Interesting information.

I just replied to another thread about a test I just did with an iPhone XR and a Samsung GS9 using a strong magnet from an old hard drive, I was unable to make any difference in compass heading on either phone, save 1 degree difference on the samsung. Although not conclusive as that is all the devices I have access too, I have to think either poor quality device ingress insulation in some devices or the interference is something different that magnetic.

JodyB Posted at 12-23 08:05
I just replied to another thread about a test I just did with an iPhone XR and a Samsung GS9 using a strong magnet from an old hard drive, I was unable to make any difference in compass heading on either phone, save 1 degree difference on the samsung. Although not conclusive as that is all the devices I have access too, I have to think either poor quality device ingress insulation in some devices or the interference is something different that magnetic.

I just read that Phones and tablets either use a magnetometer compass that uses the earth's magnetic field, or an electronic compass that uses GPS and accelerators, or a combination.  

Minnesota Posted at 12-23 08:21
I just read that Phones and tablets either use a magnetometer compass that uses the earth's magnetic field, or an electronic compass that uses GPS and accelerators, or a combination.

I would imagine that an electronic compass would suffer little to no affect from the test that I did. Still intriguing though.

it's always advisable to perform compass calibration. I suggest to calibrate it when inserted into the RC clamps, so as to compensate magnetic / paramagnetic compnents into the RC

Thank you for for sharing this informative video and thank you for your valued support.

emaneg Posted at 12-23 09:32
it's always advisable to perform compass calibration. I suggest to calibrate it when inserted into the RC clamps, so as to compensate magnetic / paramagnetic compnents into the RC

I did that and it made no difference in my case.  That somewhat surprised me.

with my galaxy note 9 the radar works fine

Ok I just tried the same experiment with my iPhone XR, Samsung galaxy s9 and iPad Air 2. None of the three compass readings on either device was affected to the degree by the RC that was shown in the video. In fact, none of the devices displayed any deviances even to one degree. Only thing I can think of is the shielding involved with the brand of phone, but without other devices to test with, still just conjecture.

JodyB Posted at 12-23 17:55
Ok I just tried the same experiment with my iPhone XR, Samsung galaxy s9 and iPad Air 2. None of the three compass readings on either device was affected to the degree by the RC that was shown in the video. In fact, none of the devices displayed any deviances even to one degree. Only thing I can think of is the shielding involved with the brand of phone, but without other devices to test with, still just conjecture.

JodyB, if you shield your mobile phone from external perturbating magnetic fields, you shield also as regards the magnetic field of earth, hence your compass can't give any indication at all!

There is another explication we are looking for...

emaneg Posted at 12-24 02:07
JodyB, if you shield your mobile phone from external perturbating magnetic fields, you shield also as regards the magnetic field of earth, hence your compass can't give any indication at all!

There is another explication we are looking for...

After thinking about it, I get that for those devices that work non-electronic compass. Which is what I’m thinking are the devices that are being affected. But in this case where they are being affected y the rc, some shielding between the rc and phone might do the trick, if that is what’s causing the issue with those certain devices. Again, my testing is nonconclusive since I don’t have access to other devices besides the three that I have.

What if you just rotated the phone 180 degrees?

From the symptoms that I've read, I would draw that it would be out 90 degrees the opposite direction. I saw a video where a guy rotated his phone from landscape mode to portrait mode and it corrected it. 90 degrees in other words. It would make more sense of the photo's that I've seen of the ones that are displaying this issue to be rotated 180 degrees. It's challenging for me because I don't have any affected devices to test with.....

I did a quick test:
- insert the phone between the RC clamps
- calibrate the compass
- it works more or less!!

I'll do more tourough tests (no metallic bodies around, reference compass available, cross-checking rotating the RC+phone body,...) to be definitely sure about.

Anyway, when you split RC and phone, you have to recalibrate the phone, obviously.

I took a whack at this and here's my results:



Seems like Metal interfernce is the key here, so looking at the exploded view/xray of a Galaxy S9 (Phone in video) you can see the antenna wires run along the top left side of the phone.


Looking at the Mavic Mini's controller (Curtosy of Dronedj) you can see the likely cause of our compass interferance.



My S9's orientation is off but most of the time it's correct, I feel like for those who have issues should try flippin their phones around or using a 3rd party tablet mount and mount the phone away from the radio but both of these requiire a longer cable per your device.

Can't edit the above post, but looking at the photo my antenna's are clearly at the bottom, but the motherboard/chipset is in that region otherwise and interferes with the device.