(Video) Roll angle readings at rest - is this normal?

Hi all,

I have the ArduPilot firmware installed on a new Pixhawk 2 with Here GPS (M8N), powered by computer USB. The GPS is fixed above the Pixhawk via a 20cm mast and has a GPS fix.

With the device sitting on my desk, completely flat and still, this is the live roll angle readouts i get in Mission Planner. It fluctuates by 0.5 degrees peak-to-peak. (Big jump at 0:40 in video)

Is this normal? Anyone get a flat consistent reading?

Thanks in advance

I’ve tested an stand-alone Arduino+MPU6050 (6DOF accel/gyro) which has built in orientation filter/algorithms, versus the Pixhawk 2 and the latest ArduPilot with and without the GPS connected. The tests were with devices on flat bench, untouched for 20-30mins.

I’m assuming when the GPS is detected, the algorithm shifts more reliance onto it, and less reliance on built in accelerometers for correct gyro drift? GPS at rest still shows very slight changes in speed, maybe that is the cause of why it fluctuates more.

Anybody else see similar results?