I bought a raspberry pi and my plan is to with an arduino I have laying around to interface it with my 92 Bronco's OBDI Control module. I have seen OBD interfacing with arduino so I planned on having the arduino decode the information sent to it and then relay that info in raw numbers to the RPi which in turn will display it on a graphic display. The display will have every sensor reading the OBD has to offer. But as well as the information read outs I would have control of my sound system, door locks, windows, lights, and maybe the ignition through different options in the RPi's application. I was thinking that the control signals would be sent back to the Arduino which would trigger the necessary relays and what not to make the control happen (i.e. lock the doors). I have a few questions.
-Should I set out to make a custom OS? Or should I keep it simple with an application.
-What do I need to do to help with the Arduino and RPi voltage difference?
-Do I need an Arduino at all?
-Can an Arduino do all these things in a single program?(Probably can just a lot of if's and booleans)
-Would I need to use a Kernel Module to use the GPIO
-Are there and possible performance issues in the software because all that is happening.
I am experienced in Arduino but completely new to Raspberry Pi and novice at best in linux. I am going to start teaching myself more in depth C . And any other ideas you guys might have would be really great.
OH and the RPi will read the batteries Amps and shut it down if they get too low and the engine isn't running.