Aircraft position is opposite display readout

[Chrislaf]

Today I was flying my P3S using Litchi as I normally do. I took a panorama and a few other shots and the AC was responding as it normally does to stick inputs. I noticed that the little map that shows the direction the AC is pointing and the green line showing the distance from the Home point were opposite the actual position of the AC. It was like the map was a reflection in a mirror where everything is opposite. I brought the AC back and landed - didn't want to take any chances. I recalibrated the compass and launched GO to see if it was the same and again everything was opposite. Any ideas what is going on? I was not near any metal objects - was near a riverbank in a wetlands area so there shouldn't have been any interference.

Yesterday, I was at another location (an old railroad trail that has been converted to a walking trail) and was about 50m from some shipping containers. As soon as I powered on the RC and AC I got a compass error, so I abandoned flying from that location and packed up and left. I did try recalibrating the compass there but I just got another compass error. Could this have messed up my compass? Before yesterday everything was fine - the aircraft position was correct.

 

[Oso]

As soon as I powered on the RC and AC I got a compass error, so I abandoned flying from that location and packed up and left. I did try recalibrating the compass there but I just got another compass error. Could this have messed up my compass?

Am I understanding correctly that you tried to calibrate your compass in a magnetically influenced location which had just given you a compass error?

I urge you to NOT fly again until you re-calibrate your compass in a wide open area which is not magnetically influenced. This should reestablish a good baseline calibration. Then leave your compass alone from that point onward.

In the future, if you get a compass error just move to another spot without recalibrating.

Also, forgive me in advance if I've misunderstood your first post.

 

[Chrislaf]

Am I understanding correctly that you tried to calibrate your compass in a magnetically influenced location which had just given you a compass error? If so, then yes that could be a contributing factor to your compass issues.

I urge you to NOT fly again until you recalibrate your compass in a wide open area which is not magnetically influenced. Then leave your compass alone.

In the future, know that a "successful" compass calibration in a bad (magnetically influened) area is pretty high up on the list of what not to do. If you get a compass error, just move to another spot without recalibrating.

Also, forgive me in advance if I've misunderstood your first post.

Oso,
Thanks for your reply. Yes I tried to calibrate the compass when I got the compass error before takeoff but it failed and I abandoned the flight. In hindsight, I should not have tried to recalibrate there. At the time I did not think that I was in a magnetically influenced location. The rail trail is an old railway line that has been converted into a biking/walking trail. There are no rails or any remnants of the rail line left as it was all cleared. The shipping containers were off in a field surrounded by bush and were about 50-100m away so I didn't think they would have any effect unless I flew near them.

Regardless, tonight I flew two short flights at a location I have flown many times. I calibrated the compass and there were no errors. Used Litchi on the first flight and again the small google map was a mirror image of the aircraft location and direction. Aside from the mirror image on the google map everything else worked perfectly. I kept the AC close by landed and launched again in GO. Everything in GO worked perfectly and the AC location and orientation were correct throughout the short flight.

I will check my settings again in Litchi - maybe there is something that is not set correctly that is causing the google map view to be a mirror image. I am beginning to think the compass error had nothing to do with the Litchi problem since GO is working fine.

 

[Neon Euc]

Just another thought. Did you accidentally hit "headless mode" at some point in the settings? But like Oso said.... Redo a calibration in an open field

 

[epicdoom]

Oso,
Thanks for your reply. Yes I tried to calibrate the compass when I got the compass error before takeoff but it failed and I abandoned the flight. In hindsight, I should not have tried to recalibrate there. At the time I did not think that I was in a magnetically influenced location. The rail trail is an old railway line that has been converted into a biking/walking trail. There are no rails or any remnants of the rail line left as it was all cleared. The shipping containers were off in a field surrounded by bush and were about 50-100m away so I didn't think they would have any effect unless I flew near them.

Regardless, tonight I flew two short flights at a location I have flown many times. I calibrated the compass and there were no errors. Used Litchi on the first flight and again the small google map was a mirror image of the aircraft location and direction. Aside from the mirror image on the google map everything else worked perfectly. I kept the AC close by landed and launched again in GO. Everything in GO worked perfectly and the AC location and orientation were correct throughout the short flight.

I will check my settings again in Litchi - maybe there is something that is not set correctly that is causing the google map view to be a mirror image. I am beginning to think the compass error had nothing to do with the Litchi problem since GO is working fine.

one thing I know for sure Brother is no place that was something else at some point is completely clean of something from that time period. I am a metal Detecting hobbyist and I find stuff on old home sites from the 1700s that were cleared many years ago there is always something left behind. in a railway it could be buried railroad nails, track spike plates, coupling devices, railroad spikes even old locks and wheel bearings all of which would be magnetic type metals. I hope you get it figured out, I don't use Litchi so I'm of no help in that regard..

 

[Chrislaf]

Just another thought. Did you accidentally hit "headless mode" at some point in the settings? But like Oso said.... Redo a calibration in an open field

Thanks for your reply. I can't find headless mode in Litchi on my iPhone. Do you mean Course Lock or Home Lock. Regardless neither of these should affect how the map view displays the AC heading as it should reflect the actual position of the AC.

What I am worried about is if I do a waypoint mission and set up my waypoints for where the AC is to point will this problem affect the waypoint settings and be opposite? Anyway may fly in GO for the time being until I can figure this out.

 

[Neon Euc]

You made a good point actually about the arrow pointing in the opposite direction regardless of headless mode. OK scrap my last comment.... I would recommend doing a few things if recalibration doesn't work

1) delete DJI go app and then go to settings, folders, and delete them too. Even if you delete the app, the folders will remain in your phone saving all the settings. This could be whats causing the issue

Once you deleted the files reboot the phone/tablet and try to see if it works

2) if it doesn't work reflash the firmware again. You may need to downgrade and then upgrade... However I heard some people can brick their drones so its the very last option I would take. But try to delete the folders to start off with

 

[Chrislaf]

You made a good point actually about the arrow pointing in the opposite direction regardless of headless mode. OK scrap my last comment.... I would recommend doing a few things if recalibration doesn't work

1) delete DJI go app and then go to settings, folders, and delete them too. Even if you delete the app, the folders will remain in your phone saving all the settings. This could be whats causing the issue
View attachment 88008
Once you deleted the files reboot the phone/tablet and try to see if it works

2) if it doesn't work reflash the firmware again. You may need to downgrade and then upgrade... However I heard some people can brick their drones so its the very last option I would take. But try to delete the folders to start off with

Thanks for your suggestions.
My DJI GO app is displaying AC direction properly and everything is working fine. I'm hesitant to delete it and re-install (I'm on iPhone 7) if everything is working. I'm only having problems with the map display in Litchi. Everything else works perfectly. I don't think the problem is a calibration issue as it would be present in DJI GO as well. I already tried resetting all the settings in Litchi and that didn't work. I may try uninstalling then re-installing Litchi to see if that helps.

 

[Chrislaf]

Also, Airdata shows the correct flight paths for all my flights and no errors or warnings.

 

[Neon Euc]

Thanks for your suggestions.
My DJI GO app is displaying AC direction properly and everything is working fine. I'm hesitant to delete it and re-install (I'm on iPhone 7) if everything is working. I'm only having problems with the map display in Litchi. Everything else works perfectly. I don't think the problem is a calibration issue as it would be present in DJI GO as well. I already tried resetting all the settings in Litchi and that didn't work. I may try uninstalling then re-installing Litchi to see if that helps.

Ah OK. I didn't realise its on iOS and not android lol my mistake. But glad to see its working on DJI GO but I would delete litchi and reinstall it to be honest. All your litchi settings like max height and such is actually taken from DJI go so you wont have to do much setting up at all to be honest

 

[Chrislaf]

Ah OK. I didn't realise its on iOS and not android lol my mistake. But glad to see its working on DJI GO but I would delete litchi and reinstall it to be honest. All your litchi settings like max height and such is actually taken from DJI go so you wont have to do much setting up at all to be honest

Thanks for trying to help. I appreciate it. I deleted and re-installed Litchi. I will try to get out for a flight tomorrow to see if things are back to normal.

 

[Goatman1]

Have you touched the arrow on the upper right of the screen. I leave it pointing up(north is always at the top) but if you push it it allows you to view the screen relative to the position of the Android.

 

[Chrislaf]

Could have but since I have deleted and re-installed Litchi it should be back at defaults. I'm hoping to get out for a flight tomorrow to check it out.

 

[Chrislaf]

Today I did three flights - 2 with GO and one with Litchi. In both GO flights the AC icon matched the aircraft orientation. The AC orientation shown in the google map window in the Litchi flight was more accurate but still off and not spot on like the GO app. At least it wasn't a mirror image. I'm puzzled why its like this. Its more of a problem when I'm further out because its harder to determine AC orientation by VLOS. I may email Litchi to see what they have to say.

 

[Chrislaf]

Goatman
Thanks, that was my problem. I couldn't see the arrow initially since it's not in the small little google map window but soon as you make it full screen, it's there. Now everything os the way I want it. Found it harder to navigate when the map only points north especially when you are at a distance and can't tell the orientation without looking at the map.

I love Litchi and this was beginning to bother me, so thanks again.

 

[RodPad]

So, your fixed?
Nobody brought up anything about compass calibration on your mobile device, guess it wasn't the problem, I wasn't sure if your were using the same mobile device for Litchi and Go.

Anyways, here is good thread on compass calibrations.
Compass Calibration, A Complete Primer

Rod

 

[Chrislaf]

So, your fixed?
Nobody brought up anything about compass calibration on your mobile device, guess it wasn't the problem, I wasn't sure if your were using the same mobile device for Litchi and Go.

Anyways, here is good thread on compass calibrations.
Compass Calibration, A Complete Primer

Rod

Yes, it was what Goatman said. The little aircraft arrow on the Google map can toggle whether map is always looking North or relative to device (in my case iphone 7). Its not visible in the mini view which I always use, only when you maximize the map. I like it to show aircraft direction relative my device.

The compass error I only got that one time and didn't fly then. It was obviously unrelated to the Litchi problem. Anyway happy everthing is back to normal as I use the pano function in Litchi almost everytime I fly.

Chris

 

[rodgerbwg]

Today I was flying my P3S using Litchi as I normally do. I took a panorama and a few other shots and the AC was responding as it normally does to stick inputs. I noticed that the little map that shows the direction the AC is pointing and the green line showing the distance from the Home point were opposite the actual position of the AC. It was like the map was a reflection in a mirror where everything is opposite. I brought the AC back and landed - didn't want to take any chances. I recalibrated the compass and launched GO to see if it was the same and again everything was opposite. Any ideas what is going on? I was not near any metal objects - was near a riverbank in a wetlands area so there shouldn't have been any interference.

Yesterday, I was at another location (an old railroad trail that has been converted to a walking trail) and was about 50m from some shipping containers. As soon as I powered on the RC and AC I got a compass error, so I abandoned flying from that location and packed up and left. I did try recalibrating the compass there but I just got another compass error. Could this have messed up my compass? Before yesterday everything was fine - the aircraft position was correct.

I went through this myself. If memory serves there is a tab that orients the map. I think it is in the lower right corner.