Thursday, January 27, 2011

E and C Cassette Deck emulation

I got it working, I'll post some arduino sketches this weekend.

Have one that emulates and one I have been using as an E&C scanner.

Next step is PCB design. Might port the design from Atmega328/Arduino to Attiny85 or something.

Not bad, 4 days from getting the cassette deck to working emulation!

Friday, January 21, 2011

E&C Head Unit logs

So far, everything I have seen from a 97 CD UNO Chevy Camaro head unit on the E&C Bus. Protocol looks pretty easy to replicate and I think I should have no issues emulating a cassette deck.


Radio On:
1100001011111110010101
Radio Off:
1100001011111110000100

User keypress or sync or something. Happens after most user key presses:
111001101111                                                                

Cassette Deck Poll?:
1110011100000100                       

CD Transition:
111001101110001101
1100001011111110010101 (Confirm this?)
111001101110001101

Cold Start. 12V applied
1101010100                                                                  
111001101111                                                                 
111001101111                                                                
1100001011111111                                                            
1110011100000100                       
1110011100000100                       
1110011100000100                       
11100111000100                         
1100001011111110000100                 
1110011100000100                       
111001101111

Powering Radio on
111001101111
1100001011111110010101
111001101111

Powering Radio Off
111001101111
1100001011111110000100

Most key press events
111001101111


Aux with no CD (Think this is the look for tape deck command. Will confirm when I get one)
1110011100000100

Inserting a CD
111001101110001101
1100001011111110010101
111001101110001101

Ejecting CD
111001101111

Remove Ignition
111001101111
11000010111111100100

Power on by Ignition
1110011100000100
111001101111
1100001011111110010101
111001101111

Thursday, January 20, 2011

E and C bus decoding progress

So far so good. I have the arduino reading E&C. I have observed about 5 or 6 messages. Simple stuff so far. Waiting for the cassette deck so I can progress further.

My data seems to match the link below, at least for radio on and off events.

I will document my progress once I get some ambition. I have a proof of concept and some working arduino code to show for my efforts tonight and that's more than I expected.

Wednesday, January 19, 2011

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/