FreeCalypso > hg > fc-tourmaline

annotate doc/Voice-pseudo-modem @ 297:8dfdf88d632f

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
BUZM SWE initial implementation
author Mychaela Falconia <falcon@freecalypso.org>
date Tue, 29 Mar 2022 03:45:41 +0000
parents a62e5bf88434
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
50
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1 Back when TI's TCS211 fw existed in the traditional world of phone handset and
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
2 cellular modem manufacturers, there were only two principal classes of target
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
3 devices for it: handsets and modems. The former have local UI hardware (LCDs
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
4 and keypads) and run firmware that works with this UI hw, the latter have no
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
5 such hw and run firmware that expects to be controlled by an external host via
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
6 AT commands.
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
7
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
8 But the peculiar circumstances under which our FreeCalypso family of projects
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
9 operates give rise to a third possibility: what happens if one were to run
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
10 non-UI-capable firmware that expects control via AT commands on a hardware
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
11 target device that was originally designed to be an end user phone handset, in
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
12 our case either Motorola C1xx or Pirelli DP-L10? The result is what I call a
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
13 voice pseudo-modem (VPM): the phone's LCD stays dark, the buttons do nothing
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
14 and the device expects to be controlled via AT commands as if it were a modem
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
15 like the one in GTA01/02 smartphones, but there is no practically usable way to
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
16 make use of any data services, only voice and SMS, hence my VPM term.
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
17
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
18 It needs to be noted clearly that the VPM hack described in this article is NOT
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
19 a substitute for proper modem hardware - if your area of interest is Standard
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
20 Modem functionality (the full set of GSM and GPRS services accessed via AT
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
21 commands), then you need a proper hardware platform for it, either FCDEV3B or
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
22 Caramel2. However, support for VPM operation in FreeCalypso exists for the
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
23 following purposes:
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
24
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
25 * On some hw targets the VPM configuration can be an intermediate stepping stone
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
26 toward potential future UI-enabled firmware - this situation holds on the
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
27 C139.
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
28
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
29 * Being able to run FreeCalypso fw in the VPM configuration on Mot C1xx hw that
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
30 many people already have and that may still be readily and cheaply available
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
31 makes our firmware accessible to those who are not able to buy new FreeCalypso
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
32 hardware.
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
33
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
34 * If you have a Pirelli DP-L10 phone (now very rare and hard to get, but were
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
35 readily available in early 2013 when I started FreeCalypso): while there is
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
36 unfortunately very little chance of being able to turn it into a practically
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
37 usable Libre Dumbphone with FreeCalypso (the unwanted extra chips sans docs
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
38 which we don't know how to power down are a killer), running FreeCalypso fw
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
39 on the Pirelli in the VPM configuration is so easy and convenient that I do
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
40 it all the time during development and testing.
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
41
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
42 Playing with FreeCalypso VPM on C1xx phones
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
43 ===========================================
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
44
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
45 If a Mot C1xx phone is flashed with a FreeCalypso firmware image in the VPM
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
46 configuration, it will behave as follows:
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
47
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
48 * The LCD will remain dark and the buttons will do nothing no matter what.
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
49
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
50 * If you plug in Motorola's charging adapter (it's a regulated 5 VDC power
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
51 source, but with a non-USB connector) and you had properly installed the
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
52 charging config file when creating the aftermarket FFS for FreeCalypso, the
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
53 battery will charge. When you unplug the charging adapter, if there is no
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
54 host computer running FC host program rvinterf connected to the phone
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
55 serially, the phone will power off some 15 to 20 s after the charger unplug.
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
56
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
57 * If you press the power button while the phone is off, even momentarily, the
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
58 phone will power on and boot (with nothing on the LCD as usual), but if the
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
59 headset jack serial port is not connected to a computer running rvinterf, the
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
60 firmware will execute a power-off after at most 20 s.
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
61
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
62 * In order to make the phone-turned-VPM do anything useful, you will need to
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
63 connect the headset jack serial port to a host computer running FC host tools,
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
64 run rvinterf to keep the phone alive (keep it from automatically powering
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
65 off), and use FC host utility fc-shell to issue AT commands to it over the
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
66 RVTMUX channel managed by rvinterf.
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
67
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
68 * The phone will remain on (i.e., the fw won't execute an automatic power-off)
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
69 for as long as there is either a charging power adapter plugged in or a
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
70 connected host computer running rvinterf - if there is no charging power,
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
71 the fw will send periodic keepalive queries to check for the presence of a
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
72 connected rvinterf process.
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
73
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
74 Playing with FreeCalypso VPM on a Pirelli DP-L10
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
75 ================================================
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
76
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
77 There are two ways in which one can play with FC VPM firmware on a Pirelli:
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
78
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
79 * FC VPM fw can be flashed into the phone just like on Mot C1xx. To make this
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
80 approach sensible, you will also need to craft and install a charging config
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
81 file that will cause our FCHG driver to initiate the charging process
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
82 automatically when the battery voltage falls below some sensible threshold,
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
83 without requiring manual charging start via AT@CHG=1. In this case the
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
84 reflashed phone will behave like C1xx in the previous section, except that
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
85 the charging power source and the host computer connection are one and the
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
86 same in the case of Pirelli's USB.
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
87
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
88 * The other approach is to keep Pirelli's original fw in the flash, let the
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
89 phone function normally when not in the middle of a FreeCalypso VPM session,
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
90 and load our FC VPM fw into RAM via fc-xram, making use of this phone's huge
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
91 RAM that can hold an entire functional fw image without flashing. This is
a62e5bf88434 first round of documentation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
92 the Mother's preferred method.