Mavic Pro Compass errors in app

[Diederik]

I know it is something small most likely and I am most likely looking at the problem but not seeing it.

After days of researching, reading all forums, this one, Rc Groups and some others I still do not have an answer. I have checked the hardware inside, everything is connected, no broken wires on the GPS or compass. Drone has done 25 flights in total.

I have been flying and working with DJI products since the Phantom 1.

I recently bought a Mavic Pro. I know what causes magnetic interference, I do not do compass calibrations all the time, IMU and gimbal is calibrated, all firmware is up to date. I have taken off from different locations and the list goes on. Open spaces, built up area. I have many different DJI Drones, running N3 flight systems, naza fc. I think I have a good knowledge of the DJI Drones , software and hardware. (currently busy with a tethered drone running N3 with LB and a Zenmuse Z3, it will stay up in the air the whole day, busy with test flights)

I use a Samsung 7 Edge.

I am constantly getting compass errors in the app while flying, easily one every 30 seconds. They messages shows for 3 -5 seconds and is gone again. This does not affect flight at all, not when flying in normal or sport mode, not when using RTH (In RTH it shows most the time).

I have checked the flight logs, 13 - 14 satellites all the time, not a single error in any flight log for the past 5 days since I bought this MP.

I still fly it as per normal but I do not like getting this message all the time.

 

[SpinItUp]

I use a Samsung 7 Edge.

your phone! have you got another device to try?

 

[Diederik]

your phone! have you got another device to try?

As I was typing this I was thinking the same, that is the only thing I have not tried. i am going to load the GO4 app om my sons Note 4 quickly and see what happens.

 

[Diederik]

No it is not the phone. I think I must just go and replace compass 1 but I will first check with DJI warranty. It is all green while hovering but as soon as you accelerate it starts going right, becomes orange and then tells you that if the problem persists to contact DJI.

 

[Diederik]

Ok, further to this. i went to my friends the SA dji importers and spoke to the owner who is a certified DJI technician. He confirmed that I followed all the correct protocols as he would have done and that I should try a new GPS unit. We fitted a brand new one but with the new one the drone immediately gives a solid red light, we tried a second one, same story, it just gives a message "Navigation system error, check redundancy state" and no matter what we do the error does not go away.

He eventually also gave up and said that besides starting to replace all parts he does not know. We eventually ended up putting mu old GPS unit back. At least I can fly with hte old one.

One thing I did notice and I do not know if it has any relevance. The printer numbers on the pc boards of the 2 gps differ from each other. Mine has P01559.10.TCX-M 1636 printed on the back while the new has P01559.10.SH 174 1. printed on the back. When I look as pictures on the net most have the last 4 as 1740?

Anybody?

 

[Dragonfly]

Ok, further to this. i went to my friends the SA dji importers and spoke to the owner who is a certified DJI technician. He confirmed that I followed all the correct protocols as he would have done and that I should try a new GPS unit. We fitted a brand new one but with the new one the drone immediately gives a solid red light, we tried a second one, same story, it just gives a message "Navigation system error, check redundancy state" and no matter what we do the error does not go away.

He eventually also gave up and said that besides starting to replace all parts he does not know. We eventually ended up putting mu old GPS unit back. At least I can fly with hte old one.

One thing I did notice and I do not know if it has any relevance. The printer numbers on the pc boards of the 2 gps differ from each other. Mine has P01559.10.TCX-M 1636 printed on the back while the new has P01559.10.SH 174 1. printed on the back. When I look as pictures on the net most have the last 4 as 1740?

Anybody?

Hi Diederik, your problem is not your compass, it is fine. What it is occurred in earlier Mavics and has to do with the wires from the rear motor and where they enter from the inside of the leg in the Mavic to the circuit board. The three wires should be well twisted to stop any interference from the motor under revs. In some early Mavics the wire were not twisted or not enough twists and stray electrical interfernce from motor revs caused magnetic interference to the the closeby no1 compass at rear of aircraft.
This caused the message you see in Go4 app.
The fix was just to undo the three(3)screws that hold the leg in place and put some more twists in wires before screwing back in place. It was common for back left leg to be one at fault when looking at back of aircraft. But would do both to be sure.
PS. You have to remove top shell to remove back leg.

 

[Diederik]

Hi Diederik, your problem is not your compass, it is fine. What it is occurred in earlier Mavics and has to do with the wires from the rear motor and where they enter from the inside of the leg in the Mavic to the circuit board. The three wires should be well twisted to stop any interference from the motor under revs. In some early Mavics the wire were not twisted or not enough twists and stray electrical interfernce from motor revs caused magnetic interference to the the closeby no1 compass at rear of aircraft.
This caused the message you see in Go4 app.
The fix was just to undo the three(3)screws that hold the leg in place and put some more twists in wires before screwing back in place. It was common for back left leg to be one at fault when looking at back of aircraft. But would do both to be sure.
PS. You have to remove top shell to remove back leg.

Thank you for your response on Facebook, i will post later today here as well.

 

[Former Member]

Its still O'dark thirty here in Atlanta, but I will take a stab at this.

The drone works and lets you fly, but you get compass error messages as you fly. You are not getting the toilet bowl effect, which is a good thing. It is possible that the compass error messages themselves might be erroneous and the app, firmware or FC board are the problem. As @Dragonfly mentioned, there were a few magnetic interference problems in the early Mavics made before December 2017 with the wires going from the left rear leg disorienting the compass, but those errors effected compass #1. You need to pinpoint which compass is giving you the error.

You can try to take off, as soon as you take off, open the compass sensor window,. It will give you readings for both compasses and their respective signal strengths. Fly as normal and then where the app shows a compass error, verify which compass is generating the error. The deviant compass will probably be in the red, and the other in the green. If that were not the case, and both compasses were in the red, the drone would toilet bowl instead of flash an error message. When you do open the compass window, if neither of the compasses shows in the red while the app shows compass error, then it is either an app, firmware or FC board problem.

After you verify which compass is the problem, if either, is giving you the problem, you can post the results up here.

 

[Diederik]

HI Thunderdrones.

It is compass one that starts giving error mesagges once you accelerate and then disconnects for a couple of seconds or until you stop accelarating. Compass 2 sees to it that the craft remains where it is supposed to be.

I am going to open the craft just now and twist the wires and see what happens. I have some work things to get done and will then tackle the Mavic . As I said to Dragonfly, i will report back once I have flown again.

Just as a side note, i flew just now to take photographs of a fire claim I am busy with, spend around 13 minutes in the air with moderate wind and gusts and it was as stable as it should be but error messages as soon as the wind gusts appear or when I accelerate.

 

[BudWalker]

HI Thinderdrones.

It is compass one that starts giving error messages once you accelerate and then disconnects for a couple of seconds or until you stop accelerating. Compass 2 sees to it that the craft remains where it is supposed to be.

I am going to open the craft just now and twist the wires and see what happens. I have some work things to get done and will then tackle the Mavic . As I said to Dragonfly, i will report back once I have flown again.

Just as a side note, i flew just now to take photographs of a fire claim I am busy with, spend around 13 minutes in the air with moderate wind and gusts and it was as stable as it should be but error messages as soon as the wind gusts appear or when I accelerate.

Before you go to the trouble of opening the Mavic we should take a look at the .DAT log. It'll be obvious if it's the motor-wire-aren't-twisted-enough problem. That problem was "fixed" by DJI with a firmware release that silently switches to compass 2.

"Compass Error" is a catch all error message that can be due to other things besides the compass itself. The .DAT will help here. The AC .DAT would be best, look here. But, depending on the FW version it may not be available. In that case the tablet .DAT would be OK. Look here for that.

 

[Diederik]

Dragon fly a big thank you.

Thank you very much for your advice. There was not a single twist in either the left or the right rear motor wires. Now they have a lot of twists in them. Took it for a 5 minute flight after calibrating the compass with a lot of wind gusts, had the compass part of the app open and compass 1 was rock solid. No error massages like earlier today flying in the same conditions. Again thank you and thank you for saving me R1000. Dji SA has already processed the refund.

 

[Diederik]

Before you go to the trouble of opening the Mavic we should take a look at the .DAT log. It'll be obvious if it's the motor-wire-aren't-twisted-enough problem. That problem was "fixed" by DJI with a firmware release that silently switches to compass 2.

"Compass Error" is a catch all error message that can be due to other things besides the compass itself. The .DAT will help here. The AC .DAT would be best, look here. But, depending on the FW version it may not be available. In that case the tablet .DAT would be OK. Look here for that.

I checked the log files, there was not a single error, that iw what was so strange to me, but it is sorted now. Thank you

 

[BudWalker]

I checked the log files, there was not a single error, that iw what was so strange to me, but it is sorted now. Thank you

I saw that you got it sorted. The untwisted-wires problem won't show up as an error per se. You have to look at the magnetometer data in conjunction with the motor current data. Can you post one of the .DATs?

 

[Diederik]

Of course Just have to get some oil (Parrafin is what we call it)to start my windows 7 computer, give a couple of minutes

 

[Diederik]

Be patient with me, my windows 7 machine reads no dat files, i do not see them om the card either.

i will have to install Itunes quickly, mind you Itunes will not work as I use a Samsung S7 Edge

 

[Diederik]

Here you go

I saw that you got it sorted. The untwisted-wires problem won't show up as an error per se. You have to look at the magnetometer data in conjunction with the motor current data. Can you post one of the .DATs?QUOTE]
18-10-10-10-03-12_FLY111.DAT

This is the file from my flight earliet today, plenty errors and some wind gusts etc

 

[BudWalker]

Here you go
This is the file from my flight earliet today, plenty errors and some wind gusts etc

Things have changed a lot from back when the untwisted motor wires caused noisy Z axis magnetometer data. Looking at your .DAT there isn't any indication of noise. But, there were several of these from the eventLog stream
32.516 : 4966 [L-FDI]NS(0) COMPASS(0): fault off, noise
32.896 : 4985 [L-FDI]NS(0) COMPASS(0): fault on , noise
that seem to coincide with the higher motor currents. You could check the .DAT for the successful flight.

Back then it was motor currents of around 20 amps, usually in Sport mode full throttle and/or elevator, that would cause the noisy mag data. Your .DAT only saw around 10 amps peak.

If you want to look closer we need the AC .DAT. The tablet .DAT only reports one mag, presumably the one that's being used. Also, the AC .DAT will show more info about the compass errors. But, it looks to me like you found the culprit.

 

[Diederik]

During this flight I never went full throttle at any stage, was scared as the errors become worse then, I just pushed her at around 20km/h. I cannot get the AC DAT. Assistant tells me there are no files to retrieve. I have been having this problem on windows. Sometimes windows also says there are no updates but when I then go to the app the updates are there.

Thank you for the effort, I appreciate it.

 

[BudWalker]

During this flight I never went full throttle at any stage, was scared as the errors become worse then, I just pushed her at around 20km/h. I cannot get the AC DAT. Assistant tells me there are no files to retrieve. I have been having this problem on windows. Sometimes windows also says there are no updates but when I then go to the app the updates are there.

Thank you for the effort, I appreciate it.

Do you know about these instructions
How to retrieve a V3 .DAT File from the AC

 

[Diederik]

Ok, makes sense, I am running version 1.1.2. I will find a link to a newer one, install and try again. thanks