TESTED AND VERIFIED WORKING ON 44.1KHZ!!
PLEASE ENSURE YOU UNDERSTAND THE CURRENT SUPPORT AVAILABLE AROUND MOST BUS. IT IS PRETTY MUCH ZERO, THIS HAT ALLOWS COMMUNICATION ON MOST25, DRIVERS ARE AT A VERY EARLY STAGE, AND RESOURCES ONLINE FOR MOST ARE PRETTY MINIMAL. IN ITS CURRENT STATE IT IS SUITED FOR PEOPLE WHO ARE CONFIDENT ENOUGH WITH PROGRAMMING TO JOIN THE ADVENTURE OF EXPLORING MOST. IT’S NOT RECOMMENDED FOR PEOPLE WITH LOW PROGRAMMING KNOWLEDGE.
This is a fully featured MOST bus hat for a Raspberry Pi that I have created and designed. I believe it is the first of it’s kind so it’s important that it’s clear what it does, what it can do, and what it doesn’t do!
– OS8104AAQ chip
– USB power input
– Timer to hard switch power off 30 seconds after no most activity
– 1 Canbus channel
– 120Ohm terminating resistor via jumper
– MOST25 Transceiver
– Auxiliary 5v for screen/fan etc
What it does
Interfaces for MOST25 (tested on JLR at 48khz and BMW at 44.1khz)
I have made an early BETA driver for the OS8014 chip written in NodeJs. This is created with the idea of interfacing with any language, so transmits raw Most messages to a unix socket, which can then be consumed via any language.
It has one CAN channel with optional 120 Ohm resistor. It uses an MCP2515 and MCP2562 for this.
Allows audio to be sent out of the pi via i2s to the fibre network, and also fibre to pi as audio input. This is handled by the chips own i2s clock, so you don’t have to deal with the awful one in the Pi! However this needs implenting on the application side, I have acheived this and will share how it was done.
What it doesn’t do
It doesn’t give you an instant representation of your MOST network. The network as a whole is quite complex, but also much more user friendly once you get into it than Canbus is. Devices have notification matrixes, so when you request to be notified, the MostPi will get sent a message direct, this works well on JLR but mileage may vary on other brands! I will make available all my JLR works, where you can see complete control of the Most network, displaying and controlling radio data, microphone, cd player etc etc. Whilst some of these use the standard Most Cooperation functions, so should be somewhat compatible with all manufacturers, each manufacturer can decide to implement completely custom functions instead, so zero guarantees!
It doesn’t have linux kernel drivers like canbus does, this is on the roadmap, but no timeline!
What it can do
Pretty loaded question! It can do whatever you would like it to do when it comes to Most integration, see some of my videos for some examples.
USB C 5v Power input
It has headers for 5v to be supplied with out USB-C
Handles Pi Startup/Shutdown, on Most activity it switches on power to the Pi, when activity is lost a GPIO input goes low on the Pi which can then trigger a shutdown, 30 seconds later it then completely cuts power to the Pi.
This is a first for Most so anyone looking to purchase need to be aware of this. I have made the hardware available and I am working alot on the software side, however I can only really experiment in the realms of Jaguar Landrover, (almost all functions have been tested now on a BMW e90). So if you are confident at programming, have done a fair amount of canbus stuff, and looking to integrate the other 50% of your car, this may well be the product for you! The more people looking into the software side, the better it will be for the community as a whole! Final Notes, this is a development board, whilst it has been tested and used extensively on both my vehicles, use at your own risk, I take no responsibility for any potential damage incurred from use/misuse of this product.