Didn't somebody make a board with several status (more than the usual three) LEDs for hooking it to the APM? And make a special branch of the firmware (Copter, as far as I remember) to control them? I cannot find it anywhere. I was about to do that same for ArduPlane to make pre-flight checkouts much easier to get done right. Maybe I can reuse something.
If somebody can point me the right way I would be grateful.
Kind regards, Soren