I have been flying my quad with APM2.5.2 (internal compass cut) and Arducopter 3.1.5 for many years without any problems all over the world
For some months, I often get a “bad compass health” message and cannot arm. Not always but almost always. So I bought a new compass and GPS combo (M8N+compass)
First thing I noticed that orientation with is incorrect. At roll 180°, all directions seem to be correct. So I did two flights. They worked but in LOITER it was flying in a cicle even at 13 sats and HDop of 2 . At the third flight I got “bad compass health” again and I could not arm.
So I flashed the newest firmware possible (v3.2.1) but still “bad compass health”. I attached some screenshots from the last flight with new GPS and compass without “bad compass health”.
What could be the problem? Compass is calibrated and orientation seem to be correct.
I know there are already some threads about this topic and APM hardware is no longer supported but maybe there is an easy way to fix it.
Edit: Today I tried another flight and there was no Bad Compass Health. Also Loiter worked fine! Is it possible that it is dependent on the temperature?