Dear all:

Can some one help point out where my problem is? I have completed 6 point sensor calibration, autotune , PID, .. etc. In the Attitude/ filter setting, I use INSoutdoor for Attitude and INS for Navigation. The PH I did was always good at begining, but later my quad copter will start rotating certain degree, therefore I found the quad had turned into face the true North. This is really confused me.

Could this be any problem caused by my Neo-M7N gps? I am sure most of the time it has 8~10 satellites locked, so I am not sure if it is wherther or not the problem due to satellite number.

In the system / vtolPathFollowerSetting / YawMode, I selected AxisLock. It should lock my quad copter in the direction where I want.

Can someone help or teach me to solve the problem.

Thanks in advance...