I noticed that the BlueBoat has three available compasses.
Currently, I’m only using the IST8308, and the MMC5883 and AK09915 are off.
I have a couple of questions:
Optimal compass configuration
What would be the optimal setup for the best results? Should I also enable the other two compasses, or is it better to keep only the best one active (which should be the IST8308)?
Compass calibration / Compass Learn
For the IST8308, I was able to perform a Full (onboard) calibration, but I couldn’t complete the Compass Learn procedure.
When I start Compass Learn and drive the vehicle around randomly, should I see a progressive increase of some value? Or after how long should it show “compassLearn: finished”? When I tried it, nothing seemed to change on the screen.
You’ll want to perform a Full onboard calibration on land, away from any large metal structures or high power electrical systems. If you’ve not routed any wires close to the Navigator, you should be able to get all three compass modules reporting in the green, or very close to it. If for some reason you’re not able to get a good calibration, you can disable that compass module so it doesn’t influence the overall EKF heading estimate in a bad way.
If you want to calibrate another way, you can drive aroudn as you did and process the log file with the MagFit tool - the parameters file it generates can be uploaded via Autopilot Parameters in BlueOS, and this will update your calibration values.
Hi @MatteoBucci -
I would suggest any compass module that is giving a wonky reading should be disabled. In BlueOS, on the compass calibration page under Vehicle Setup, you can see each compass’s contribution in the graph, with the light blue arrow indicating the fused output heading of the system. If all the arrows are in agreement, you’re all set - if one is much different than the others, it’s worth disabling or re-calibrating…