MA2 remote interferes with cellphone's compass.

Vaideeshwar · May 13, 2020

MavicMike55 said:
Just curious.... Is there a case on your phone? If not, maybe using one might give you the shielding you need. If using one already, perhaps placing a thin sheet of plastic or something else inside the back of the case. Just something to think about. Am curious, since I too will be using a note 10+ when I get my bird in a few days.

I tried with and without a case, no difference whatsoever.

Thank you for your suggestion though!

Vaideeshwar · May 13, 2020

MavicMike55 said:
,
Well, why then, when I use the magnetic phone mounts, do they NOT work as well when you put the metal plate on the inside of the case? That certainly seems to have an effect. Mr. SMARTEE PANTS?? hmmmm. ??

So I think when you use a magnetic phone case, the magnetic region is only along one boundary (edge) of the phone. With this antenna though, the metal sliding railing sits right behind the phone at the dead center. I think that this railing is much closer to the phone's compass when compared to something at the sides of the phone.

Vaideeshwar · May 13, 2020

sar104 said:
I think that's very unlikely. The current flowing in the antenna cable is small and UHF - it's not going to magnetize anything. If there is a ferromagnetic component (what is the slider made of?) then it could become magnetized, but it would not be from the antenna system. Have you checked the RC with a compass or magnetometer to see if you can isolate the source of the magnetic field?

I believe this slider is a thin steel tubing. Yes, the effect isn't a lot though. Just about 15 degrees in both yaw direction and orientation. The proximity of this EM wave to the phone compass might just be causing this.

I am only saying this because I have tried two other different Mavic remotes (MM and MA1). They were spot on, despite the phone being almost the same distance away from the controller sticks as in the MA2.

itsneedtokno · May 13, 2020

Look at the way he puts his phone at 4:47

Maybe you can try this?

I know it's not ideal, and throws off the balance, but for a temporary quick fix, could be worth it.

Vaideeshwar · May 13, 2020

itsneedtokno said:
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Look at the way he puts his phone at 4:47

Maybe you can try this?

I know it's not ideal, and throws off the balance, but for a temporary quick fix, could be worth it.

Thank you for your suggestion. That would definitely help if it is indeed the metal railing and the electrical wiring inside it causing the issue. I will definitely try that out to see how it does.

Honestly, I am still getting used to the new center of gravity of the system because no part of the hand supports the weight of the phone (as in the previous design, the palm completely supported the phone).

I think getting a mount would do two things:
1. elevate the phone and bring it physically towards you (the C.G. is no longer that far away from the palm)
2. distance the phone from any source of EM waves.

But for now, I will definitely try out what you said and respond back!

Thanks, mate!

sar104 · May 13, 2020

Vaideeshwar said:
That is 100% correct, in fact, there is something called a Mu Metal that is supposed to be a magnetic shield, but it is a metal itself.

Mu metal acts as a shield, but not because it is impermeable to magnetic fields but rather completely the opposite - it has unusually high magnetic permeability. As a result the magnetic flux lines preferentially run inside the mu metal and can be routed around other materials.

Vaideeshwar · May 13, 2020

sar104 said:
Mu metal acts as a shield, but not because it is impermeable to magnetic fields but rather completely the opposite - it has unusually high magnetic permeability. As a result the magnetic flux lines preferentially run inside the mu metal and can be routed around other materials.

Ah, true! That is what I remember reading a few years ago when there was a need for magnetic shielding for some project.

Thank you for all the info you provided so far. I think it is a case by case type of deal. I guess my phone has the compass in a position that allows it to be influenced by the EM fields creates by different matter.

sar104 · May 13, 2020

Vaideeshwar said:
Ah, true! That is what I remember reading a few years ago when there was a need for magnetic shielding for some project.

Thank you for all the info you provided so far. I think it is a case by case type of deal. I guess my phone has the compass in a position that allows it to be influenced by the EM fields creates by different matter.

But compasses are not affected by RF EM fields.

Vaideeshwar · May 15, 2020

UPDATE:
So I tried a different orientation- I flipped the phone by 180 degrees (the USB C port of the Note 10+ is now on the left) and moved the phone physically to the left, offsetting the center of the phone (where I suspect the compass to be) from the antenna slider and the orientation issues seem to be almost completely resolved. There still is a small bit of aircraft yaw direction error and a small angular offset of the aircraft relative to the pilot, but is very minimal (both about 5 degrees both), which I can live with.

Thank you all for your suggestions!