I just restored a Bang and Olufsen Beomaster 5000 (Yeah, 1985!), which connects to all of its components (CD, tape, phono) via a 7 pin DIN cable that contains audio signals as well as control signals. It has a single ‘Master Control Panel’ that controls the entire system via the amplifier, and coordinates signals via the DIN cable.
I can’t find a ton of documentation on this communication standard as they stopped using it in the 90’s, but got as far as this page: Decoding Datalink -
My question is this: If I wanted to interface the amplifier with Volumio, could I just treat the signal the same as an IR signal and then use LIRC to decode the signals? That way rather than trying to reverse engineer the standard I can just let LIRC learn the control signals. Does that work? I found voltage tolerance for the B&O signal, so my plan is just to wire it directly to the Raspberry Pi and see what signals are sent.