EKF3 IMU1 MAG0 yaw re-aligned and compass

ArduRover ArduBoat
1

Hi, im using ardupilot in a rc boat that is running 4.2.3/Pix 6C mini along with a Holybro RM3100 compass. In the water, and sometimes when moving the boat it occasionally pops up with EKF3 IMU1 MAG0 ground mag anomaly, yaw re-aligned error. This then makes the compass be incorrect. Normally a reboot can sort this out. The Compass is not near any magnetic field (used an analogue comapss to check for interference), but what could cause this? Any settings that i could look at to stop this recalibration?

2

Yes, do a MAGFit calibration using the MAGFit Webtool

1 Like
3

ok, thanks. I’ll give this a go.

4

The mag anomaly message normally means that the compass IS suffering from external interference. A magfit using the web tools is certainly a good starting point but a physical solution may be required. E.g. move the compass further from any sources of interference and it’s also probably a good idea to disable the internal compass (the one inside the autopilot)

5

Thanks Randy. I will try and move all my electronics to get rid of as much interferece as i can. Im aware of Large vehicle magcal and the ability to do onboard calibration with a handset switch (171),however, as this is a boat in the water and only cares about the azimuth orientation, is there not an reduced onboard calibration that can do just this azimuth?

6

Hi @Resny73,

For boats I sometimes use the COMPASS_LEARN = 3 method which is on the advanced compass calibration page.

So you can set the parameter, then drive the boat around in a few circles and it should come up with good offsets.

The magfit web tool can also be used if you’ve got a log of the vehicle driving around in circles.