So I want to build a programmable flasher relay for my 97' BMW 328is. There are 2 things I want it to be able to do. The first is I would like to switch all of my turn signals to LED bulbs which they do not make a correct flasher relay for this already. The second reason is I'd like to add the "One Touch Turn Signal" feature like a modern BMW has for switching lanes (basically you click the lever half way and let go and the signal blinks 3 times)
I would like this to be integrated inside of a gutted factory style relay housing, it's a double height relay so it should have plenty of room. I would like to build it robust enough to handle both halogen and LED bulbs. It will probably need to be able to handle up to 15 amps. Seems that if I had 2 small relays controlled by some programmable device with several inputs that this would not be too difficult.
6 inputs:
12V constant
Ground
Left Signal
Right Signal
Hazard
Crash Module (turns hazards on if airbags are deployed)
2 Outputs:
Left Side
Right Side
Each side outputs to 4 lights, 2 are the main "high amp" signal bulbs and 2 are small bulbs that would probably draw less then half an amp combined in the instrument cluster and a side marker. Realistically each side should draw less then 5 amps but the main fuse for the system is a 15 amp fuse (granted that's because if you have the hazards on it will turn all of them on at once).
I don't believe this is a very complicated project and probably a very easy thing to program for a newbie like myself. I believe I could likely use an Arduino Micro for this rather easily? I just don't really know what's best to convert the outputs from something like the Micro to a high amp circuit. A typical relay will likely be too large but I don't know much about Solid State Relays.
Any and all help will be greatly appreciated!