2- I can’t make a good compass calibration and I don’t understand why. I’ve tried with APM Planner and Mission Planner and there were the same issues: I still have an “error compass variance” even if I disable the compass2, values are too different.
The old and obsolete APM did use a different wiring than the Pixhawk. They are both I2c and serial for the compass and gps but the wiring is a bit different.
I failed to find a single reason to use an APM today (OCT 2018)
Cheers.
Henri