DJI Spark launch RTH at high altitude and becomes unresponsive while showing inaccurate height

[cologne_seethe_mastery]

Hello,

First short introduction, i am brand new drone pilot, spark is my first ever drone i have owned and flied. First I was planning Mavic but though better start easier and upgrade later. I have had spark now about two weeks and keep learning and flying. Trying different setting everytime, recording and checking how it looks like.

Yesterday I was testing active tracking and trying to launch it first from palm and activate only using phone (usually Im always using RC) I initiate but kept getting error message aircraft too low even the drone was about 2-3 meters high (got distracted and forgot to check what display showed on screen) so I kept launching it while getting error message aircraft too low. Eventually I put it bit higher and got it to work (again unfortunately I did not read altitude on screen...)

After that I connected RC so easier controlling. I flew awhile and lifted drone about 30 meter and suddently RTH launched and could not move drone at all. It started to rapidly decent, got bit panicked. I was pressing pause on RC, pressing cancel on screen even hold RTH button on RC, trying to move sticks. Eventually pushing left stick forward got it stop. I was thinking hmmm what was that. I took drone down, changed battery and calibrated GPS and started to fly. Same thing happened when i got up past 30 meters. At that point I packed drone and called for the day. When I got back home I though IMU calibrate was needed so I did it.

Today I planned practise manual ISO, shutter speed and WB setting while manoeuvring tripod mode at low altitude (2-4 metres) Spark was acting perfectly, accurate and hovering very still (again did not check altitude on screen...) After a while I though I would do slow clime front of tree above treeline. Again around 30 metre mark RTH initiated. This time I did not panicked and eventually gain control of the plain. After I got plain safely back on my hand I went back home.

At home I connected my iphone to macbook so I could screen record. At provided video does not show GPS calibration but I did it before take off. I took drone off first to 30 meters and noticed altitude was not accurate, nothing happened. I took plain bit higher and according reading after 40 meter RTH came on. It was not even moving down. I should have speak while recording because I forgot sequence of pressed button.

I think first I pressed RC pause button-- nothing happened, then I pressed onscreen cancel---nothing then long press to RTH button on RC- nothing. Left stick up or down nothing but I was able to rotate as seen on video. After long pull left button aircraft started rapid decent. Pushing forward the left stick I got it to stop and safely on the ground.

Beginning the video i am showing my setting so you can check it if any of them are causing this. I appreacited any of your help if you need something else I will provide. I also like to thank many of you in this forum, I have learned a lot last 2 weeks in here.

app version 4.1.12
aircraft version 01.00.0600
flight database version 01.00.01.07
basic app fly safe database version 01.00.01.05
precise app fly safe database version 01.00.01.07

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[Buddy411]

At first glance, I'd say your barometer is wonky.

 

[Peter Powers]

What does the log say?

 

[V'lar]

My be a connection issue.
I would try using 2.4Ghz instead of 5.8.
Select 2.4GHz in the go app and select a free channel (one wihout a vertical bar), and wifi will reconnect. (At least on an iPhone).

 

[cologne_seethe_mastery]

Thanks guys your reply ! After reading your reply I went backyard to fly a bit. Buddy411 is right my barometre is wonky. I flied low altitude and it was not very accurate at all. Going 0.3 suddently to 3.6 even hovering. Went up over 30 meter but RTH did not launch. But flying few meters RTH did come on. Weird. Fortunately I found instructions how to extract flight data from aircraft and iphone. Not sure what to do with it..

I found this website DJI Flight Log Viewer and uploaded last flight data from iphone to there and looks understandable to read. Still does not give me much, maybe Peter Powers you could help a bit ? I can provide few readings to you:

during last flight i was connected 16-19 GPS satelite that might be good enough.

I will take few screenshots, please ask more if needed. I really appreaciate any help.

 

[cologne_seethe_mastery]

My be a connection issue.
I would try using 2.4Ghz instead of 5.8.
Select 2.4GHz in the go app and select a free channel (one wihout a vertical bar), and wifi will reconnect. (At least on an iPhone).

Did not see your reply, thanks. I will try that when someone comment my flight logs.

 

[Lastrexking]

Just as an aside - did you know you can record you screen activity directly in your iphone now (assuming you have ios11)?

 

[cologne_seethe_mastery]

Just as an aside - did you know you can record you screen activity directly in your iphone now (assuming you have ios11)?

yeah I know now, havent tried yet. I just googled how to screen record and found youtube video and this guy was recording using his macbook. When I did my screen record I found that you dont need to plug it to laptop... well learn that now.

 

[Lastrexking]

It works well. I used it last week whilst out flying my Spark.

 

[cologne_seethe_mastery]

My be a connection issue.
I would try using 2.4Ghz instead of 5.8.
Select 2.4GHz in the go app and select a free channel (one wihout a vertical bar), and wifi will reconnect. (At least on an iPhone).

after testing. I changed wifi settings to 2.4GHz and choose empty channel 10. Wi-fi rebooted and after that I did GPS calibrating. Started fly, might be placebo but it felt bit more accurate but looking flight log it wasnt. Atfer 1min 11,5sec of low flying RTH started (look screenshot forcelanding) aircraft was roughly 6m high when RC started to beep. I cancelled it by pushing left stick forward. Pretty soon I landed aircraft volunteery (look screenshot landingend) and you can see IMU altitude and VPS altitude are totally different as in every flight seconds but even when landed. I know what IMU is and I have calibrated it but I do not know what VPS altitude is ?

 

[cologne_seethe_mastery]

Ok, I am answering to myselve and writing in here in case someone has idea what to do. I did more testing. I even figured out what VPS altitude is ... so I cleaned all sensors below aircraft and front, calibrated IMU and GPS before flight. Wifi is back to 5.8GHz,does it comes automatic ? flying low altitude 1-3m its showing almost correct altitudes due to VPS altitude ? Anyway I figured out why its starting RTH on its own. When I climb up 10m-20m-30m altitude readings on my screen wobbles 0.3m (red colour) to its assumable currrent altitude ie. 35m. When I pull joystick down if its showing 35m aircraft reacts normally but because altitude wobbles around red 0.4m ie. if im pulling stick down aircraft thinks it close to ground and starts landing. Atleast now I know why RTH / landing starts automaticly. What next ? How can I get my altitude readings normal ? Should I do clean install on spark ? How about DJI should I contact them ? Many questions, what would you do ?