I am using a Pixhawk and an external GPS/Compass Unit and I come across the following problems:
After calibrating both the internal and the external compass with the Onboard Calibration the orientation shown in the Flight Data panel was correct but it started rotating after a few seconds and ended up with an offset. The offset would get greater very slowly with time.
The same thing happens with either the internal compass selected or unselected. The external compass is always selected as the primary one.
The Flight Data panel responds to the internal one only no matter what the primary compass is selected. However it does show the error Compass Variance when I only move the external one.
Live Calibration is not available
The GPS/Compass module I am using is GYGPSV5-NEO 7M M8N and I am only using the Compass (I have a separate chip for GPS) which is connected with an I2C connector (only the two middle ones).
Any ideas as to why this would happen and any comments on how to fix it? Also why does the flight data panel only responds to the internal one?
Thank you for your help!