Mavic Air + Apple Watch! Compass calibration

#1

I have never had problems with M2 Pro, Anafi and a Visuo xs812 with regard to compass calibration. Tend not to do it with the first 2 unless asked which I haven’t recently.

The Air has been a different matter. On one occasion I put it down to a large metal ships container some 100m away so I moved 200m away and after several tries managed calibration. Had this experience a few times with no obvious magnetic interference objects near. Experienced this again the other day and moved all over the place to try to calibrate with magnetic interference warning appearing wherever I tried. Trying in the middle of an empty car park with no cars and failing gave up and flew the M2 Pro and Anafi without issue.

On arriving home remembered someone on the Mavic Pilots forum mentioning that wearing a watch can be an issue. Unlikely I thought! Took my Apple watch off which indeed does have a magnetic charging system and ventured into my garden. No magnetic interference warning and calibration took a couple of twirls of the drone - job done.

Went back to the same site I couldn’t take off from previous day in same spot minus watch. No problem and not asked to calibrate despite significant change of location. Flew flawlessly.

Don’t think I have “proved” anything yet but it does seem in my case that wearing a magnet may well be the cause. Will need to try a few more times to see if leaving the watch in the car means less calibration requests and compass errors. Possibly get companion flyer to do the twirling at some distance away from me with my watch on and see how that goes,

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#2

Yes, I have also had the exact same experience wearing an apple watch and the magnetic interference it can cause

#3

Nothing for me in 2 years of Apple Watch wearing, in fact I cannot remember the last time I did a compass calibration, and it’s been abroad half a dozen times while I’ve had my watch

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#4

But you are using a Mavic Pro - yes?

The phenomena is specific to the Mavic Air apparently. I also have no issues as said with 3 other drones just the Air.

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#5

Yeah MP, and flown a MP2, and Phantom 3 and 4 with no issues.

Very strange

#6

You should really do a compass calibration every time you take off in a new place, or country especially after going on a plane. According to my NQE

#7

I was out with my MA this afternoon. The Air has asked for calibration before when I was 130 miles from home but normally it is fine for several miles around home.

I was at a take off site 5 miles north of bricks and mortar home and compass calibration was required. Appparently if it hasn’t been flown in the previous 31 days it will ask for re-calibration. I calibrated it, made a Litchi controlled flight and it came home without fuss and landed back on the “H” pad automatically.

I changed batteries and it asked for compass calibration again. The second time it also calibrated and flew without fuss.

The one difference to normal? I’m wearing a watch/blood pressure monitor/pedometer thingy I got cheap off Banggood. Seems like the watch theory could be correct!

#8

Yet DJI state only to do one when prompted

#9

I’ve always removed all metal from me when calibrating compass, keys, coins, watch, glasses, belt buckle, phone etc.
Never had a problem,
Cheers
Steve :slightly_smiling_face:

#10

Compass calibration usualy fails if I’m wearing my watch (non smart).

On the first part of calibration the watch is affecting the magnetometer but let’s you go to second step as it’s taken it into account.

On second step your are holding the drone differently and it affects the magnetometer on a different axis.

Luckily the drone is smart enough to know this is outside interference and the calibration fails.

#11

Really where did you see that?

#12

Page 50 of this manual says:

Only calibrate the compass when the DJI GO 4 app or the status indicator prompt you to do so

Other drones / models may differ.

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#13

What about a P4?

#14

Goodness! I don’t fancy taking off with trousers round my ankles. Not in this cold weather for sure. Shrinkage and all that …

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Interference from Nearby Objects
#15

I’ve no idea, you’ll have to read the manual.

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#16

This very lengthy thread on Mavic Pilots is I think where I first came across the watch/other devices suggestion for why there may be calibration failures and repeated requests to calibrate. The theories in that thread are legion but for now I’m going with the watch theory. Hopefully further test it again soon.

There is clearly something special/different about the Air compass since there are so many reports of issues. I’m sure I read somewhere it had 2 compasses? Although I might have dreamt that.

#17

Agreed, just going by the number of times it asks to be calibrated :scream:

Does it only have one compass? :thinking:

#18

V2.0 Mavic Pro manual is a little different.

Calibrating the Compass
It is recommended to calibrate the compass in any of the following situations when flying outdoors:

  1. Flying at a location farther than 10 km away from the last flight location.
  2. The aircraft hasn’t been flown for more than one month.
  3. A compass interference warning appears in the DJI GO 4 app, and the warning persists after chang-
    ing location.
    Restart the aircraft when calibration is complete.

This is also the procedure for the single compass Mavic 2.

Not sure why they added it to the Mavic 1 manual as well as it was never an issue :man_shrugging:

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#19

Q.E.D. !
Managed to get the Air out for a quick fly today. Left watch in car but retained belt buckle. Not a sniff of a request for calibration or hint of magnetic interference. All ready to fly within seconds of switching on.

Calibrated the compass anyway - two apparently. Two twirls and in the air.

Used my new iPad 5 for first time with latest Go 4 4.0.29. No issues and rock steady in a moderate breeze. Unlikely to be in the air tomorrow with weather that’s promised.

Pleased to have identified the compass issue.

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#21

I hadn’t noticed he was using similar but different gloves. The PGYTECH gloves don’t have magnetic closings so that’s why I didn’t have any issues.