Hi.

Flew a photo trip with my mavic this afternoon. The wind was so powerful that Mavic could achieve a top speed of 15 km/h with neutral stiks in GPS-P mode at 100 meters altitude. I have tried it so many times that I am used to it. What did not go well was I got some strange messages in the app and with the voise about Mavic switching to ATTI mode at the end of the flight. Likewise, there was a strange message about move to area 9 on the screen ??? I did not quite know what it meant when I obviously had my eyes on Mavic if she were to starting moving in the strong wind. Can see in my log I've had some Magnetic Filed Interference. Exit P-GPS Mode; Yaw Error and Compass Error. I wonder, however, because i am flying frequently in the area and have never experienced anything like that before with my Mavic. The Kp index was at 2 so I suppose it is not our mother's solar output.

The log is here:  http://www.phantomhelp.com/LogViewer/M9YHJ263HKS7HRRT3HFL/#

Comments on what happened are welcome so I can learn.

A thanks to PhantomHelp.com is sent for loans of their great program.

Regards Leif.

Hi Lief, just a few things i noticed and thought to mention.
1. check the duration of the Compass error notices throughout yr flight - it is 0.7 seconds; 2.1 seconds & 1.3 seconds - this does appear to be a problem - these are 3 short error messages that got quickly resolved.
2. Magnetic field interferance notice - 0.2 seconds - this happens apparently only once and for very short time - it is resolved and does not appear again. So although it probably gave you a fright to see, when put into perspective (ie it was an issue for 0.2 seconds out of 20+ min flight) - i personally would not be concerned about it.
3. It does appear that you might have been trying to enter sport mode - but failed. In order to do sport mode you must first enable "multiple flight modes" in the settings menu - it is good to have sport enabled if you are flying in the wind.
4. it appears you disabled the VPS? maybe because it was "avoiding obsticles on RTH" ?
5. Yaw issue - sorry i have no comments here. Would be interested to know what you find out about it.
6. Be careful of flying in the wind. if the wind picks up then i recommend that you fly up wind so that RTH is down wind.

Bekaru Tree Posted at 2017-9-11 11:57
Hi Lief, just a few things i noticed and thought to mention.
1. check the duration of the Compass error notices throughout yr flight - it is 0.7 seconds; 2.1 seconds & 1.3 seconds - this does appear to be a problem - these are 3 short error messages that got quickly resolved.
2. Magnetic field interferance notice - 0.2 seconds - this happens apparently only once and for very short time - it is resolved and does not appear again. So although it probably gave you a fright to see, when put into perspective (ie it was an issue for 0.2 seconds out of 20+ min flight) - i personally would not be concerned about it.

Thanks for reply.

1. That's what I'm having trouble because I've never seen a compas error before. Notice how high I am when they came and at the same time it is over open farmland.

2. Magnetic Filed Interference. Exit P-GPS Mode comes in the middle of a strip of Yaw Error and at the same time Mavic goes into ATTI mode for 10 seconds with 20 satellite locked. In the 10 sec Mavic drove 100 meters !!! Flying only in VLOS.

3. Yes sportsmode, LOL. There I forgot and get it turned on again the last time after a couple of grandchildren had been allowed to fly under my supervision. It does not mean anything here, because I can just go down at the ground if .....................................

4. No, VPS is actually ON. Otherwise, Mavic can not brake when auto landing on grass.

5. Yaw issue ?  The only explanation I would like to be is the wind that turns Mavic against its will ?

6. There are no problems here at the place where I fly. There is a priority 2 hvis is down if something unexpected happens as it is 99.99% farmland.

Forgot and write that both IMU and compass were quite normal at start and after landing.

Regards Leif.

Landbo Posted at 2017-9-11 13:00
Thanks for reply.

1. That's what I'm having trouble because I've never seen a compas error before. Notice how high I am when they came and at the same time it is over open farmland.

Yaw error or magnetic yaw as it should be usually followed by compass error and switch off of gps, reason this happens.

Why would a compass error disable GPS?
Orientation (compass data) and position (GPS data) are different but related.
When the Mavic is moving and getting position information from the GPS that tells the Mavic  that it is travelling in a different direction from what it's getting from compass data, The Mavic programming can't work with the data conflict.
The solution is to drop data from one source and since the Mavic can't fly without a compass but can without GPS, it's the GPS data that gets dropped.

There have been some compass problems with Mavic lately or your issue may have been related to something you done
I'd be curious about when and where you calibrated it and where you launched from as these may be relevant factors.

hallmark007 Posted at 2017-9-11 14:20
Yaw error or magnetic yaw as it should be usually followed by compass error and switch off of gps, reason this happens.

Why would a compass error disable GPS?

Thanks for reply.

Yes, which device is getting a wrong input, compass or GPS with a solid lock of 20 sattelites?

It is at least 100 flights since I've calibrated IMU and compass. Otherwise, I only calibrate when DJIGO4 tells me, which is near never. The green lines for both compass and IMU are short when I check them.

Regards Leif.

Landbo Posted at 2017-9-11 14:51
Thanks for reply.

Yes, which device is getting a wrong input, compass or GPS with a solid lock of 20 sattelites?

It looks like you had some geomagnetic interference whether you picked it up on the ground or somewhere else, but when this happens aircraft will always drop gps in favour of the compass, simply because you can't fly without compass but you can without gps, so aircraft goes to Atti mode.
Maybe someone can have a look at your Dat file and pick up what the reason for your compass problem.

Thanks for the answers above. And please try to calibrate the compass first and test in another place with less interference again. If the compass error persists and the drone always goes to ATTI mode, please report this case to our support team to start the data analysis. For the Yaw error, did you also get it on the DJI GO 4 app? If yes, could you please provide us with the screenshot of it? Coz I've never seen in before.

hallmark007 Posted at 2017-9-11 15:07
It looks like you had some geomagnetic interference whether you picked it up on the ground or somewhere else, but when this happens aircraft will always drop gps in favour of the compass, simply because you can't fly without compass but you can without gps, so aircraft goes to Atti mode.
Maybe someone can have a look at your Dat file and pick up what the reason for your compass problem.

Yes, geomagnetic interference can i not really be avoided when I fly out in the mother's nature. But the Kp index has not been higher than 2 in the time I was in the air, which is reasonably low.

I try and get my DAT file found, if there is someone who wants to comment on it.

Regards Leif.

hallmark007 Posted at 2017-9-11 15:07
It looks like you had some geomagnetic interference whether you picked it up on the ground or somewhere else, but when this happens aircraft will always drop gps in favour of the compass, simply because you can't fly without compass but you can without gps, so aircraft goes to Atti mode.
Maybe someone can have a look at your Dat file and pick up what the reason for your compass problem.

Link to my DAT file:  https://www.dropbox.com/s/04fo1m ... -17_FLY023.DAT?dl=0

Regards Leif.

DJI Thor Posted at 2017-9-11 19:56
Thanks for the answers above. And please try to calibrate the compass first and test in another place with less interference again. If the compass error persists and the drone always goes to ATTI mode, please report this case to our support team to start the data analysis. For the Yaw error, did you also get it on the DJI GO 4 app? If yes, could you please provide us with the screenshot of it? Coz I've never seen in before.

Hello great Thor, son of Odin and Earth.

May try and recalibrate compass. But the values are so great (short green lines) that the outcome can be worse than it is now.

Interference, I can not do anything about that because it comes from our mother sun.

I'll report if the error repeats.

There is no error message in DJIGO4 for Android when it happened. But when Mavic went to ATTI mode, there was a message I never has seen before, something with Mavic wanted to move to point/area 9, which I do not know what is (GEO rubbish ?). I do not see the message when I play the flight back again. And no, when I got the message about switching to ATTI mode I was busy of getting up to an height where my Mavic did not hit anything when it was drifting in the wind and not making image documentation about what happened, sorry !!!

Regards Leif.

Landbo Posted at 2017-9-11 22:14
Hello great Thor, son of Odin and Earth.

May try and recalibrate compass. But the values are so great (short green lines) that the outcome can be worse than it is now.

Thank you for getting back and looking forward to your feedback. Besides, I am sorry for that I couldn't totally understand your question about the Mavic wanted to move to point/area 9 on screen. Could you please provide me with more details so I can understand better? Appreciate it.

DJI Thor Posted at 2017-9-12 03:33
Thank you for getting back and looking forward to your feedback. Besides, I am sorry for that I couldn't totally understand your question about the Mavic wanted to move to point/area 9 on screen. Could you please provide me with more details so I can understand better? Appreciate it.

Unfortunately, I can not document the cryptic message I received since it is not in the log and does not appear when replaying the flight again. All I can tell is that the writing was on a white background and not a black that's normal when I have to unlock my hidden restricted area !!!

I can tell I was out and fly a trip here shortly before dinner In even more wind than it was yesterday. Chose not to calibrate my compass to see if I could get the same error again. But my Mavic behaved quite normal today. I suppose the shift to ATTI mode is due to a discharge from our mother sun.

Regards Leif.

Landbo Posted at 2017-9-11 21:05
Link to my DAT file:  https://www.dropbox.com/s/04fo1m ... -17_FLY023.DAT?dl=0

Regards Leif.

I think I will leave reading dat to those who study it, maybe droneflying might have a look for you.

hallmark007 Posted at 2017-9-12 07:07
I think I will leave reading dat to those who study it, maybe droneflying might have a look for you.

Yes hope it will happens, so I can become wiser on what happened. Thanks.

Regards Leif.

Landbo Posted at 2017-9-12 05:20
Unfortunately, I can not document the cryptic message I received since it is not in the log and does not appear when replaying the flight again. All I can tell is that the writing was on a white background and not a black that's normal when I have to unlock my hidden restricted area !!!

I can tell I was out and fly a trip here shortly before dinner In even more wind than it was yesterday. Chose not to calibrate my compass to see if I could get the same error again. But my Mavic behaved quite normal today. I suppose the shift to ATTI mode is due to a discharge from our mother sun.

Alright. Maybe take a screenshot if it happens again next time. So is the drone working well now? Glad to hear that. Should you have any further questions, please feel free to contact us at any time, we're glad to help.

DJI Thor Posted at 2017-9-14 02:54
Alright. Maybe take a screenshot if it happens again next time. So is the drone working well now? Glad to hear that. Should you have any further questions, please feel free to contact us at any time, we're glad to help.

No not today, but of a very different reason Thor, Post # 12:  http://forum.dji.com/forum.php?m ... 44&page=1#pid956190   
EDIT:  Thank you for hearing to how my Mavic behaves.  

Regards Leif.