[mythtv] Serial Port (RS-232C) control of high end Sony units

[Kevin Elliott]

I want to make use of my high-end Sony ES receiver and dvd changer
with MythTV, so I'm beginning to create code that will utilize
them so the receiver can be controlled from MythTV using the RS-232C
control ports, and the 400
disc dvd changer can be used in MythMusic and MythDVD. Ofcourse,
I first need to figure out the protocol that Sony uses. I've been
searching for atleast 10 months for the specifications of the
protocol, and can't find anything. Sony keeps that private for
commercial products that control the units.

Unfortunately, the commercial control units aren't cheap. Control-S
and Control-AII ports are most often unidirectional and don't provide
a bidirectional flow of information like the RS-232C ports do. So
the only way to get cd and dvd data, or receiver status information
is over the serial port.

Does anyone have any information on Sony's RS-232C control protocol?
(not the rs-232 interface specification)

Once I find this out, I can finish up the code (abstracted) so that
other devices could be controlled as well. 

The guys at www.cinemaronline.com have seemed to figure out the
protocol for my Sony CX777ES 400 disc changer and wrote some windows
code to interface to it and I've emailed them about it. Hopefully
they'll be kind enough to lend me the information, otherwise,
it's back to the drawing board.

Regards,

Kevin Elliott
kevin at phunc.com