Magnetic interference warning when arms are folded?

kodiak1120 · Dec 16, 2016

I was about to calibrate the IMU after a firmware update, so I had the arms folded and turned it on. When I did, I immediately got a warning about magnetic interference and was instructed to calibrate the compass, which I did. When I unfolded the arms, the warning went away. I tried again later, and got the same result. It seems it's the front left arm that is causing the interference when folded. All other and can be folded without a problem. Anyone else notice this? Could it be the magnet in the motor?

makg · Dec 16, 2016

That's normal, you're right about the magnets in the brushless motors causing interference.

It should never need the compass with the arms stowed, however the warning to recalibrate is annoying. I don't think there are sensors in the arms to know if they are out or in though.

Alex Baxter · Dec 17, 2016

NEVER calibrate the compass with the arms folded, if you've done that, then re-calibrate the compass following the DJI instructions, otherwise you're a crash waiting to happen..

kodiak1120 · Dec 17, 2016

I was calibrating the IMU when it was doing this, not the compass. I did subsequently calibrate the compass, but I unfolded the arms first. I just wasn't sure if the magnetic interference would mess up the IMU calibration since that has to be done with the arms folded.

Strafe1 · Feb 5, 2017

this is happening to me so I am checking how to move forward.....

Alex Baxter · Feb 5, 2017

Strafe1 said:
this is happening to me so I am checking how to move forward.....

If you're calibrating the IMU correctly, you'll get compass errors when you switch it on with the arms folded,ignore these warnings during the IMU calibration. Only if you get compass errors with the arms unfolded when in a flying environment do you need to worry, other than the known issues with sport mode bringing up errors, plenty of posts on this.

Strafe1 · Feb 5, 2017

Thank you, Alex. I searched as many posts as I could find and I could not find this information!

looopson · May 14, 2017

kodiak1120 said:
I was about to calibrate the IMU after a firmware update, so I had the arms folded and turned it on. When I did, I immediately got a warning about magnetic interference and was instructed to calibrate the compass, which I did. When I unfolded the arms, the warning went away. I tried again later, and got the same result. It seems it's the front left arm that is causing the interference when folded. All other and can be folded without a problem. Anyone else notice this? Could it be the magnet in the motor?

Did you successfully calibrate the IMU with the arms folded, simply ignoring the "compass error" messages? I'm dealing with the same issue and afraid to proceed with the calibration with these "compass error/magnetic interference" messages.

msinger · May 14, 2017

Magnetic interference does not affect the IMU. Just ignore those messages and carry on.

Strafe1 · May 14, 2017

Definitely ignore them. But the DJI video should have addressed this in the how-to video, IMO. RC warnings shouldn't be ignored and it would be nice to be told that this warning is expected. Thanks to this forum, it was clarified for me.