PM3 Wiki

alsa

Anonymous (anonymous@undisclosed.example.com) — 2026-04-18T09:29:24+00:00

Alsa Alsa is used for audio playback. NX does some initialization of audio: * amixer sset PCM 144 * other magic to get it actually working? People have had mixed results with Alsa initialization. One person only had success by running NX: "

barcode

Anonymous (anonymous@undisclosed.example.com) — 2026-02-22T17:44:34+00:00

Barcode Scanner Barcode scanner is either a Honeywell N5680 connected via serial, or a CODE CR8200. The nx application will apparently translate some Honeywell responses to Code responses, depending on hardware. The barcode scanner is on /dev/ttyS5

bin_list

Anonymous (anonymous@undisclosed.example.com) — 2026-02-26T04:41:08+00:00

Below is the result of ls /bin showing many of the provided utilities * NxExe * [ * [[ * aconnect * alsamixer * amidi * amixer * aplay * aplaymidi * arch * arecord * arecordmidi * aseqdump * aseqnet * base64 * basename

boot_process

Anonymous (anonymous@undisclosed.example.com) — 2026-02-26T06:02:48+00:00

Boot Process This boot process is universal to all PROXmobil3 units as best as I can surmise. 1. U-Boot starts up and loads the kernel from the rootFS microSD card. 2. The kernel loads systemd from /usr/lib/systemd/systemd. 3. systemd attempts to mount the

cvend

Anonymous (anonymous@undisclosed.example.com) — 2026-05-24T10:59:30+00:00

cVEND NFC Reader cVEND is the NFC reader on the bottom half of the PM3 The associated serial device appears to be at /dev/ttymxc3 @ 115200 8n1 in Linux. cVEND protocol notes Boot-up / initialization logic analyzer trace (open with the Saleae app):

debug_connector

Anonymous (anonymous@undisclosed.example.com) — 2026-01-27T23:15:06+00:00

moved to usb_service

device_tree

Anonymous (anonymous@undisclosed.example.com) — 2026-01-28T00:27:51+00:00

Device Tree Here's the device tree from /boot, converted back into text form: /dts-v1/; / { #address-cells = <0x01>; #size-cells = <0x01>; model = "PROXmobil3"; compatible = "tq,mba6b\0fsl,imx6dl"; chosen { }; aliases { ethernet0 = "/soc/aips-bus@02100000/ethernet@02188000"; can0 = "/soc/aips-bus@02000000/flexcan@02090000"; can1 = "/soc/aips-bus@02000000/flexcan@02094000"; gpio0 = "/soc/aips-bus@02000000/gpio@0209c000"; gpio1 = "/soc/aips-bus@02000000/gpio@020a0000"; gpi…

framebuffer

Anonymous (anonymous@undisclosed.example.com) — 2026-04-11T00:44:13+00:00

Framebuffer Graphics can be rendered using the linux framebuffer device, /dev/fb0. By default the framebuffer is 800×480 with a B8G8R8A8 pixel order. The framebuffer driver implements some special ioctls, its source is available here. Some notable ones: * MXCFB_WAIT_FOR_VSYNC

init-abtproxy

Anonymous (anonymous@undisclosed.example.com) — 2026-04-18T09:08:38+00:00

ABT Proxy This is a systemd service started automatically on boot. It executes /init/abtproxy/abtproxy, which in turn executes proxy_server (and restarts it on failure). In /init/abtproxy there are 4 JSON configuration files (config.json denylist.json keys.json labels.json

initseilnx

Anonymous (anonymous@undisclosed.example.com) — 2026-01-16T12:06:43+00:00

___ _ _ ___ _____ ____ _____ |_ _| \ | |_ _|_ _| / ___|| ____| | || \| || | | | \___ \| _| | || |\ || | | | ___) | |___ |___|_| \_|___| |_| |____/|_____| _ _ (_) |_ __ __ __ | | | '_ \\ \/ / | | | | | |> < |_|_|_| |_/_/\_\ OSELAS(R)-iLNX-01.02 / pm3-03.00 ptxdist-2019.03.1/2020-03-31T12:23:33+0200 ilnx login:

locations

Anonymous (anonymous@undisclosed.example.com) — 2026-05-13T21:06:08+00:00

List of Locations that use the PM3 city state country agency source Austin TX USA Capital Metro (CapMetro) kevin.wallace.seattle.wa.us/pm3 Seattle WA USA Sound Transit / King County Metro (ORCA)

main_board_overview

Anonymous (anonymous@undisclosed.example.com) — 2026-01-28T00:29:14+00:00

Main Board Overview This is the board that everything connects to. It is what the TQMa6x SOM plugs into, and contains all the circuitry needed to run it. It also contains the pic32. Chips In no particular order: part location ref description & notes

mountingplate

Anonymous (anonymous@undisclosed.example.com) — 2026-01-28T00:44:04+00:00

Mounting Plate As far as the software is concerned, this is the “mounting plate”: It is relatively uncommon, and most of them are believed to have been discarded during decommissioning. It takes 3V3, GND, I²C SCL/SDA, and USBD+/-, and passes the rest of the pins into the (snipped) cable. Over USB, it presents the SD card as a mass storage device, and over I²C, it presents a

nx

Anonymous (anonymous@undisclosed.example.com) — 2026-01-28T00:44:42+00:00

NX NX is the stock UI of the device. It interacts with: * framebuffer * alsa * cvend * barcode * pic32 * init-abtproxy It can be disabled with systemctl stop nx. If you do this, you almost certainly also want to NxExe watchdog 0 so that the PIC32 won't power the system off 60 seconds later. You may also want to

pcb

Anonymous (anonymous@undisclosed.example.com) — 2026-03-11T20:38:30+00:00

PCB images, pinouts Carrier board photos: Depopulated: X-ray (poorly colorized): Original X-ray (16-bit png): download here

pic32

Anonymous (anonymous@undisclosed.example.com) — 2026-05-03T01:16:09+00:00

PIC32 - the pic32 programming connector (labeled PIC32) matches the PICkit pinout exactly - readback protection is off :) firmware can be trivially extracted. iMX to PIC comms The watchdog communicates on /dev/ttymxc2 at 115200 8n1 Watchdog initialization and feeding:

printables

Anonymous (anonymous@undisclosed.example.com) — 2026-03-31T00:51:16+00:00

Somewhat relevant 3D prints PM3 desktop stand Download STL Tree supports recommended; any relatively rigid material should work.

projects

Anonymous (anonymous@undisclosed.example.com) — 2026-04-29T00:44:32+00:00

Projects This list is incomplete; you can help by expanding it. * : PCB to adapt rear D-Sub to 9-33V passive PoE + USB + I²C EEPROM + power button. * : PM3<->cVEND protocol analysis * trash can grab bag of stuff, currently mainly doom building for arm32 static. Pulls in

rust

Anonymous (anonymous@undisclosed.example.com) — 2026-04-11T00:46:45+00:00

Rust You can run rust on the pm3 by compiling a rust project for armv7-unknown-linux-gnueabihf like so: cross build --release --target armv7-unknown-linux-gnueabihf Because the pm3 uses an ancient version of glibc, you'll need to add a .cargo/config.toml

ssh

Anonymous (anonymous@undisclosed.example.com) — 2026-04-11T00:17:10+00:00

SSH You can get root ssh on the device relatively easily by remounting the filesystem read-write and modifying /etc/ssh/sshd_config to point to your keys. Placing something like the following in /autorun/95-enable-ssh.sh on the SD card should work (or in

start

Anonymous (anonymous@undisclosed.example.com) — 2026-04-21T02:40:52+00:00

PM3 Wiki This is a wiki for information about PROXmobil3 devices by INIT See About this wiki Email is working now! New accounts will need to confirm your email address. You can download all the public data for this wiki at Make some pages! Be bold! Have fun!

storage

Anonymous (anonymous@undisclosed.example.com) — 2026-02-22T03:50:31+00:00

Storage The PROXmobil3 has two 1GB microSDSC cards by default - one facing sideways, and one facing down. The sideways one contains the rootFS, and the downways one contains the initFS. rootFS The rootFS contains a minimal embedded install of PTXdist Linux 4.9, and is mounted

usb_service

Anonymous (anonymous@undisclosed.example.com) — 2026-01-28T00:27:02+00:00

USB Service Connector The debug connector on the bottom, labelled “USB Service” on the board, is a discontinued nonstandard USB device port made by Rosenberger under the name RoDI. The connector uses a magnet to hold the connector in place, which is also used to hold in a metal plug to protect it when not in use. A stronger magnet on the outside can be used to remove it. According to the system design document, this port can be used to access the internal SD cards without disassembling the devi…