"Yes, if you are interested. I discuss this problem here.
I think that it is tricky question, but can not figure out what is wrong..."

"Yes, for now i use Mahony quaternion filter to estimate the orientation of my sensor relative to the global coordinate frame. To get tilt-compensated magnetometer readings i extract euler angles from my quaternion and then use them to level the…"

"Hello. I think that i have the same problem. I try to implement full tilt-compensation for magnetometer readings because the scheme with roll and pitch angles works pretty well only when your device is not turned upside down.
I tried to use…"