I have a custom build that I'm still working on and tuning, but it is in a very flyable state currently. Using ArduPilot 2.5 board and running 3.1 software. I used Autotune feature to dial it in pretty tight.
One thing that I've noticed as of recently is that it would randomly switch direction 180 degrees in mid-flight! In other words - it takes off, flies fine for a while (in stabilize + simple mode) and then all of a sudden forward becomes backwards and left becomes right. WTF?!
My compassmot is around 55%, a little high but still OK.
I can't figure this one out for the life of me. Has anyone had a similar issue?