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

4 Likes

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

3 Likes

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

Awesome work!
This looks like it would be a lot more useful in a car application than the Pi-hat (which feels to me more like a development tool).

I also messaged you @rhys_m using the contact form, hopefully that went through, I am very interested in learning how you sourced these most chips and their relevant interfacing docs. I’m more than happy to support your development and buy the PI hat, but ideally I’d want to implement most in my own design (ideally with an esp32 series chip)

Hi,

I have responded via email!

Thanks

Rhys

what do you think when the project is ready to purchase? :slight_smile:

Hi, I’m currently still finishing off the drivers, I’ll then thoroughly test in a car environment, then finalise the board, I am guessing a couple of months minimum but could well be longer!

1 Like

Big update on this, on multiple fronts! I’ve managed to completely replace the touchscreen in my test bench with a PiMost, there’s a bunch of communication that had to be reverse engineered, but by using a PiMost and hijacking addresses it is do-able, the master now starts up healthy and treats the PiMost as though it is the OEM screen!Second part is to do with the drivers, these are probably 90% of the way there now for the USB version, audio seems good, messaging etc is great.Third part is by replacing the screen and figuring out the propriety source control that JLR have implemented, I can completely control sources, and even reuse the old ipod module addresses to stream audio from the PiMost in an OEM fashion.

In the below video there is no screen in the MOST network, the PiMost-USB is handling all those requests directly from my mac. The PiMost also appears as a USB sound card and you can see the source switching works direct from OSX too!PiMost Audio switch and USB audio

Audio is super quiet apologies!

@InfinityMod I have a friend that has a 1 series 2013 that I am going to test on, he is in the process of ordering an android touchscreen for it, I will let you know how it goes.

1 Like