Let's get down to details in here.
Volvo V70II T5 (aka The beast):
There are basically 3 communication networks that one can mess with:
- High-speed CAN-bus (All important thing are here. Like engine, transmission, ABS... better not to mess with this network)
- Low-speed CAN-bus (Mainly not so dangerous features sit here like power windows, locks, interior lights, AC and so on.)
- MELBUS (Radio aka Head Unit and GPS navigation sits here. Really nice, simple and safe network to hack.)
Hacking into MELBUS:
I originally used Arduino Nano (okay... do your booooos now) but then I switched to STM32F103 because running 12MHz bus onto 16MHz Atmega is just... let's not say stupid but rather awful idea. Well it worked, yes but reliability? You would rather spend all day getting FSO Polonez to run than this. Arduino is big no no for MELBUS. However after switching to STM32F103 everything started working just fine. Now i can emulate CD changer, read buttons that are pressed on HU and have HU think that there is actually CD changer. I'm getting ready for emulation of more devices.