Hello,
Lately I’ve retrofited my car’s radio with a generic head unit running Anroid 12. Jansite S10 unit is using HiWorld CANbus interface through onboard serial port, so majority of car bus variables are available.
Now here’s my application: I’m commuting on a fairly short routes which is not enough to keep my car’s starter batter fully charged. In winter I have to use auxiliary charger from time to time to be sure it starts in the morning. I’ve built the charger under the hood and wired together with DEFA engine heating coil, so it starts smoothly IF i’ll plug it in 
What I’d like to do is get two entities of my car in HA: battery_voltage and alternator_power before engine shutdown. HA automation should turn on a socket and signal light on my driveway so I know I should plug my diesel in before I go home. This should happen only if the alternator was running full power before I’ve killed the engine or battery voltage is low (additional notification).
Now, has anyone of you been playing with such platform? Any chance to listen to serial comunication between the head unit and CAN Adapter?
P.S. and yes I know I can get this done easily and cheaply with ESP32 or something.