I sent my first Mavic Mini back within a week because of a compass orientation problem with the app display. This was early December 2019.

The drone stopped connecting to the app display. Once the drone was in excess of 50 meters away, I struggled to tell which way it was pointing or if it was flying away or towards me, so it went back to Amazon.

I recieved a replacement Mavic Mini this week. This time the app dispaly shows that the drone is 180 degrees behind me. No matter which way I orentate the transmitter/phone, the app display of the drone keeps rotating irratically.

I have to say that the RTH feature works fine, and watching my drone on the full-size map plots accurately. I just can't trust the orentation of the drone from looking at the app dispaly.

Yesterday I discovered that some phones cause compass problems with the transmitter and it would seem that my Pixel 3a is one of those phones.

I did a simple test of installing a compass app on my phone. I then moved the phone towards and away from the transmitter and noticed that this affected the compass needle displayed on the phone. However if I span the phone 180 degrees so that the USB C port was on the right side of the phone, then the compass needle would not be affected by moving close to the transmitter.

Would it be best to get a longer cable so that I can rotate my phone 180 degrees while connecting it to the transmitter?
Or should I get a cheap compatible phone that does not interfere with the compass?

Hi. Thank you for reaching out to DJI Forum. I hope that our valued DJI co pilots can provide you the best information for this inquiry. In addition, I would recommend to please try a different recommended mobile device to isolate the issue  Please keep us posted for further assistance. Thank you.

There’s a small map in lower left corner this will show which direction your craft is flying and it’s always correct, it also uses a trace so it’s simple to get drone on track .

Another option is to elevate your phone in a bracket.

DJI Paladin Posted at 1-20 11:47
Hi. Thank you for reaching out to DJI Forum. I hope that our valued DJI co pilots can provide you the best information for this inquiry. In addition, I would recommend to please try a different recommended mobile device to isolate the issue  Please keep us posted for further assistance. Thank you.

I feel like DJI is treating me as a BETA Tester and I have the privilege of paying Full Price for the honour.

My phone, a Pixel 3a, hasn't been out for a year yet. It has the latest operating system, Android 10, and a Security Patch dated 1 January 2020.

Its not as if I am trying to use an old obsolete phone, or one which did not sell well. Yet my Pixel 3a is not compatible with DJI's Mavic Mini Remote Controller.

I have done a simple test, by downloading a compass app, and observed that the Remote Controller does DEFLECT the compass on the phone. This in turn affects the navigation features of the Remote Controller which I have observed in the simple fact that the Remote Controller and the DJI Fly app can not accurately show the orientation of my drone while in flight.

This could have expensive navigation consequences.

However I have tested my Mavic Mini with a mate's ageing iphone 5 and the flight and experience was flawless. Not a single problem or hitch.
I was so pleased with the result that I bought a second-hand iphone SE to work with the Remote Controller.

I can confirm that the second-hand iphone SE, which is almost 4 years old, with operating system iOS 13.3, works perfectly with the Mavic Mini.

I am hoping that the iphone will only be a temporary measure, however I am liking the fact that it does lot leach battery power from the Remote Controller or my DJI Osmo Pocket, like my Android phone does without me being able to stop this vampire trait.

I am still holding out for my Pixel 3a. I a couple of days I should receive a Micro USB to USB C cable which will allow me to position my phone further away from the Remote Controller to try and reduce the compass being deflected and affecting the safe flight of my drone.

I should not have to do this though!

the lemming Posted at 1-21 06:36
I feel like DJI is treating me as a BETA Tester and I have the privilege of paying Full Price for the honour.

My phone, a Pixel 3a, hasn't been out for a year yet. It has the latest operating system, Android 10, and a Security Patch dated 1 January 2020.

This is a problem already discussed in many threads and affect many cell phones, because magnetic interferences between metallic/magnetic stuff inside the RC and the phone magnetometer.

One solution consists in placing your phone in the RC clamps and then make a phone compass calibration.

Usually it works

emaneg Posted at 1-21 07:28
This is a problem already discussed in many threads and affect many cell phones, because magnetic interferences between metallic/magnetic stuff inside the RC and the phone magnetometer.

One solution consists in placing your phone in the RC clamps and then make a phone compass calibration.

A problem discussed in many forums?

Well why isn't DJI informing people in its advertising?

The Mavic Mini got a lot of good publicity. That can all fade quickly.

the lemming Posted at 1-21 08:01
A problem discussed in many forums?

Well why isn't DJI informing people in its advertising?

DJI is not goimg to advertise the malfuncions of their products, of course! They may add few lines on the user manual to explain how to match phone+RC without inconveniences.

I experienced the same compass problem with my HUAWEI P10.
Everytime  I connect thephone to the controller, a compass calibration is needed.
I did as the same test as Lemming did and actually the controller interfere with the phone compass and viceversa.
The orientation of the drone is not displayed correctly on the app.
RTH works well, never had a problem.

Anyway it is annoying. I hope it will be solved by DJI.

They cannot correct the problems since it's battery and mobile phone related, depending on the exact placement of the magnetometer withing the mobile phone itself relative to the position of the battery inside the remote and some other components.

The best one can do a is compass calibration one the mobile device WHILE attached to the RC. Wave the assembly in a figure of 8 motion, do 360° turnaround. I also use GMaps to verify and calibrate compass. Once calibrated the half circular bottom heading indicator works fine, even with my S9+.

I have an update about an extended USB C cable.

the lemming Posted at 1-23 12:32
I have an update about an extended USB C cable.

Aggg.
Quick reply was a fail.

I bought a Micro USB to USB C cable from an ebay Vendor for £2 and I am sorry to say that I could not get the Remote/phone to connect to the drone.

However this was a sample of one cable. I am not going to buy any more cables as this could prove a costly experiment.

You should check and make sure that the cables are DATA cables, not charging cables.
There is a difference, being 2 missing signal wires for the data.
Try the cable that came with your "suspect" phone, that is a data cable,

and I bet it will fix your issues with connectivity and the compass....

Flycaster Posted at 1-23 13:19
You should check and make sure that the cables are DATA cables, not charging cables.
There is a difference, being 2 missing signal wires for the data.
Try the cable that came with your "suspect" phone, that is a data cable,

Try the cable that came with your "suspect" phone, that is a data cable,

May I ask what cable you are trying to describe?

The cable that connects to the bottom port of your controller to your tablet/phone.

Flycaster Posted at 1-24 07:45
The cable that connects to the bottom port of your controller to your tablet/phone.

Have you actually handled a Mavic Mini Remote Controller?
Or are you just assuming that all Remote Controls have the same configuration of ports?

You are correct and my mistake.
I was in the Mavic Pro mindset...
Nevermind...