How can I make sure with Cube 2.1 (black), that the external magnetometer of the GPS puck is used as primary compass?
By default, in Mission Planner (1.3.66) I see all three compasses activated, for #1 “externally mounted” is checked and it is set as “Primary” compass. But in the status panel (yaw value) and on the map display (current heading, red line) I only see changes, when I turn the Cube itself. It also makes no difference, when I change the primary compass to Compass 2 or 3 or when I deactivate one or the other compasses alternately. Yaw / heading always change only when the Cube is turned.
From the mx/my/mz, mx2/my2/mz2 and mx3/my3/mz3 values I can see that mx/my/mz belong to the external magnetometer while the others change, when I move the Cube.
After playing around with these values and power cycling the Cube several times, the behavior is slightly different: Now, when turning the external compass (GPS puck), the yaw/heading turns very slowly (with a large lag) and I get complains about compass variance. When I turn the Cube, the yaw/heading still changes rapidly and I also get a compass variance error message. So now both compasses are fused somehow, but the internal one of the Cube still seems to have priority although in the configuration, Compass 1 is still set as primary compass.