I’ve been buiding multirotors from various sizes since 2019. I noticed that, independent of ArduCopter version, from times to times my drones starts randomly to present pre-arm checks regarding the magnetic field and inconsistent compasses (despite adopting compass mounting good practices). I have always performed my compasses calibrations in Mission Planner, but I would like to know if someone reccomends other GCS to perform it. Additionaly, I would like to understand better how the magnetic declination is considered regarding compass calibration.
PS: I am from Brazil and here we have one of the weakest magnetic fields on Earth, so could this explain the need for constant compass recalibrations?
For an initial calibration that’s fine. I would then use Magfit for final calibration of offsets and compass motor interference coefficients.
Declination is really just a static value based on geo location as the difference between magnetic and true north. It’s not really a consideration for the offsets generated during calibration.
So it is a kind of data that comes with GPS information and is took in account in realtime execution of ArduCopter Software?
Nice. Thanks for the tip. For some larger drones I used sometimes the compass-motors calibration via Mission Planner, it is worse than using this Magfit application?
Yes, exactly. There is a world model database of declination stored.
I can’t say for sure which is better as I never used the MP method so I can’t compare. But the Magfit method sure is a lot easier to implement and no issues so far.
Nice! Thanks for the information @dkemxr!