Raw Compass Numbers Out of Range?

[DroneTone]

I'm concerned that my raw Compass Calibration numbers may be out of whack.
Specifically the X and Z numbers, the Y and Mod values seem within range.
I'm assuming normal number ranges for X, Y and Z are: + or - 300
Compass Mod range: 1400-1800
I know that Mod = square root of (X*X+Y*Y+Z*Z).

First a bit of preface: Phantom 3 Professional, Firmware v1.6.0040, using an Pad Air DJI GO app v2.4.3.
I have successfully done several cold IMU re-calibrations and gimbal re-calibrations on level surfaces, indoors.
I have successfully done numerous compass calibrations outdoors in grassy open fields or baseball diamonds in different locations on different days.
During compass calibrations I do stay away from concrete rebar, buildings, any other metal and take all metal objects off my person such as keys, cellphone and spare change.

I do not get any messages from the Phantom saying anything is wrong with the compass or any other problem.
I usually fly in P-GPS mode with no issues, it holds a selected altitude well with only small wind corrections.
My longest distance has been about 3/4 mile away and 390 ft. altitude.
I can easily get the phantom into a stable hover slightly above me for hand-catching or hover into a soft landing.
The Phantom does not exhibit any "TBE" or toilet bowl effect or wavering during a hover.

X Y Z Mod
Initial Compass -516.00 275.00 1401.00 1518.12
Calibration #1 -516.00 272.00 1387.00 1504.66
Calibration #2 -512.00 313.00 1367.00 1492.92
Calibration #3 -518.00 316.00 1363.00 1491.96
Calibration #4 -526.00 322.00 1359.00 1492.39
Calibration #5 -523.00 250.00 1375.00 1492.20
Calibration #6 -534.00 154.00 1383.00 1490.49

So basically the P3P seems to fly okay, but I'm concerned these compass numbers could be the sign of
a more serious compass error and the potential for a fly-away in the future.

Doing numerous compass calibrations does not seem to be able to bring these numbers back into range.
The only reason I can think of that would cause the abnormal readings is that during several initial flights I did use my Apple case for the iPad as a launch pad for protection from some tall or wet grass.
I had forgotten the Apple case has two segments on the top cover which are magnetic.
I am wondering if the case cover lying underneath the Phantom could have magnetized the compass in the legs.

How can these raw compass numbers be brought back into range?
Continue to repeatedly do compass calibrations?
Is a degaussing needed? Should a Phantom 3 be degaussed?
If so, is the procedure the same as the one in the YouTube video for degaussing the Phantom 2?

In addition, it may be related or not, in the GO app, lower left screen Flight Telemetry, the red arrow pointer does not exactly agree with where the Phantom is pointed. Sometimes the red arrow points about 20-30° to the left of where the Phantom is pointed (on the ground and in the air). Calibrations have seemed to gotten it more accurate, the red arrow now points about 5° too far to the left, which is acceptable for the moment.

Any help is appreciated-
Thanks

 

[BudWalker]

These numbers are fine. In fact they look great. There is no constraint about X, Y, and Z being [-300, 300]

 

[DroneTone]

Thanks BudWalker- Nice to know.
Any thoughts on keeping the GO app telemetry red arrow in agreement with how the Phantom is actually pointed?

 

[BudWalker]

Thanks BudWalker- Nice to know.
Any thoughts on keeping the GO app telemetry red arrow in agreement with how the Phantom is actually pointed?

I think I've seen @msinger answer this one. Maybe he has a ready answer.

 

[Meta4]

In addition, it may be related or not, in the GO app, lower left screen Flight Telemetry, the red arrow pointer does not exactly agree with where the Phantom is pointed. Sometimes the red arrow points about 20-30° to the left of where the Phantom is pointed (on the ground and in the air). Calibrations have seemed to gotten it more accurate, the red arrow now points about 5° too far to the left, which is acceptable for the moment.

Two compasses are involved ... One shows which way your Phantom is pointing and another tells your tablet which way it is pointing.
Have you ever calibrated your tablet's compass?
Google will show you how to.

 

[msinger]

Any thoughts on keeping the GO app telemetry red arrow in agreement with how the Phantom is actually pointed?

This usually means the compass needs to be calibrated on your mobile device. Try this:

 

[Liamus27]

Bumping on old (ish) thread but want to understand more about these raw compass values - what they mean and how I can use them. Please can someone help or point me in the right direction?

 

[Badboar60]

I am having an issue with one of my P3P's. The aircraft heading and compass on my iPhone do not line up properly as being discussed. If I set up my 2nd P3P the compass points correctly when connected. Same iPhone used. I preform calibration of the compass regularly. Firmware and RC software are the latest for both.

Any ideas would be appreciated!

Thanks Badboar

 

[DroneTone]

Assuming your P3P compass is calibrated within tolerance, I would check the remote controller being used.
Calibrate the joysticks on that controller using the DJI Go app.
Note that to do this the controller and iPhone or device must be powered on and connected with the DJI GO app running;
but the P3P must be left turned off.

Beyond that, calibrate the IMU of that P3P, but you've probably already tried that.

 

[Badboar60]

Great, I am going to give that a try. Just so I understand, do the joy sticks interface with other operations in addition to just "joy sticks"? Last, this is an assumption on my part, if the aircraft is operational during the cal, can the compass in the aircraft be dominating the compass in the iPhone, inhibiting it's ability to freshen up so to speak? I am a newbie so please forgive me for asking too many question. I will generally never waste your time until my search comes to that "Dead End" road.

For whats it's worth, I had been spending the last 3 days with a competitor forum and still had not been able to asked any questions. Only took 15 mins with you guys. You are number ONE!



Thanks for all your help!

Badboar

 

[DroneTone]

Just to be clear, the aircraft should not be powered on when calibrating the RC joy sticks.
The aircraft compass is independent of the compass on the iPhone or other device.

When the joysticks are miscalibrated, moving the stick in one direction tells the aircraft to move in a slightly different direction than intended.
This sometimes appears to some users as being a compass error, when it is not.
You will only see this issue while moving the aircraft in a desired direction.

Joystick calibration won't correct a discrepancy noticed only while the aircraft is standing still.
This discrepancy appears as a difference between the red arrow on the little radar screen in the DJI GO app
and looking at the actual direction the aircraft nose is pointed.
This is either an IMU or compass calibration issue that needs attention.
It also could be simple magnetic interference found at that particular location.

Also, there have been users whose aircraft compass became magnetized unintentionally by having the P3P near some strong magnetic field,
such as a large speaker cabinet or something containing a large magnet.

A possible (but risky) solution is to use a demagnetizer or degausser on the P3P to try to remove the magnetic field that was induced.
I'd only use this as a last resort though and if it was confirmed that the P3P had somehow become magnetized.
It is possible to actually make the magnetic field stronger instead of removing it if you are not careful.
This would make the compass error worse and even harder to correct.

I would also do a search on this forum for "Compass Errors", I know there are other users who have complained of your issue.