Hello! We need help!
We noticed the strange problem: right after arming yaw suddenly became zero (see the video). Then we switched to auto mode and crashed. Before that we made several successfull flies with the same conditions. Thus this problem is not systematic.
Bin logs say that AHR2 data was correct all the time (lat, lng, alt, yaw). But ATT yaw was calculated with error. So the UAV has lost his home position and all the way tried to return to the wrong calculated position (it keeps the direction of the "home arrow" on the video).
We see that the ATT yaw jumps (green line) whereas AHR2 yaw behaves well (red line):
Copter took off in AUTO mode (it's not obvious by the picture above because of plot zoom). Later we switched to LOITER.
Full bin logs are attached.
Thanks for any help!