P4p compass error “Strong Magnetic Interference” issue

[jephoto]

Finally. Someone is seeing why this is baffling to me.
I know this. There have been times when I first got a compass error and merely by holding the drone in my hand 4 feet off the ground I was able to get a compass lock.

The message I got was similar to the photo above “compass error. Move to new location or recalibrate”

I’m this case I started in a parking lot. Error. Thought maybe rebar under the asphalt was an issue.
Moved to grass strip between Street and sidewalk. Error.
Moved to empty lot across he street, covered in grass. Error.
Walked a block away. On someone’s lawn Error.
Drove 2-1/2 blocks away, went into an actual park. Error.

After trying to recalibrate and Failing, message changed to “Strong Magnetic Interference.”

Then I pulled out the P3. No error. Immediate GPS lock.
Went back to original location and flew the job with the P3.

Then later drove 90 miles back home. Put the P4p down in my cement tile covered backyard, and got a normal lock, and flew.

This is why I’m trying to sort this out. I should have been. Able to get it to go by moving to that park.
Or recalibrate.

I was wearing the same clothes, same phone, same every **** thing I always do when flying- and had 2 days before in a VERY industrial site with ComEd transformers and power plants all around me.
There was no mystery metal on me or near the drone.

Do you now get it? This should not have been a problem. Yet it was.

 

[Meta4]

This is why I’m trying to sort this out. I should have been. Able to get it to go by moving to that park.
Or recalibrate.

If the issue is magnetic interference, recalibrating the compass is never the solution.

Do you now get it? This should not have been a problem. Yet it was.

I get that it's a mystery.
I had to go through a few possibilities to eliminate things.
I can't guess what the issue is.
If there was some mystery magnetic field at your launch point, it wouldn't also be felt blocks away.
If there was a problem with the drone, it wouldn't work at home.
As they say in the classics ... Scientists are baffled.

 

[jephoto]

Further update. Took the P4P 1/2 mile from my house to shoot the nearly finished construction of a new neighborhood library.
No errors. GPS locked in under 30 sec. flew just fine.

Although I did have one weird thing happen in first minute.
I took it to maybe 80’- above tree height near me, shot a still, flipped camera down 90& shot another as a divider between a pano sequence, and the camera seemed stuck writing to the card. Wouldn’t let me rotate the camera back, or do any other camera functions. The spinning icon that lets you know it’s wrting to the card just kept spinning and spinning.
So I brought it immediately down and turned the battery off & on.
Still spinning. Turned off again and took off my gloves.
I was wearing some photo gloves that have the index finger and thumb with the tips that fold back and have small magnets in the tips to hold the folded part back out of the way.

Turned on the drone and flew normally next 1/2 Hour.
I’ve no idea if the gloves affected the drone or camera. Not sure really how it could - but that’s the sequence.
Now I need to repeat the test and see if those gloves affected the drone operation in any way.

My head says the tiny magnets in the glove tips (just on the two fingers) shouldn’t affect the operation of the drone when 80’ away, but it’s possible that a small magnet near the controller could.

Although the main difference here to my problem in Milwaukee, is that I had no compass issues at all and was able to fly just fine.

Another mystery. But maybe related. I only bought these gloves a couple months ago and being winter hadn’t been flying out until 2 weeks ago. More testing needed...

 

[sar104]

If you want to find out exactly what is happening, as opposed to generating pages of guesses and speculation, then you are going to need to retrieve the DAT files from your mobile device and/or aircraft. Those contain the raw magnetometer data and event stream log.

 

[David_Cambridge]

The small magnets are certainly permanent magnets which are just the kind that will bother the drone if it is close - 10 feet or less. Should throw strong field message on tablet. Set drone down and walk away until warning clears. I don’t know how frequently the magnetic warning updates, so it make a couple of minutes.

NOTE if you calibrate the compas with those gloves on you hopefully get calibration failures. If you don’t, you will be flying with a potentially mis calibrated compas.

Permanent magnets are very capable of permanently magnitizing anything they come close to, a very dangerous thing to do to a drone. These are far more troublesome than high current power lines which have far higher magnetic fields, but reverse themselves 60 times a second, performing a demagnetization of any object drawn through the field.

 

[jephoto]

If you want to find out exactly what is happening, as opposed to generating pages of guesses and speculation, then you are going to need to retrieve the DAT files from your mobile device and/or aircraft. Those contain the raw magnetometer data and event stream log.

Thanks. Will do.

 

[jephoto]

The small magnets are certainly permanent magnets which are just the kind that will bother the drone if it is close - 10 feet or less. Should throw strong field message on tablet. Set drone down and walk away until warning clears. I don’t know how frequently the magnetic warning updates, so it make a couple of minutes.

NOTE if you calibrate the compas with those gloves on you hopefully get calibration failures. If you don’t, you will be flying with a potentially mis calibrated compas.

Permanent magnets are very capable of permanently magnitizing anything they come close to, a very dangerous thing to do to a drone. These are far more troublesome than high current power lines which have far higher magnetic fields, but reverse themselves 60 times a second, performing a demagnetization of any object drawn through the field.

And if I had worn them when calibrating my drone last - after an IMU - that might be it. But it's not.

Nor do I hold the drone in my hand when starting up- its on the ground 5-10' away. I turn on the battery & back off.
Believe me I tried every different thing I could think of when i had the compass problem.
-Restarting the drone.
-Restarting the Go4 software
-Rebooting the iPad
- attempting finally to recalibrate when in that park- but failing

But don't remember if I had those gloves on or not. Even if I did initially, they would have ben off by the time I got the that park blocks away from the job.

And yet when home - and now 1/2 mile away - flys perfect.
Which suggests it was the location.
Except for the P3P flying fine.

I'm only obsessing on this so I won't screw me up on jobs down the line. need to find out what the issue is - or was.

 

[GaryE2018]

I live out in middle national forest, very few power lines. No towers.
But back last year could take off from home point no issue, but about 2000 feet away around 150 to 200 ft AGL strong magnetic field land immediately.
Bought in checked all everything ok, this happened several times untill it just stopped. I've never had that issue in that area again. I know there are not anykind of steel metal or anything.
I've often wondered if could been some type of sun burst, or government test but just weard. Sorry I no this dosen't help any but drones do act funny sometimes just when you needthem.

 

[GWAYGWAY]

Is your tablet magnetic sitting on the controller whilst you play about????????????

 

[jephoto]

Yup. Thx .
Just got in from flying a few miles away. Again mo problems.
At least I'm confidant it's not the drone. Still didn't try it with those gloves again though. but I will in coming days.

Is your tablet magnetic sitting on the controller whilst you play about????????????

um... who are you asking and what exactly do you mean?

 

[Meta4]

I live out in middle national forest, very few power lines. No towers.
But back last year could take off from home point no issue, but about 2000 feet away around 150 to 200 ft AGL strong magnetic field land immediately.
Bought in checked all everything ok, this happened several times untill it just stopped. I've never had that issue in that area again. I know there are not anykind of steel metal or anything.
I've often wondered if could been some type of sun burst, or government test but just weard.

The sun and government tests aren't going to have any effect on your compass.
And if you are 150+ feet above the ground, nothing in the ground will either.
A more likely explanation is that you launched from somewhere close to a magnetic field and your drone brought up the error when you got away from the field and/or turned the Phantom.