The cluster has arrived and it took me 'only' two hours to figure out that it wants +12 on three wires in order to start sending out CAN messages.
So, "BATTERY" + "IGN (START/RUN)" + "IGN (ACCY/RUN/START)" powered (and obviously GND) got me a constant flow of CAN messages. Here they are on the logic analyzer (that white box in the top-right corner)
Re: CAN bus: BMW instrument cluster
Posted: Fri Dec 13, 2013 12:58 pm
by AndreyB
With a hint from ChibiOS forum I have received my first CAN message! ARBID 0x613 is one of the cluster status messages. Big day for our CAN subsystem
Re: CAN bus: BMW instrument cluster
Posted: Sat Dec 14, 2013 4:06 am
by AndreyB
That's a miracle. This cluster has arrived yesterday and today I am controlling it?!
I hope one day we will control injectors via CAN.
Re: CAN bus: BMW instrument cluster
Posted: Sat Dec 14, 2013 4:22 am
by jedediah_frey
russian wrote:I hope one day we will control injectors via CAN.
Unfortunately CAN isn't deterministic (FlexRay will be) so CAN is best used for communication of non-realtime information.
Re: CAN bus: BMW instrument cluster
Posted: Sat Dec 14, 2013 5:22 pm
by AndreyB
Turned out e46 has a CAN message for speed, but the instrument cluster does not use it! Speedometer works via a PWM on a dedicated wire fed from some other block somewhere else. Tach an temperature is controlled by CAN. With 30 wires coming to the cluster it looks like the e46 is an intermediate technology mixing some CAN with some analog.
For example Mercedes W220 instrument cluster has only 11 wires connected to it - but no one has bothered to reverse-engineer the protocol yet.
Anyway, this was interesting experience and e46 cluster goes to eBay
