OK, back to the plan; the next step is to get the compass readings in sync with the gyro readings for yaw as per my bus inspired plan:
I’m pretty impressed with this; the compass is measuring magnetic north pole orientation, where north to east clockwise rotation is positive; in contrast the gyro anti-clockwise rotation is positive following the right hand rule. Also the integrated gyro has no bounds on the yaw values it produces (±∞°), where as the magnetometer results (after some trig on the vector it outputs) is ±180°.
Note to self: gonna have to cancel the fusion when integrated gyro and compass yaw are significantly either side of zero. I do have one further concern: this test was run without props / ESCs powered up; I’m worried that once the motors are running, the magnetic force that makes the motors spin will completely ruin the brilliant synchronicity above. The next test for the plan will be to test GPS tracking over a 10m flight which, in passing, should also show the effect of the motors’ magnetism has on the compass readings.