Showing posts from October, 2012

Moving in a different direction

I recently purchased a 1995 Jaguar Sovereign (you might know it as a Jaguar XJ, but the Sovereign spec doesn't actually wear an XJ badge anywhere). It has a CD changer in the boot and a radio/cassette in the dash. The radio is rumoured to only accept a specific model of CD changer while using the Alpine M-BUS protocol. What I want to do is build an M-BUS to UART adaptor out of an Arduino, or a TI Stellaris Launchpad (mine's on back order) and use that to control a Raspberry Pi running an MP3 playback daemon. Six disc buttons gives you six playlists and the skip forwards / backwards should be usable too.

While I wait for the Launchpad, I've been putting my Arduino to use trying to probe the data pins, without too much success I might add. What I have managed to do is:
Build a 5V switch-mode power supply to turn the car's 12V (or actually 10V to 14V) supply into something the Arduino (and a Raspberry Pi) can handle. I'm using the LM2576 of which I picked up three off …