Magnetometer vs magnets

Hello all,

I raised a propblem with my magnetometer earlier and have now found the propblem but not the solution,

basicly i have changed airframes on my hex i used to have a 12" gap between props i have now moved the motors closer so now have a 4" gap between props, since i have done this my magnetometer is now out by about 45 degrees , this is with no power to the main motors so the conclusion must be the magnets in the motors are affecting the magnetometer, does anyone know how to get around this? as obviously the way it stands i can do no gps positioning.

 

regards

 

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  • Marc, did you have the chance to upload recent firmware from the planner?

    If no, please give it a try then:

    Reset all of you parameters.

    Calibrate radio and configure as usual.

    Calibrate your mag without turning on the motors away from any metal or source of magnetic interference (you can now set the offsets in the left side of the configurator...) 

    Fly in stabilize mode for a while with mag enabled (and declination configured)... like a few batteries.

    In ths time try to face the copter in a 360° pattern.

    This has to be done in a magnetic interference free environment.

    The best would be to fly at least for 8/10 minutes to allow automatic compass calibration to converge correctly.

    Then test away from any big computer, heater (yes my fixed home heater is connected to house ground and is a huge magnetic interference!) and let us know.

    What you have done is  account for the magnetic interference of the motors during flight, something you cannot do in static calibration.

    You must reset all of your parameters before this, otherwise you will keep your old values in and probably all this will not work.

    Hope this helps,

    Emile

  • Marc, Ensure you do not have any magnetic parts trays, or anything magnetic on your workbench, they will effect your sensor if too close!  I had that happen to me for a while, it was very confusing till I moved it!

  • Hello Marc.

    What happens if you recalibrate the mag?

    You could do this by disabling the compass, re-enable it, arm without props or with a separate BEC and rotate the hexa on all three axes in all directions. When done disarm so the new offsets will be saved.

    Beware that after 25 secs if no throttle is given it will disarm automatically, that's why you should use a bec or no props.

    Certainly because you actually changed your frame (shorter arms) the influence of the 6 motors will modify your heading.

    Please let us know!

    Emile

  • Developer

    Hello Marc, we are discussing it on the dev list, you're not the only one to be afflicted by this problem.
    It 'obvious that first of all your hardware should be sought in the causes that could give rise to these problems, but it is said that you can still easily recover from.
    We are thinking of a solution to the problem, I hope by software.
    Please you may bring your complete hardware configuration?
    Also some photos would be appreciated, especially the installation of the APM.

    Bests

    Marco

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