E&C Bus... Anybody?

New hack on an old bus.. E&C.

I'd like to make an aux adapter for all of us with in dash CD UNO head units in our 90s era GM cars. As some of you know, the UNO single CD player can't control a changer and the aux adapters emulate a changer. So no go.

I hacked an adapter out of a remote cassette deck a few years ago and now I plan on hacking the E&C protocol that controls that... Emulate the cassette deck via AVR/arduino.

Anybody out there have anything on E&C?

So far this is what I have to go on: http://pangea.stanford.edu/~schmitt/e_and_c_bus/