Thought I post this, hoping it will help either me or someone else.

Just got a Spark back from repair after a minor crash (please see this thread)


The AC I got, seems to be the same as I sent in. atleast the S/N is the same, both on the styrofoam case and on the AC itself. Echanged parts were: 3x motors, 1x fan, 1x Gimbal roll & pitch axis module, 1x mid-frame and 1x main core processor board. Service center noted 'No GPS-Issue found during test'.


After activation I aimed to test it out, to see if it worked as it should. Unfortunately it didn't. I started it in beginner mode, and it wouldn't take off  because it shows 'No GPS'. The satellites are there, but it appears no connection/reception. I waited a long time to see if it would find any reception, but never did. I thought that the last place it had GPS connection in, should have been in the service center in the Netherlands. Atleast they said they performed a test flight. Thought that it could take some time for the AC to find it's new location.


Anyhow, even if it got good GPS, I wouldn't have taken off. It's picking up heavy compass interference, and this is in an area that really shouldn't have any metal close by.. I have tried in several different areas, I have made flights in those areas with this unit  before. I probably will try more areas later today.

Having read a bit about compass calibration here and in different forums, I didn't perform any. I had a Spark which I almost lost because of compass errors, so I'm a bit worried that if I calibrate, the problem may still persist but won't be showing until mid-flight. Grateful for any input here.

I have wrote the same representative that handled the initial repair case, and explained the situation. No reply yet.

I'm not sure what would be best doing in this situation.. Try the standards (flash firmware, downgrade/upgrade, restore factory defaults, calibrate the compass in open area, try even more different locations to see if I get GPS-reception..) or just ship it back to DJI for evaluation.

Also, can someone tell me if I can view the entries from the black box? There is 5-7 entries there which I think have been made during service. If they performed flight tests, the logs might be there and it would be interesting to see how it performed.

I tried in some different ways, but no luck yet..

Kind of sad, after having the AC in the repair shop for almost two months, I get it back with these errors, problems it never had before..

This is what the Go4 app is telling me:

You should calibrate the compass, in an area free of any magnetic interference, best to do it on a wooden table for example. It is a little weird that you have 13 satellites but 0 bars, did you fly in that area previously with good reception ?
As for the black box , you can access this from the DJI Assistant 2 app for windows, you can select "Data Upload", tick all the flight records and Save to local, i believe this creates 1 large DAT file repository which contains all the .DAT individual flights. If you post that to google drive i can take a look for you, if you would prefer to do it yourself you would need to extract the .DAT files from the repository and check the .DAT files with some software that can read them.

Ben Mason Posted at 10-11 02:45
It is a little weird that you have 13 satellites but 0 bars...

Its not weird, its logical since the compass does not deliver good values. Without a working compass, GPS satellite count numbers are of no use.

I'd also say: try to calibrate the compass first, do it as precisely as possible. If that doesn't help, reflash the firmware. You never know if they had some sort of test firmware on that bird while being in the support center.

Cheers,
Wolferl

Wolferl Posted at 10-11 05:29
Its not weird, its logical since the compass does not deliver good values. Without a working compass, GPS satellite count numbers are of no use.

I'd also say: try to calibrate the compass first, do it as precisely as possible. If that doesn't help, reflash the firmware. You never know if they had some sort of test firmware on that bird while being in the support center.

Yes it's correct that he would still have (No GPS) or exit GPS mode errors, because he has the compass error, but I'm fairly certain you can still have GPS signal bars and have compass error.

You'd think it'd be clear out on those rocks in that forest, but you never know. I had compass interference -- atti mode, and then compass interference, cannot take off in such a place. The rocks were reddish, must have been a lot of iron in them.

Hi Flygmaskin, we are so sorry for the difficulties with the drone, if the compass is interfered, the aircraft will also exit the P-GPS mode, please stay away from the magnetic interference, calibrate the compass in a different place. If the issue persists, flash the firmware.
Besides, may we have your previous case number?

Ben Mason Posted at 10-11 02:45
You should calibrate the compass, in an area free of any magnetic interference, best to do it on a wooden table for example. It is a little weird that you have 13 satellites but 0 bars, did you fly in that area previously with good reception ?
As for the black box , you can access this from the DJI Assistant 2 app for windows, you can select "Data Upload", tick all the flight records and Save to local, i believe this creates 1 large DAT file repository which contains all the .DAT individual flights. If you post that to google drive i can take a look for you, if you would prefer to do it yourself you would need to extract the .DAT files from the repository and check the .DAT files with some software that can read them.

Yes, I have flown in that area before, without problems. Both areas I tried actually.

I have tried reading the .dat files with various software without any luck.. It would be really nice of you (or anybody else, feel free) if you like to check them. There are five .dat files made on the AC from when it was in the service center. Some of these files should be from flight test (if they performed one that is). Would be interesting to see if there was any issues with compass or GPS.

I saved the files from the AC one by one and uploaded them to Google Drive. Please see the links here:


1
2
3
4
5

I will try calibrating the compass, but I will be super careful not to have any objects in proximity that might interfere. So I will do it outdoors, but been having real bad luck with the weather lately..

Wolferl Posted at 10-11 05:29
Its not weird, its logical since the compass does not deliver good values. Without a working compass, GPS satellite count numbers are of no use.

I'd also say: try to calibrate the compass first, do it as precisely as possible. If that doesn't help, reflash the firmware. You never know if they had some sort of test firmware on that bird while being in the support center.

I would have thought that the GPS still could get good satellite count and strong reception, regardless of compass issues. But once up in the air, any compass issues would drive the GPS mad, since they are not "reading the same numbers", thus exit GPS-mode and hello ATTI-mode.

We might see when I perform the compass calibration. I do hope that the problems are related so the compass interference is causing the reception problme on the GPS.

Firmware is the latest one according to Assistant 2.. But as you are saying, who knows what kind of FW they might have in the service centers..

Tentoes Posted at 10-11 16:08
You'd think it'd be clear out on those rocks in that forest, but you never know. I had compass interference -- atti mode, and then compass interference, cannot take off in such a place. The rocks were reddish, must have been a lot of iron in them.

Yes, one would think it would be all clear and good in that location.. Has been before anyway.

What seemed to cause the compass interference you experienced?

DJI Mindy Posted at 10-11 23:52
Hi Flygmaskin, we are so sorry for the difficulties with the drone, if the compass is interfered, the aircraft will also exit the P-GPS mode, please stay away from the magnetic interference, calibrate the compass in a different place. If the issue persists, flash the firmware.
Besides, may we have your previous case number?

Thank you, I will perform a compass calibration as soon as the weather improves and the rain stops.

Yes, I'm a bit sorry as well. Having been without the Spark for a long time, and when it returns, it's stuck with these errors..

I will send the case number in PM to you. Any information would be appreciated!

Maybe it's the same issue I had here except for the compass error. If so, the GPS will fix itself after a while. Not so sure about the compass...

Good luck.

Flygmaskin Posted at 10-13 13:22
Thank you, I will perform a compass calibration as soon as the weather improves and the rain stops.

Yes, I'm a bit sorry as well. Having been without the Spark for a long time, and when it returns, it's stuck with these errors..

PM has been received, it is recommended to calibrate the compass when the DJI Go 4 APP prompt you to do so, please have a try and keep us updated.

Flygmaskin Posted at 10-13 13:15
Yes, I have flown in that area before, without problems. Both areas I tried actually.

I have tried reading the .dat files with various software without any luck.. It would be really nice of you (or anybody else, feel free) if you like to check them. There are five .dat files made on the AC from when it was in the service center. Some of these files should be from flight test (if they performed one that is). Would be interesting to see if there was any issues with compass or GPS.

I sent you a PM about the flight records.