136 experienced, there have been 3 different kinds of LCDs in terms of how display
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Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
137 operation and readability interacts with the backlight:
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Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
138
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Mychaela Falconia <falcon@freecalypso.org>
parents:
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139 1) older phones with black&white LCDs: on all phones of this type which I've
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Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
140 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
141 ordinary ambient lighting, be it natural daylight or room lighting. Such
54
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Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
142 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
143 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
144 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
145 phone in darkness, such as outdoors at night or inside with all lights off.
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Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
146 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
147 functional and updated at all times, with only the backlight subject to
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Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
148 on/off control.
41
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Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
149
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Mychaela Falconia <falcon@freecalypso.org>
parents:
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150 2) most newer phones with color displays, of which Pirelli DP-L10 is a
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Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
151 representative case, have transmissive LCDs that are not designed to be
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Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
152 readable without the backlight at all - backlight required for readability
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Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
153 (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
154 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
155 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
156 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
157 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
158 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
159 the regular action of whatever button was pressed to "wake up" the display.
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Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
160
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Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
161 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
162 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
163 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
164 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
165 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
166 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
167 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
168 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
169 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
170 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
171 to make the display readable.
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
172
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Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
173 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
174 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
175 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
176 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
177 firmware operating like Pirelli's in terms of wake-up keypress swallowing.
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Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
178
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
179 1.4.3.1. Backlight dimming mode
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
180
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
181 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
182 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
183 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
184 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
185 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
186 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
187 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
188 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
189 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
190 (but still readable) state keypresses are NOT swallowed.
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
191
67
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Mychaela Falconia <falcon@freecalypso.org>
parents: 66
diff changeset
192 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
193 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
194 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
195 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
196 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
197 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
198 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
199 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
200 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
201 see section 1.4.4.1.
41
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Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
202
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
203 1.4.4. Backlight circuit implementation
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
204
73
eb68975e1b81 FC-handset-spec: KWH020ST23-F01 finalized
Mychaela Falconia <falcon@freecalypso.org>
parents: 69
diff changeset
205 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
206 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
207 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
208 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
209 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
210 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
211 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
212 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
213 typical) to perhaps as high as 3.4 V (what one datasheet lists as the maximum).
41
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Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
214
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
215 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
216 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
217 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
218 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
219 current), hence we need to avoid using such.
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
220
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
221 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
222 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
223 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
224 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
225 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
226 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
227 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
228 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
229 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
230 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
231 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
232 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
233
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
234 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
235 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
236 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
237 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
238 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
239 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
240 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
241 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
242 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
243 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
244 variations in Vf.
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
245
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
246 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
247 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
248 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
249 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
250 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
251 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
252 series resistors, connect each cathode to the corresponding LEDn pin of MAX1916
7d77aa76bcaa FC-handset-spec: beginning of massive document
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parents:
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253 - *without* any resistors or transistors! FETs inside the MAX1916 take the
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Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
254 place of resistors as current-limiting elements, and the chip's global on/off
44
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parents: 43
diff changeset
255 control (which will be driven with a Calypso GPIO) takes the place of a separate
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Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
256 switching transistor.
41
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parents:
diff changeset
257
7d77aa76bcaa FC-handset-spec: beginning of massive document
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parents:
diff changeset
258 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
259 LED (based on a set reference current and 230x current multiplication circuit
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Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
260 inside the chip) regardless of variations in both Vbat and Vf! Of course the
67
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Mychaela Falconia <falcon@freecalypso.org>
parents: 66
diff changeset
261 requested current can only be sustained as long as Vbat >= Vf + Vds_min, where
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Mychaela Falconia <falcon@freecalypso.org>
parents: 66
diff changeset
262 Vds_min is the lowest drop voltage of the FETs inside MAX1916, and once Vbat
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Mychaela Falconia <falcon@freecalypso.org>
parents: 66
diff changeset
263 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
264 beauty of this design is that no arbitrary artificial turnover points (like the
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Mychaela Falconia <falcon@freecalypso.org>
parents: 66
diff changeset
265 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
266 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
267 whatever it comes to be naturally, based on Vf (perhaps depending on
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Mychaela Falconia <falcon@freecalypso.org>
parents: 66
diff changeset
268 temperature) and MAX1916 Vds_min, and the decline is expected to be gradual.
41
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parents:
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269
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parents:
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270 1.4.4.1. Backlight current selection and dimming
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parents:
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271
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parents:
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272 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:
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273 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
274 regulated fixed voltage rail happens to be available in the system. However,
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Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
275 in our application (see section 1.4.3.1) we need at least two different display
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Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
276 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
277 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
278
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
279 LCD backlight LED current will be selected by way of two Calypso GPIO pins
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
280 configured as outputs, and a 74LVC2G125 dual tristate buffer. Each tristate
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
281 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:
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282 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
283 different carefully computed values, each connected between one of the two
67
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Mychaela Falconia <falcon@freecalypso.org>
parents: 66
diff changeset
284 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
285 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
286
ed686a290f2d FC-handset-spec: LCD and backlight specification changes
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parents: 66
diff changeset
287 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
288 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
289 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
290 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
291 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
292 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
293 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
294 of 4 different backlight intensity levels to be selected via the two Calypso
ed686a290f2d FC-handset-spec: LCD and backlight specification changes
Mychaela Falconia <falcon@freecalypso.org>
parents: 66
diff changeset
295 GPIO outputs going to the 74LVC2G125 buffer's output enable inputs. The actual
73
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Mychaela Falconia <falcon@freecalypso.org>
parents: 69
diff changeset
296 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
297 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
298 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
299 increments.
41
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Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
300
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
301 1.4.5. Slight regression relative to Pirelli DP-L10
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Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
302
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
303 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
304 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
305 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
306 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
307 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
308 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
309 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
310 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
311 possible LED currents.
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
312
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
313 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
314 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
315 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
316 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
317 128/255, 192/255 and 255/255 in the resulting PWL programming.
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Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
318
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
319 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
320 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
321 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
322 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
323 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
324 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
325 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
326 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
327 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
328 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
329 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
330
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
331 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
332 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
333 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
334 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
335 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
336 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
337 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
338 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
339 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
340 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
341 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
342 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
343 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
344 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
345 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
346 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
347 induced reductions, just the natural one.
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
348
7d77aa76bcaa FC-handset-spec: beginning of massive document
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
349 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
350 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
351 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
352
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
353 1.5. Main keypad
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
354
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
355 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
356 21-button arrangement:
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
357
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
358 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
359 <O>
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
360 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
361 button button
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
362
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
363 1 2 3
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
364 4 5 6
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
365 7 8 9
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
366 * 0 #
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 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
369 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
370 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
371 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
372 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
373 a firmware function.
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
374
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
375 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
376 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
377 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
378 Samsung E2232.
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
379
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
380 1.5.1. Keypad backlight
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
381
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
382 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
383 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
384 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
385 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
386 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
387 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
388 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
389
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
390 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
391 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
392 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
393 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
394
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
395 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
396 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
397 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
398 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
399 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
400 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
401 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
402 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
403
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
404 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
405 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
406 (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
407 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
408 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
409
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
410 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
411
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
412 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
413 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
414 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
415 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
416 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
417
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
418 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
419 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
420 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
421 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
422 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
423 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
424 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
425 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
426 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
427 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
428 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
429 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
430 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
431
a415ae467c6d FC-handset-spec: main keypad and its backlight documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 43
diff changeset
432 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
433 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
434 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
435 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
436
9df8683daec4 FC-handset-spec: side buttons documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 44
diff changeset
437 1.6. Side buttons
9df8683daec4 FC-handset-spec: side buttons documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 44
diff changeset
438
9df8683daec4 FC-handset-spec: side buttons documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 44
diff changeset
439 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
440 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
441 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
442 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
443 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
444 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
445 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
446 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
447 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
448 purposes of our own invention.
9df8683daec4 FC-handset-spec: side buttons documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 44
diff changeset
449
9df8683daec4 FC-handset-spec: side buttons documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 44
diff changeset
450 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
451 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
452 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
453 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
454
9df8683daec4 FC-handset-spec: side buttons documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 44
diff changeset
455 * 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
456 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
457 TI.
9df8683daec4 FC-handset-spec: side buttons documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 44
diff changeset
458
9df8683daec4 FC-handset-spec: side buttons documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 44
diff changeset
459 * 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
460 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
461 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
462 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
463 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
464 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
465 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
466 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
467 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
468 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
469 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
470 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
471 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
472 off.
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 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
475 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
476 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
477 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
478 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
479 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
480 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
481 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
482
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
483 1.7. Audio routing
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
484
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
485 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
486 handset:
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
487
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
488 * 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
489 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
490 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
491 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
492
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
493 * 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
494 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
495 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
496 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
497 same.
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
498
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
499 * 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
500 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
501 headset interface.
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 1.7.1. Earpiece and loudspeaker separation
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
504
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
505 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
506 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
507 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
508 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
509 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
510 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
511 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
512 by Iota EAR output.
46
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 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
515 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
516 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
517 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
518 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
519 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
520 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
521 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
522 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
523 traditional 32 ohm earpiece speaker.
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
524
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
525 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
526 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
527 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
528 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
529 arrangement as D-Sample and Leonardo.
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
530
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
531 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
532 architecture, using physically separate earpiece and loudspeaker transducers.
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
533 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
534 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
535 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
536 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
537 earpiece physical position seems very uncommon.
46
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
538
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
539 1.7.2. Loudspeaker implementation
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
540
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
541 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
542 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
543 "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
544 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
545 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
546 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
547 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
548
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
549 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
550 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
551 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
552
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
553 1.7.3. Wired analog headset jack
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
554
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
555 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
556 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
557 follows:
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
558
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
559 * 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
560 * electret condenser microphone, positive connected to Ring1;
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
561 * 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
562
1fec0a3f09cc FC-handset-spec: audio routing documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 45
diff changeset
563 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
564 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
565 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
566 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
567 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
568 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
569 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
570 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
571 the TRRS headset jack.
47
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
572
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
573 1.8. Ringtone generation
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
574
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
575 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
576 in which cellphone ringing sounds can be produced:
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
577
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
578 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
579 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
580 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
581 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
582 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
583 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
584 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
585 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
586 C139/140) use such buzzers for ringing.
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
587
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
588 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
589 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
590 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
591 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
592 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
593 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
594 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
595 Motorola C155/156 phones.
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
596
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
597 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
598 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
599 chipsets, then a further distinction arises:
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
600
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
601 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
602 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
603 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
604 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
605 is used for hands-free calls, if the latter feature is offered at all. The
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
606 speciai ringtone generator chip is typically a combined MIDI player and
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
607 loudspeaker driver.
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 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
610 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
611 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
612 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
613 (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
614 routed to the loudspeaker.
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
615
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
616 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
617 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
618 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
619 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
620
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
621 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
622 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
623 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
624 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
625 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
626 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
627 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
628 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
629 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
630
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
631 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
632 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
633 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
634 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
635 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
636 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
637 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
638 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
639 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
640
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
641 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
642 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
643 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
644 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
645 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
646 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
647 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
648 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
649 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
650 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
651 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
652 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
653 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
654 extra work.
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
655
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
656 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
657 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
658 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
659 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
660 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
661 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
662 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
663 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
664 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
665
f0419ac0a815 FC-handset-spec: ringtone generation documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 46
diff changeset
666 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
667 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
668 (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
669 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
670 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
671 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
672 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
673 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
674 functions.
48
cb8d43a5023c FC-handset-spec: vibrator documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 47
diff changeset
675
cb8d43a5023c FC-handset-spec: vibrator documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 47
diff changeset
676 1.9. Vibrator
cb8d43a5023c FC-handset-spec: vibrator documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 47
diff changeset
677
cb8d43a5023c FC-handset-spec: vibrator documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 47
diff changeset
678 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
679 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
680 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
681 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
682 situations.
cb8d43a5023c FC-handset-spec: vibrator documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 47
diff changeset
683
cb8d43a5023c FC-handset-spec: vibrator documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 47
diff changeset
684 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
685 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
686 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
687 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
688 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
689 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
690 500 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
691 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
692 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
693
cb8d43a5023c FC-handset-spec: vibrator documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 47
diff changeset
694 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
695 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
696 "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
697 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
698 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
699 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
700 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
701 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
702 either.
cb8d43a5023c FC-handset-spec: vibrator documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 47
diff changeset
703
cb8d43a5023c FC-handset-spec: vibrator documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 47
diff changeset
704 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
705 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
706 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
707 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
708 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
709 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
710 to be made right now.
cb8d43a5023c FC-handset-spec: vibrator documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 47
diff changeset
711
cb8d43a5023c FC-handset-spec: vibrator documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 47
diff changeset
712 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
713 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
714 simulate the vibrator on/off state.
49
38bcb9425df0 FC-handset-state: battery documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 48
diff changeset
715
38bcb9425df0 FC-handset-state: battery documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 48
diff changeset
716 1.10. Battery
38bcb9425df0 FC-handset-state: battery documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 48
diff changeset
717
38bcb9425df0 FC-handset-state: battery documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 48
diff changeset
718 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
719 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
720 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
721 won't be addressed until later in the project, when we get closer to building
38bcb9425df0 FC-handset-state: battery documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 48
diff changeset
722 the actual handset.
38bcb9425df0 FC-handset-state: battery documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 48
diff changeset
723
38bcb9425df0 FC-handset-state: battery documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 48
diff changeset
724 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
725 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
726 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
727 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
728 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
729 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
730 NiMH battery is that we would be going into completely uncharted territory
38bcb9425df0 FC-handset-state: battery documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 48
diff changeset
731 without any guidance. In the case of Li-ion batteries the charging process is
38bcb9425df0 FC-handset-state: battery documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 48
diff changeset
732 well-understood in both theory and practice, and our FCHG logic based on reverse
38bcb9425df0 FC-handset-state: battery documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 48
diff changeset
733 engineering of Pirelli's firmware works well both on the same Pirelli and on
38bcb9425df0 FC-handset-state: battery documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 48
diff changeset
734 Motorola C1xx family. In contrast, if we went with NiMH, we would have
38bcb9425df0 FC-handset-state: battery documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 48
diff changeset
735 absolutely no guidance in implementing the necessary charging control logic
38bcb9425df0 FC-handset-state: battery documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 48
diff changeset
736 (TI's LCC code is useless), causing a huge risk to the project. Furthermore,
38bcb9425df0 FC-handset-state: battery documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 48
diff changeset
737 determining the state of charge from Vbat for the purpose of the bars icon is
38bcb9425df0 FC-handset-state: battery documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 48
diff changeset
738 already somewhat challenging even with Li-ion, given the relatively flat middle
38bcb9425df0 FC-handset-state: battery documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 48
diff changeset
739 part of the discharge curve - and with NiMH we can only expect the problem to be
38bcb9425df0 FC-handset-state: battery documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 48
diff changeset
740 even worse, as their discharge curve is said to be even flatter. For these
38bcb9425df0 FC-handset-state: battery documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 48
diff changeset
741 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
742
68
bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID
Mychaela Falconia <falcon@freecalypso.org>
parents: 67
diff changeset
743 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
744
bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID
Mychaela Falconia <falcon@freecalypso.org>
parents: 67
diff changeset
745 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
746 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
747 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
748 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
749 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
750 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
751 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
752
bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID
Mychaela Falconia <falcon@freecalypso.org>
parents: 67
diff changeset
753 Because we are deferring our handset battery design to a later project phase
bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID
Mychaela Falconia <falcon@freecalypso.org>
parents: 67
diff changeset
754 (not included on the Venus board), we don't know at this time whether or not
bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID
Mychaela Falconia <falcon@freecalypso.org>
parents: 67
diff changeset
755 our final handset battery pack will have any ID resistor and/or thermistor
bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID
Mychaela Falconia <falcon@freecalypso.org>
parents: 67
diff changeset
756 connected to Iota ADIN1 or ADIN2. Our current FCHG battery charging driver
bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID
Mychaela Falconia <falcon@freecalypso.org>
parents: 67
diff changeset
757 does not touch ADIN1 or ADIN2 at all; if we do end up having an ID resistor or
bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID
Mychaela Falconia <falcon@freecalypso.org>
parents: 67
diff changeset
758 thermistor and needing to support it, that custom support will have to be added
bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID
Mychaela Falconia <falcon@freecalypso.org>
parents: 67
diff changeset
759 at the time of the actual handset design.
bdc5d8d9fa1f FC-handset-spec: new section 1.10.1 clarifies battery ID
Mychaela Falconia <falcon@freecalypso.org>
parents: 67
diff changeset
760
50
da1a2a32c260 FC-handset-spec: USB description started
Mychaela Falconia <falcon@freecalypso.org>
parents: 49
diff changeset
761 1.11. Charging circuit
da1a2a32c260 FC-handset-spec: USB description started
Mychaela Falconia <falcon@freecalypso.org>
parents: 49
diff changeset
762
da1a2a32c260 FC-handset-spec: USB description started
Mychaela Falconia <falcon@freecalypso.org>
parents: 49
diff changeset
763 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
764 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
765 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
766 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
767 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
768 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
769 in section 1.12.
da1a2a32c260 FC-handset-spec: USB description started
Mychaela Falconia <falcon@freecalypso.org>
parents: 49
diff changeset
770
da1a2a32c260 FC-handset-spec: USB description started
Mychaela Falconia <falcon@freecalypso.org>
parents: 49
diff changeset
771 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
772 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
773 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
774 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
775 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
776 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
777 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
778 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
779 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
780 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
781 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
782 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
783 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
784 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
785 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
786 computer interface only, without charging.
da1a2a32c260 FC-handset-spec: USB description started
Mychaela Falconia <falcon@freecalypso.org>
parents: 49
diff changeset
787
da1a2a32c260 FC-handset-spec: USB description started
Mychaela Falconia <falcon@freecalypso.org>
parents: 49
diff changeset
788 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
789 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
790 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
791 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
792 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
793 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
794
75
c458b7159fbd FC-handset-spec: add charging indicator LED
Mychaela Falconia <falcon@freecalypso.org>
parents: 74
diff changeset
795 1.11.1. Charging indicator LED
c458b7159fbd FC-handset-spec: add charging indicator LED
Mychaela Falconia <falcon@freecalypso.org>
parents: 74
diff changeset
796
c458b7159fbd FC-handset-spec: add charging indicator LED
Mychaela Falconia <falcon@freecalypso.org>
parents: 74
diff changeset
797 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
798 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
799 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
800 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
801 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
802 variation.
c458b7159fbd FC-handset-spec: add charging indicator LED
Mychaela Falconia <falcon@freecalypso.org>
parents: 74
diff changeset
803
50
da1a2a32c260 FC-handset-spec: USB description started
Mychaela Falconia <falcon@freecalypso.org>
parents: 49
diff changeset
804 1.12. Computer interface
da1a2a32c260 FC-handset-spec: USB description started
Mychaela Falconia <falcon@freecalypso.org>
parents: 49
diff changeset
805
da1a2a32c260 FC-handset-spec: USB description started
Mychaela Falconia <falcon@freecalypso.org>
parents: 49
diff changeset
806 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
807 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
808 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
809 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
810 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
811 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
812 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
813 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
814 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
815 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
816
da1a2a32c260 FC-handset-spec: USB description started
Mychaela Falconia <falcon@freecalypso.org>
parents: 49
diff changeset
817 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
818 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
819 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
820 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
821 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
822 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
823 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
824 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
825 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
826 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
827 charging the battery at the same time.
da1a2a32c260 FC-handset-spec: USB description started
Mychaela Falconia <falcon@freecalypso.org>
parents: 49
diff changeset
828
da1a2a32c260 FC-handset-spec: USB description started
Mychaela Falconia <falcon@freecalypso.org>
parents: 49
diff changeset
829 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
830 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
831 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
832 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
833 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
834 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
835 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
836
da1a2a32c260 FC-handset-spec: USB description started
Mychaela Falconia <falcon@freecalypso.org>
parents: 49
diff changeset
837 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
838 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
839 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
840 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
841 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
842 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
843 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
844 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
845 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
846 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
847 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
848
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
849 1.12.1. Set of UART signals
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
850
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
851 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
852 UART is almost complete:
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
853
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
854 USB UART
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
855 DTE signal Calypso signal
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
856 ------------------------------
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
857 TxD RX_MODEM
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
858 RxD TX_MODEM
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
859 RTS CTS_MODEM
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
860 CTS RTS_MODEM
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
861 DTR GPIO3
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
862 DCD GPIO2
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
863 RI GPIO8
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
864
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
865 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
866 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
867
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
868 USB UART
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
869 DTE signal Calypso signal
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
870 ------------------------------
52
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 51
diff changeset
871 TxD2 RX_IRDA
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 51
diff changeset
872 RxD2 TX_IRDA
51
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
873
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
874 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
875 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
876 implemented.
51
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
877
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
878 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
879
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
880 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
881 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
882 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
883 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
884 concerned about:
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
885
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
886 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
887 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
888 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
889
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
890 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
891 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
892 unacceptable drain on the battery.
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
893
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
894 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
895 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
896 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
897 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
898 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
899
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
900 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
901 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
902 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
903 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
904 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
905 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
906 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
907 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
908 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
909
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
910 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
911 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
912 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
913
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
914 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
915
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
916 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
917 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
918 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
919 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
920 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
921 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
922 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
923
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
924 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
925 (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
926 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
927 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
928 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
929 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
930 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
931 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
932 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
933 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
934 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
935 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
936
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
937 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
938
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
939 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
940 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
941 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
942 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
943 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
944 depending on the needed signal sense.
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
945
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
946 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
947 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
948 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
949 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
950 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
951 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
952 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
953 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
954 the precharge current.)
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
955
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
956 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
957 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
958 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
959 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
960 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
961 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
962
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
963 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
964 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
965 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
966 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
967 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
968 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
969 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
970
7933c3a1b5e0 FC-handset-spec: power domain mess documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 50
diff changeset
971 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
972 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
973 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
974 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
975 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
976 ((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
977 Nexperia LVC buffers.
52
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 51
diff changeset
978
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 51
diff changeset
979 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
980
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 51
diff changeset
981 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
982 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
983 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
984 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
985 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
986 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
987 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
988 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
989
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 51
diff changeset
990 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
991 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
992 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
993 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
994 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
995
cfe8623b915d FC-handset-spec: UART signal pull-up/down documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 51
diff changeset
996 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
997 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
998 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
999 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
1000 component count.
53
016f8cf2418c FC-handset-spec: boot control idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 52
diff changeset
1001
016f8cf2418c FC-handset-spec: boot control idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 52
diff changeset
1002 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
1003
016f8cf2418c FC-handset-spec: boot control idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 52
diff changeset
1004 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
1005 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
1006 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
1007 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
1008 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
1009 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
1010 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
1011 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
1012 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
1013 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
1014 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
1015 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
1016 similar no-buttons-needed manner.
016f8cf2418c FC-handset-spec: boot control idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 52
diff changeset
1017
016f8cf2418c FC-handset-spec: boot control idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 52
diff changeset
1018 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
1019 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
1020 (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
1021 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
1022 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
1023 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
1024 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
1025
016f8cf2418c FC-handset-spec: boot control idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 52
diff changeset
1026 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
1027 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
1028 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
1029 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
1030 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
1031 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
1032 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
1033 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
1034 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
1035 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
1036 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
1037 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
1038 -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
1039 recovery from runaway code is needed.
54
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1040
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1041 2. FC handset firmware functional scope specification
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1042
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1043 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
1044 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
1045 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
1046 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
1047 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
1048
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1049 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
1050 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
1051 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
1052 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
1053 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
1054 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
1055 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
1056 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
1057 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
1058 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
1059 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
1060 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
1061 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
1062 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
1063 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
1064 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
1065
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1066 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
1067 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
1068 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
1069 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
1070
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1071 2.1. Display support
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1072
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1073 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
1074
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1075 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
1076 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
1077 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
1078 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
1079
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1080 * 176x220 pixel, 16-bit color;
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1081 * 176x220 pixel B&W;
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1082 * 84x48 pixel B&W.
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1083
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1084 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
1085 configurations:
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1086
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1087 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
1088 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
1089 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
1090 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
1091
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1092 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
1093 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
1094 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
1095 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
1096 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
1097 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
1098 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
1099 pixel display are still sensible for 96x64.
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1100
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1101 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
1102 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
1103 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
1104 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
1105 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
1106 96x64 pixel size, for two reasons:
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1107
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1108 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
1109 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
1110 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
1111 bigcolor version) to be worth preserving.
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1112
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1113 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
1114 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
1115 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
1116
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1117 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
1118 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
1119 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
1120 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
1121 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
1122
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1123 2.1.2. Backlight readability paradigm
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1124
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1125 (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
1126
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1127 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
1128 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
1129 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
1130 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
1131
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1132 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
1133 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
1134 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
1135 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
1136 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
1137 perfectly readable without the backlight.
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1138
138021ca5eae FC-handset-spec: starting firmware scope description
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
1139 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
1140 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
1141 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
1142 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
1143
df6c61d0e817 FC-handset-spec: firmware keypad model documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 54
diff changeset
1144 2.2. Keypad assumptions
df6c61d0e817 FC-handset-spec: firmware keypad model documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 54
diff changeset
1145
df6c61d0e817 FC-handset-spec: firmware keypad model documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 54
diff changeset
1146 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
1147 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
1148 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
1149 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
1150 regard for secondary target support.
df6c61d0e817 FC-handset-spec: firmware keypad model documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 54
diff changeset
1151
df6c61d0e817 FC-handset-spec: firmware keypad model documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 54
diff changeset
1152 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
1153 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
1154 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
1155 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
1156 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
1157 some extra care in preserving flexibility:
df6c61d0e817 FC-handset-spec: firmware keypad model documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 54
diff changeset
1158
df6c61d0e817 FC-handset-spec: firmware keypad model documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 54
diff changeset
1159 * 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
1160 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
1161 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
1162 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
1163 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
1164
df6c61d0e817 FC-handset-spec: firmware keypad model documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 54
diff changeset
1165 * 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
1166 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
1167 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
1168 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
1169 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
1170 loudspeaker.
df6c61d0e817 FC-handset-spec: firmware keypad model documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 54
diff changeset
1171
df6c61d0e817 FC-handset-spec: firmware keypad model documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 54
diff changeset
1172 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
1173
df6c61d0e817 FC-handset-spec: firmware keypad model documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 54
diff changeset
1174 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
1175 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
1176 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
1177 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
1178 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
1179 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
1180 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
1181
df6c61d0e817 FC-handset-spec: firmware keypad model documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 54
diff changeset
1182 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
1183 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
1184 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
1185 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
1186 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
1187 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
1188 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
1189 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
1190 21-button keypads.
56
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1191
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1192 2.3. Audio routing
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1193
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1194 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
1195 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
1196 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
1197 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
1198 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
1199 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
1200 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
1201
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1202 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
1203 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
1204 2.4.2:
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1205
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1206 Mode name Used for
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1207 ------------------------
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1208 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
1209 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
1210 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
1211
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1212 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
1213 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
1214 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
1215 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
1216
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1217 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
1218
66
a2857b6c3d87 FC-handset-spec section 2.3.1: change for bigcolor-spk-* configs
Mychaela Falconia <falcon@freecalypso.org>
parents: 65
diff changeset
1219 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
1220 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
1221 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
1222 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
1223 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
1224 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
1225 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
1226 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
1227 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
1228
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1229 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
1230
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1231 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
1232 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
1233 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
1234 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
1235 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
1236 never be entered.
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1237
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1238 2.4. Ringtone generation
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1239
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1240 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
1241 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
1242 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
1243 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
1244 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
1245 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
1246 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
1247 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
1248 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
1249 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
1250
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1251 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
1252 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
1253
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1254 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
1255 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
1256 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
1257
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1258 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
1259 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
1260 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
1261
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1262 2.4.1. Scope limitation on buzzer melodies
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1263
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1264 Because the option of ringing via Calypso buzzer output is retained only for
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1265 lorekeeping and for minimal-support alien targets, no effort will be expended
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1266 toward playing more musical melodies via the buzzer. Our current code (bugfixed
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1267 from TI's original) implements just one buzzer ringing sound, consisting of
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1268 alternating 800 Hz and 900 Hz tones, using BU mode rather than PWT, and the
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1269 Mother currently has no plans to implement anything more for the buzzer
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1270 configuration.
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1271
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1272 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
1273
a39269dddca4 FC-handset-spec: firmware approach to audio routing and ringing
Mychaela Falconia <falcon@freecalypso.org>
parents: 55
diff changeset
1274 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
1275 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
1276 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
1277 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
1278 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
1279 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
1280 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
1281 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
1282
020e6428c248 FC-handset-spec: firmware approach to vibrating alert documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 56
diff changeset
1283 2.5. Vibrating alert
020e6428c248 FC-handset-spec: firmware approach to vibrating alert documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 56
diff changeset
1284
020e6428c248 FC-handset-spec: firmware approach to vibrating alert documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 56
diff changeset
1285 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
1286 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
1287 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
1288 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
1289 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
1290 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
1291 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
1292 firmware will "vibrate" virtually.
020e6428c248 FC-handset-spec: firmware approach to vibrating alert documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 56
diff changeset
1293
020e6428c248 FC-handset-spec: firmware approach to vibrating alert documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 56
diff changeset
1294 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
1295 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
1296 alert.
59
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1297
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1298 3. Venus development board
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1299
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1300 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
1301 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
1302 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
1303 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
1304
77
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1305 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
1306 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
1307 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
1308
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1309 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
1310 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
1311 being in scope for FC handset firmware.
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1312
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1313 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
1314 development board.
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1315
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1316 3.1. Build principle
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1317
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1318 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
1319 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
1320 (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
1321 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
1322
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1323 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
1324 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
1325 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
1326 firmware development platform for section 2.3.
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1327
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1328 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
1329 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
1330 supporting both buzzer and Melody E1 ringing.
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1331
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1332 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
1333 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
1334 would have been deemed non-essential otherwise:
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1335
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1336 * 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
1337 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
1338 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
1339 board when bringing it out is possible.
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1340
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1341 * 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
1342 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
1343
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1344 * 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
1345 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
1346 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
1347 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
1348 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
1349 both LEDs.
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1350
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1351 * 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
1352 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
1353 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
1354 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
1355 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
1356 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
1357 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
1358
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1359 3.2. Purpose and scope
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1360
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1361 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
1362 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
1363 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
1364 and purposes, use Caramel2 or FCDEV3B.
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1365
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1366 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
1367 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
1368 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
1369 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
1370 handset, so use Caramel2 or FCDEV3B.
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1371
77
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1372 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
1373
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1374 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
1375 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
1376 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
1377 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
1378 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
1379 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
1380 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
1381 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
1382 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
1383 handset motherboard:
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1384
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1385 * 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
1386 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
1387 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
1388
77
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1389 * 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
1390 backlight.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1391
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1392 * 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
1393 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
1394 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
1395 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
1396
77
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1397 * 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
1398 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
1399 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
1400
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1401 * 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
1402 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
1403
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1404 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
1405
3ead88660a4e FC-handset-spec: started Venus board description
Mychaela Falconia <falcon@freecalypso.org>
parents: 58
diff changeset
1406 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
1407 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
1408 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
1409 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
1410 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
1411 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
1412
77
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1413 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
1414 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
1415 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
1416 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
1417 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
1418 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
1419
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1420 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
1421
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1422 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
1423 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
1424 consisting of a USB mini-B interface connector, a charging on/off switch with
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1425 the charging circuit behind it, and the FT2232x subsystem of section 1.12.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1426
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1427 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
1428 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
1429 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
1430 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
1431 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
1432 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
1433 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
1434
77
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1435 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
1436 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
1437 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
1438 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
1439 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
1440 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
1441 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
1442 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
1443 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
1444 benefits:
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1445
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1446 * 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
1447 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
1448 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
1449 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
1450 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
1451
77
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1452 * 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
1453 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
1454 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
1455 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
1456 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
1457
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1458 * 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
1459 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
1460 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
1461 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
1462
77
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1463 * 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
1464 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
1465 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
1466 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
1467 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
1468 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
1469 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
1470 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
1471 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
1472 (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
1473 demo.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1474
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1475 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
1476
77
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1477 The FT2232x USB subsystem implemented on FC Venus will include the boot control
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1478 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
1479 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
1480 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
1481 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
1482 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
1483 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
1484 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
1485
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1486 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
1487 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
1488 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
1489 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
1490 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
1491 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
1492 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
1493
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1494 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
1495 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
1496 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
1497 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
1498 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
1499 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
1500 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
1501
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1502 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
1503
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1504 With the FT2232x USB subsystem integrated on the Venus board, this subsystem
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1505 will become the only way to access Calypso UARTs for initial bring-up of a
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1506 freshly populated board. Furthermore, our DUART28C-based boot control mechanism
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1507 will be the only way to trigger RPWON and nTESTRESET boot controls - there will
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1508 also be a PWON button (see section 3.6), but that one is intended for higher-
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1509 level end user functions after FC handset fw has been loaded and after all other
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1510 bring-up tasks are completed on each board. As a result of these factors, our
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1511 FT2232x USB subsystem becomes part of the critical path for board bring-up, and
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1512 it will in fact become the very first part to be brought up, before Calypso.
69
c6dafe9f3ac2 FC-handset-spec: BCI header change on Venus
Mychaela Falconia <falcon@freecalypso.org>
parents: 68
diff changeset
1513
77
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1514 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
1515 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
1516 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
1517
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1518 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
1519
77
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1520 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
1521 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
1522 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
1523 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
1524 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
1525 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
1526 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
1527 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
1528 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
1529 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
1530 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
1531 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
1532 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
1533 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
1534 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
1535 phones.
69
c6dafe9f3ac2 FC-handset-spec: BCI header change on Venus
Mychaela Falconia <falcon@freecalypso.org>
parents: 68
diff changeset
1536
77
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1537 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
1538 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
1539 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
1540 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
1541 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
1542 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
1543 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
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 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
1546
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1547 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
1548 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
1549 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
1550 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
1551 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
1552
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1553 3.5. LCD module and backlight
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1554
77
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1555 The LCD module on FC Venus will be Formike KWH020ST23-F01, the same LCD module
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1556 which we have settled on for the actual FC handset. As of 2021-09, we are in
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1557 the process of ordering 100 pcs of this LCD module (the payment has already been
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1558 made, and we are waiting for the shipment to clear customs), thus we are now
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1559 past the point of considering different candidate LCD modules. Our chosen
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1560 Formike LCD module is almost perfect for development boards such as FC Venus;
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1561 the only blemish is that in the absence of additional mechanical restraints, an
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1562 elastic force that originates somewhere in the area of the folded-under FPC tail
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1563 pushes the bottom of the module upward, away from the PCB, acting against both
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1564 gravity and adhesive forces. However, we have a planned workaround: we are
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1565 working with a local-to-us mechanical engineering company to produce a custom
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1566 retaining bracket; with the addition of this bracket, the mounting of our LCD
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1567 module is 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
1568
ed686a290f2d FC-handset-spec: LCD and backlight specification changes
Mychaela Falconia <falcon@freecalypso.org>
parents: 66
diff changeset
1569 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
1570 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
1571 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
1572 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
1573 the first fabricated Venus PCBs with components.
60
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1574
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1575 3.6. Keypad buttons
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1576
77
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1577 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
1578 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
1579 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
1580 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
1581 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
1582 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
1583 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
1584 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
1585 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
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 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
1588 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
1589 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
1590 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
1591 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
1592 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
1593 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
1594 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
1595 logical functions.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1596
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1597 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
1598 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
1599 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
1600 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
1601 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
1602 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
1603 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
1604
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1605 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
1606 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
1607 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
1608 our LCD.
60
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1609
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1610 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
1611 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
1612 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
1613 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
1614
77
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1615 3.6.1. No boot control buttons
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1616
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1617 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
1618 all 3 boot controls as in PWON, RPWON and nTESTRESET. However, now that we are
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1619 integrating the FT2232x USB subsystem of section 1.12 and the boot control
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1620 mechanism of section 1.12.3 as a non-removable part of the Venus board itself,
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1621 pushbutton switches for RPWON and RESET are being eliminated, leaving only PWON
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1622 in the "END" position in the main keypad.
da3bb12c2e6f FC-handset-spec: overhaul of Mother's vision for FC Venus board
Mychaela Falconia <falcon@freecalypso.org>
parents: 76
diff changeset
1623
60
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1624 3.7. Audio interfaces
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1625
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1626 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
1627 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
1628 interfaces will be as follows:
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1629
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1630 * 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
1631 and mic in the real handset) will be wired to a TRRS jack exactly like on
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1632 Caramel2.
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1633
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1634 * 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
1635 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
1636 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
1637
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1638 * 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
1639 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
1640 loudspeaker to be connected.
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1641
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1642 3.8. Magnetic buzzer
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1643
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1644 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
1645 (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
1646 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
1647 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
1648 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
1649 hardware provision.
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1650
f0d9a2cf15d2 FC-handset-spec: Venus peripherals documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 59
diff changeset
1651 3.9. LEDs instead of vibrator
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 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
1654 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
1655 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
1656 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
1657 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
1658
62
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1659 4. Motorola C139 port
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1660
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1661 4.1. Background information
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1662
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1663 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
1664
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1665 * Motorola C11x/12x
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1666 * Motorola C139/140
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1667 * Motorola C155/156
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1668 * Pirelli DP-L10
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1669 * Sony Ericsson J100
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1670
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1671 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
1672 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
1673 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
1674 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
1675 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
1676 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
1677 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
1678 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
1679
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1680 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
1681 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
1682 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
1683 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
1684 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
1685 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
1686 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
1687 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
1688 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
1689 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
1690 (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
1691 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
1692 96x64 pixel LCD.
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1693
63
4389cd2b9d02 FC-handset-spec: grammar fix
Mychaela Falconia <falcon@freecalypso.org>
parents: 62
diff changeset
1694 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
1695 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
1696 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
1697 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
1698 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
1699 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
1700 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
1701 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
1702 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
1703 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
1704 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
1705
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1706 4.2. Why C139?
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1707
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1708 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
1709 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
1710 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
1711 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
1712 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
1713 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
1714
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1715 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
1716 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
1717 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
1718 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
1719 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
1720 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
1721 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
1722 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
1723 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
1724 model.
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1725
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1726 4.3. How to make it happen
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1727
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1728 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
1729 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
1730 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
1731 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
1732 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
1733
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1734 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
1735 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
1736 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
1737 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
1738 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
1739 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
1740 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
1741 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
1742 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
1743 C139 hardware.
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1744
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1745 4.4. Functional scope limitations
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1746
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1747 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
1748 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
1749 do in that direction:
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1750
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1751 * 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
1752 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
1753 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
1754 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
1755 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
1756 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
1757
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1758 * No musical ringtones, just one extremely basic ringing sound - implementing
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1759 musical ringtones for the buzzer would be C139-specific work which is not
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1760 needed for the main goal of FC Libre Dumbphone, which will use Melody E1
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1761 ringing instead.
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1762
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1763 * No support for actual headsets in the headset jack! The headset jack on all
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1764 Mot C1xx phones serves a dual function, it is both an analog headset interface
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1765 and a digital interface for computer connection (UART at 2.8V logic levels),
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1766 and in FreeCalypso we absolutely require the computer interface function of
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1767 this jack - it is essential for development and debugging. Therefore, the
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1768 "ordinary end user" function of the headset jack is lost.
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1769
42d53bfbcca3 FC-handset-spec: Mot C139 idea documented
Mychaela Falconia <falcon@freecalypso.org>
parents: 61
diff changeset
1770 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
1771 "bare bones" phone - but the hope is that it would still be useful to some.