Concrete magnetic compass error

[sparky1111]

This is a first for me.
I was sat on a concrete sea defence when I kept getting magnetic interference and to recalibrate compass.
I did this at least 4 times and eventually I restarted the craft and software and it disappeared. I took off and got a few feet away and had the same error. I basically lost control but due to the fact I was suspicious I only had an altitude of 6ft so I could grab it and switch it off.
I then downloaded a magnetic interference app and I was shocked by the readings sat on the pier and doing a baseline 50ft away.
An innocent wall lying in wait to kill my drone. Obviously the steels that reinforce the structure had an impact. Scary! Pictures and screenshots below showing the lowest reading on the wall and highest away.
Anyone else had this issue?

 

[stones]

I'd be interested in what the app is.
Thanks

 

[msinger]

Yes, this is a well known issue. Any magnetic metal object that is nearby can confuse the compass. I found all is well for me when my Phantom is 10+ feet away from all magnetic metal objects.

 

[Pharm]

Maybe if you apply a pipette of Advocate to the wall, the magnetic interference will disappear.

I haven't done any testing but after reading the 8 bazillion threads on here about metal in concrete interfering with the compass, I just don't take off anywhere near them.

Hope Alfie remains flea, tick, and heartworm free!

 

[sparky1111]

Ultimate EMF detector. Free.

 

[sparky1111]

Maybe if you apply a pipette of Advocate to the wall, the magnetic interference will disappear.

I haven't done any testing but after reading the 8 bazillion threads on here about metal in concrete interfering with the compass, I just don't take off anywhere near them.

Lol. Funny. You seen it then [emoji23] [emoji23] [emoji23]

 

[Pharm]

Lol. Funny. You seen it then [emoji23] [emoji23] [emoji23]

Yes, I saw it. I also saw an opportunity to tease you about it and I took it. Have fun!

 

[Richard R]

This is a first for me.
I was sat on a concrete sea defence when I kept getting magnetic interference and to recalibrate compass.
I did this at least 4 times and eventually I restarted the craft and software and it disappeared. I took off and got a few feet away and had the same error. I basically lost control but due to the fact I was suspicious I only had an altitude of 6ft so I could grab it and switch it off.
I then downloaded a magnetic interference app and I was shocked by the readings sat on the pier and doing a baseline 50ft away.
An innocent wall lying in wait to kill my drone. Obviously the steels that reinforce the structure had an impact. Scary! Pictures and screenshots below showing the lowest reading on the wall and highest away.
Anyone else had this issue?

Reinforced concrete is always going to mess with your compass. Just a recommendation, but I never automatically calibrate the compass when that message comes up. My first suspicion would be that there is something metal nearby that is confusing the compass. Move the bird first, if it clears up, you know that was the problem. Calibrating the compass to in an area where the fields are distorted will usually then give you problems after you take off just as you experienced.

 

[sparky1111]

Reinforced concrete is always going to mess with your compass. Just a recommendation, but I never automatically calibrate the compass when that message comes up. My first suspicion would be that there is something metal nearby that is confusing the compass. Move the bird first, if it clears up, you know that was the problem. Calibrating the compass to in an area where the fields are distorted will usually then give you problems after you take off just as you experienced.

Good advice! Thanks. [emoji106]

 

[Fester]

The App store for the iPhone/iPad, has several free apps including on called "Tesla Bot" that gives you geiger counter like clicks as feedback. Normal Earth magnetic field readings without "interference" will run around 50 microtesla, depending on your location.

 

[Joo]

Hey guys through a lot of research and reading I found a way to fix the common compass error problem if it gets magnetized that code will come up all the time go to Amazon by a simple plug in D magnetizer and hold it over the compass in the landing gear for a few seconds then take it out and re-calibrate you'll be amazed the problem will be fixed

 

[Tim Dawes]

Can you take off around magnetic interference and make a rapid climb out of it?

 

[Whitwellian]

Just over a month ago I wanted to try a flight at Hemsby, just N of Great Yarmouth in Norfolk (UK). I chose the seaward side of the sand dunes and prepared for flight with my Phantom 4. She gave a warning that the compass wasn't calibrated, which I tried to calibrate until I was dizzy, all to no avail.

Went back to the camp I was staying on, calibrated very well and had a couple of good flights.

The area of the sand dunes that I was setting up in had a couple of large concrete blocks just peeping out of the sand, but it surprised me the affect of the reinforcement bars. I'll have to be more observant next time. Fortunately, no harm was done.

I like the links to the magnetic field monitoring apps above. Must download one!

 

[harold guadalupe]

Does anyone know what the allowable readings are?

 

[sparky1111]

Do a Base reading first away from all structures. Perhaps take 3 readings away from structures add them together and divide by 3 to get your average readings. Dji don't give minimum readings so we're left to the on board compass to tell us when.
I'm my opinion only I'd say anything above 50 would prompt me to move to another location.
Whilst I was sat on the wall it went over 100mgausse but wasn't stable. However for sure the further away u walk feom the structure the weaker it gets.

 

[Meta4]

I chose the seaward side of the sand dunes and prepared for flight with my Phantom 4. She gave a warning that the compass wasn't calibrated, which I tried to calibrate until I was dizzy, all to no avail.

Your Phantom did not warn you that the compass was not calibrated. The compass does not lose calibration.
It was warning you that it detected a magnetic influence significantly different from the earth's normal magnetic field.
When you get this, recalibrating is the last thing you should consider doing.
The correct action is to simply move away from the magnetic distortion to a clean area.

There's no need to recalibrate a perfectly good compass.
Your are lucky you didn't end up like this guy (or worse):

 

[Whitwellian]

Your Phantom did not warn you that the compass was not calibrated. The compass does not lose calibration.
It was warning you that it detected a magnetic influence significantly different from the earth's normal magnetic field.
When you get this, recalibrating is the last thing you should consider doing.
The correct action is to simply move away from the magnetic distortion to a clean area.

There's no need to recalibrate a perfectly good compass.
Your are lucky you didn't end up like this guy (or worse):

The display indicated that there was a problem, which I took notice of. It had asked for a recalibration, which obviously didn't work.

I'm not daft enough to try a flight when a problem has been indicated, and I would never try a flight "just for the hell of it", and I'm glad that I was able to learn from what happened, yet remain safe.

One thing that my post, and all of the others in this selection reinforce is that everyone should heed what's displayed on the control App, learn from it and improve our knowledge to make sure that our Phantom remains safe and fully in our control.

 

[Meta4]

The display indicated that there was a problem, which I took notice of. It had asked for a recalibration, which obviously didn't work.
...
One thing that my post, and all of the others in this selection reinforce is that everyone should heed what's displayed on the control App

If you thought your app warned you to recalibrate it's poorly worded or you misunderstood.
Never attempt to recalibrate in an area close to iron, steel or electric cables.
To do so will cause problems.

 

[With The Birds]

Can you take off around magnetic interference and make a rapid climb out of it?

Yes you can, the compass will perform normally once you fly away from the structure that is causing the issue. Landing back where you launched from will be the potential problem. I often launch from and return to a 10" reinforced concrete suspended slab- hand catching is only option here.

 

[jephoto]

Can you take off around magnetic interference and make a rapid climb out of it?

Yes. If it is in fact the metal rebar in the concrete- Have someone hand hold the bird- both hands, one on each bottom landing gear over their head.
Start motors & should be able to take off from there.
I've also done this from the deck of a dinner cruise boat that was all metal.