MOST USB standalone project

Hi All,

Going to keep an updated thread here on the progress of the standalone MOST module. I’ve mapped out the functionality for a starter

  • USB CDC connection that sends MOST messages that can be translated to the same format as SocketMost to allow it to run in “client mode” so the host has full control
  • Device also appears as a USB soundcard with mic input and also audio out
  • Option to configure amplifier and microphone address, then when the sound card either receives audio, or the microphone is used, it auto connects amplifier/microphone

A few thoughts on extra functionality

  • opto output that can be used to switch power to a pi
  • Ability to write your own Fblocks with implemented fkts (would allow replacement of any device on the current MOST netowork once fkt data responses are known)
  • Can channels, the stm32 chip in use has two can channels, not sure if enough endpoints/bandwidth to allow these to run as slcan over usb

As an update, the first rough prototype board has been delivered, and alot of the messaging functionality is now complete


Small update, preproduction board arrived yesterday complete with flashy LEDs! This now has a 3.5A buck converter and usb output to power the pi.

I am in the process of implementing, but it will look something like the below

  • most signal comes on, Stm32 switches power to the pi
  • pi turns on, Stm32 detects voltage on the vbus for the serial port/sound card
  • MOST signal goes off, PiMost sends shutdown command via serial, driver receives it and shuts down the pi
  • vbus turns off once pi is powered down
  • Stm32 switches off power to the pi
  • Stm32 goes to sleep


It’s been a while since I’ve dropped by to check in on this project. This looks pretty cool! Have you considered using one of the optical+electrical connectors like a 2+12? This would allow for a much cleaner installation. Especially if all commonly used connectors can be placed on one edge of the board.

Not a bad shout, only issue is they are quite a bit harder to get hold of and quite far from standard. The board here is just a complete prototype one, I’ve got some preproduction ones going now which are much more compact and use 3.5mm pluggable power connectors