How many times do you have to calibrate the compass?

[Slowcaptain]

I've flown over 130 miles and the only time I calibrated was when I first got the Mavic last May.

Hmm. Could be a MA specific issue.

 

[BudWalker]

I gotta ask. Are you guys talking about this? (Courtesy of @msinger)
I

If so, then that's just telling you how to calibrate if you want to.

 

[Slowcaptain]

I gotta ask. Are you guys talking about this? (Courtesy of @msinger)
View attachment 34977I

If so, then that's just telling you how to calibrate if you want to.

Oh no, I get a specific warning - calibrate your compass. Then in 2nd screen capture where it says "normal" against compass - you see "calibration needed".

 

[BudWalker]

Oh no, I get a specific warning - calibrate your compass. Then in 2nd screen capture where it says "normal" against compass - you see "calibration needed".

Yikes, I just realized you have a Mavic Air. I'll bet your problem has the same root cause as these two incidents.

Mavic Air Fly-away
Another Flyaway

I, along with @sar104, thought those were due to powering on in a geomagnetically distorted location and then moving to a better spot before launch. But, I'm suspicious because this type of incident doesn't happen very often. I can only think of three in the two years or so that I've been looking at incidents. And now we have two in less than a week and it wasn't really clear what the cause was.

I don't have much in the way of a fix other than to send it to DJI for repair. But, if you have time could you do 2 tests.
1) The next time this happens let the MA just sit there for 5 minutes and see if calibration request goes away.
2) Perform an extended compass dance like this
Hold the AC in front of you with the X axis pointing away from you. Now, turn slowly in a circle while at the same time rotating the AC end over end in front of you. After turning 360 degrees stop and turn the AC so that it has the X axis pointing to your right. Repeat the slow turning while rotating the AC end over end in front of you. Finally, orient the AC with the X axis pointing to the left and repeat the slow turning while rotating the AC end over end in front of you.

For both tests could you proved the tablet .DAT. Here are some instructions how to do that.
How to retrieve a V3.DAT from the tablet

@Helgegustav
@Oliver_I

 

[danthecpa]

I don't know if this might relate to some calibrate compass issues but I noticed that starting the air on a concrete table at the park always led to compass calibration. When I moved away from the concrete table it didn't request it. My thought was the rebar in the table was causing an electrical interference. Just my observations.

 

[BudWalker]

I don't know if this might relate to some calibrate compass issues but I noticed that starting the air on a concrete table at the park always led to compass calibration. When I moved away from the concrete table it didn't request it. My thought was the rebar in the table was causing an electrical interference. Just my observations.

Almost certainly.

 

[Dragonfly]

You should only have to calibrate the compass once when you get your Mavic. If it keeps asking for calibration, something is seriously wrong with your craft and I would be very worried about flying it. (you are risking a fly away due to compass failure or incorrect direction for RTH). Send it back to DJI for repair or replacement. ASAP.

 

[Slowcaptain]

Yikes, I just realized you have a Mavic Air. I'll bet your problem has the same root cause as these two incidents.

Mavic Air Fly-away
Another Flyaway

I, along with @sar104, thought those were due to powering on in a geomagnetically distorted location and then moving to a better spot before launch. But, I'm suspicious because this type of incident doesn't happen very often. I can only think of three in the two years or so that I've been looking at incidents. And now we have two in less than a week and it wasn't really clear what the cause was.

I don't have much in the way of a fix other than to send it to DJI for repair. But, if you have time could you do 2 tests.
1) The next time this happens let the MA just sit there for 5 minutes and see if calibration request goes away.
2) Perform an extended compass dance like this
Hold the AC in front of you with the X axis pointing away from you. Now, turn slowly in a circle while at the same time rotating the AC end over end in front of you. After turning 360 degrees stop and turn the AC so that it has the X axis pointing to your right. Repeat the slow turning while rotating the AC end over end in front of you. Finally, orient the AC with the X axis pointing to the left and repeat the slow turning while rotating the AC end over end in front of you.

For both tests could you proved the tablet .DAT. Here are some instructions how to do that.
How to retrieve a V3.DAT from the tablet

@Helgegustav
@Oliver_I

Thank you for taking the time out and replying. I will retrieve the .dat file. Have raised a ticket with DJI already..
P. S. There is no flightrecord folder under my dji go 4. All I have is cache and files. Will it be created when I perform above steps?

 

[Slowcaptain]

You should only have to calibrate the compass once when you get your Mavic. If it keeps asking for calibration, something is seriously wrong with your craft and I would be very worried about flying it. (you are risking a fly away due to compass failure or incorrect direction for RTH). Send it back to DJI for repair or replacement. ASAP.

All this time I was thinking this is normal until my buddy came with his Spark and said he has not calibrated it in recent times whereas I kept calibrating it.
I'm out of 15 day period (17th day today after delivery) so it is pretty much repair only

 

[BIGLUG24]

I do a calibration every time i move to a new spot weather it's said to or not it can't hurt to do it and you may save your self a fly away

 

[Slowcaptain]

I do a calibration every time i move to a new spot weather it's said to or not it can't hurt to do it and you may save your self a fly away

The problem from other replies seems that since the aircraft is asking for calibration so many times, that could happen mid air too and cause a flyaway - whether you did a forceful or not compass calibration on the ground before flying.

 

[kon_jelly]

Mine asks me to calibrate almost every time I power on, mostly in the same location. Not only that, it can take 15-20 times trying to calibrate it before it finally accepts. I spent 20 minutes the other day just trying to get up in the air.

 

[turbodronepilot]

Mine asks me to calibrate almost every time I power on, mostly in the same location. Not only that, it can take 15-20 times trying to calibrate it before it finally accepts. I spent 20 minutes the other day just trying to get up in the air.

Call dji ,don't make a ticket online ,you'll get better service.
Dji support is hauling the mail these days..
Just tell them about needing to calibrate the compass frequently and they will ask if you want to send it in ..Say yes and in less than 10 business days you'll be back in the air.
My turn around time was less than a week and I got a new a.c. and r.c.
It doesn't get much better ..

 

[Unum]

Mine asks me to calibrate almost every time I power on, mostly in the same location. Not only that, it can take 15-20 times trying to calibrate it before it finally accepts. I spent 20 minutes the other day just trying to get up in the air.

Same here. Almost every time I go to fly mine it asks me to calibrate it. One time it refused to calibrate, too. I must have tried a dozen times in a row and the calibration kept failing.

 

[Lake_Flyer]

Mine asks me to calibrate almost every time I power on, mostly in the same location. Not only that, it can take 15-20 times trying to calibrate it before it finally accepts. I spent 20 minutes the other day just trying to get up in the air.

There must be something wrong with your bird. Or the location? If one of those locations is bad for calibration you stay in a vicious (bad)calibration circle. Try to find out a location where you're absolutely sure there couldn't be any magnetic interference or iron in the ground or whatever you can think of. Than do your calibration, test fly it, and if your satisfied, leave it for as long as you can. Don't calibrate every time the app tells you to. First try a location 30 feet away, or even further.

 

[Kilrah]

Had to do it nearly every time with the Air as well, but the last update fixed it.

 

[BudWalker]

Thank you for taking the time out and replying. I will retrieve the .dat file. Have raised a ticket with DJI already..
P. S. There is no flightrecord folder under my dji go 4. All I have is cache and files. Will it be created when I perform above steps?

The .tablet .DAT files are in the FlightRecords/MCDatFlightRecords folder. A .DAT is created whenever the Mavic Air is powered up and it is connected to the Go App. So you should be seeing several .DATs in the FlightRecords/MCDatFlightRecords folder from the previous flights.

I'm speculating that the compass is fine and doesn't need to be calibrated. The problem is that the Yaw isn't initialized correctly. This would have caused the incidents I referred to previously. In your case the FC sees the difference and issues a calibration request. By allowing the AC to sit undisturbed the FC should correct the Yaw value using the magYaw (compass heading value). This process will be slow since the FC uses mostly IMU values to update Yaw while the compass value is used at a much lower gain. The first test I described should show if this is in fact the case. The second test should show if the compass needs calibrating.

Had to do it nearly every time with the Air as well, but the last update fixed it.

It's hard to imagine a HW problem that would cause Yaw to be initialized incorrectly that doesn't also affect subsequent flight. It would almost certainly be a SW problem.

 

[kon_jelly]

There must be something wrong with your bird. Or the location? If one of those locations is bad for calibration you stay in a vicious (bad)calibration circle. Try to find out a location where you're absolutely sure there couldn't be any magnetic interference or iron in the ground or whatever you can think of. Than do your calibration, test fly it, and if your satisfied, leave it for as long as you can. Don't calibrate every time the app tells you to. First try a location 30 feet away, or even further.

I doubt it's the location as where I usually fly is pretty remote and there shouldn't be much of anything to interfere. It's also not limited to a single location - the exception for me is to power up and not need to calibrate. My Spark never needs recalibration and I fly it in all the same areas.

I'm also on my second Mavic Air that has experienced the issue. I've seen enough reports of the exact same behavior on the official forums that I'm thinking it's a larger issue that DJI needs to address. I'm going to hold off on sending it in for now, but if it keeps up for another week or two I'm sure I'll be frustrated enough to send it back.

 

[Kevjones777]

Lol
I guess so too.
I am told if you fly it at different locations, bird will ask to calibrate. In my case it keeps asking regardless I travel or not. As soon as I switch batteries, it needs calibration - 90% of the times.

I read on the DJI site that when it asks you to calibrate, you should calibrate it then switch it off and on again. ?? Wonder why this is required.

 

[Mr G]

Look around for any metal objects that might affect your drone. Objects like: a metal part bench, too close to your vehicle, fence, etc. And don't forget that most commercial cement has metal supports in it!