I was flying today and noticed something odd.
When I RTH Spark comes right back to where it took of.  If I fly out and then fly back using the track on the map Spark does not fly back to where it took off and I also note that if I then fly towards where the RC is shown on the map Spark comes nowhere near it. Also the landing posn and the RC posn are far apart on the map depsite being side by side on the ground!
Is this a compass calibration error?

Are you sure the home point is being recorded during the takeoff phase???

Rustic17 Posted at 2018-4-5 07:52
Are you sure the home point is being recorded during the takeoff phase???

Yes it says so - and in any event when I RTH it comes back spot on.

I think you found the perfect bug in DJI software ....

Hi there, may I know that have you refreshed the home point during the flight? If so, the drone will fly back to the new home point and won't fly back to where it take off. Regarding the landing position and the RC position are far apart on the map, could you please provide a photo? We'll look into it, thanks!

DJI Diana Posted at 2018-4-5 19:53
Hi there, may I know that have you refreshed the home point during the flight? If so, the drone will fly back to the new home point and won't fly back to where it take off. Regarding the landing position and the RC position are far apart on the map, could you please provide a photo? We'll look into it, thanks!

No did not refresh landing point.  Will fly later today (wind permitting) and I will get back to you.

Charliejspark Posted at 2018-4-5 23:16
No did not refresh landing point.  Will fly later today (wind permitting) and I will get back to you.

Ok, please try it again and keep us in updates, thanks!

You can also record it!

Can you upload the flight log for one of these flights where you've seen this behavior?  Instructions are on the following page.  Once you've uploaded, post the resulting URL here.  

http://www.phantomhelp.com/LogViewer/Upload/

Jerpie Posted at 2018-4-6 02:07
You can also record it!

That sounds very technical! Will see if I can.

KlooGee Posted at 2018-4-6 05:45
Can you upload the flight log for one of these flights where you've seen this behavior?  Instructions are on the following page.  Once you've uploaded, post the resulting URL here.  

http://www.phantomhelp.com/LogViewer/Upload/

Thanks will see what I can do.  No flying today wind far to strong.  

Sounds like a compass error.  A slight error, if you are flying back by dead reckoning and wind up off the expected point.  

Or, if that track is a series of GPS coordinates that make a line, then you are likely just looking at the error you get from the scale of the map you are using, the size of the phone screen you are using, and the thickness of the green line.  What looks like a smidge of the icon being off center of the course line on the map, on the tiny screen, translates to hundreds of feet in the real world.

RTH is using the actual GPS coordinates so it stay exactly on track where you are looking at an imprecise fat green line.

KlooGee Posted at 2018-4-6 05:45
Can you upload the flight log for one of these flights where you've seen this behavior?  Instructions are on the following page.  Once you've uploaded, post the resulting URL here.  

http://www.phantomhelp.com/LogViewer/Upload/

OK so here are two records.  I think the problem is on the 14--07-45 one towards if not at the end.

https://drive.google.com/drive/f ... zKRgCUj?usp=sharing

Hope this works - all a bit beyond me!  Still no flying - blowing a hooley.

DJI Diana Posted at 2018-4-5 23:45
Ok, please try it again and keep us in updates, thanks!

I could not upload a short video showing part of the problem.
the link is here
https://drive.google.com/drive/f ... nvW1hTJCMqAZzKRgCUj

Video

Any further thoughts?
Charles

Ok, first:
Install a screenrecorder, please ;-)
https://play.google.com/store/ap ... y929.screenrecorder

Second: The homepoint ist JUST UNDER your red triangle, it is the Tip of the green ballon, not the green ballon itself!

To the blue point: Has your RC GPS on?
Or is it 'only' A-GPS from the cell-network?

S-e-ven Posted at 2018-4-10 09:48
Ok, first:
Install a screenrecorder, please ;-)
https://play.google.com/store/ap ... y929.screenrecorder

S-e-ven thanks very helpful.  Yes I did know that the home point was the tip!
I did not know that you could switch the RC GPS on or off.  Its as it came out of the box and I have no idea of its status.
Will look at the screen recorder.

The RC has no GPS.
It needs the Location data from the Phone.
In case you wanna set the Homepoint to the RC, you need to have GPS on, on the device.
I assume, A-Gps alone ( location based on cellphone towers) can get you in a 'moving' RC location.
But it is a assumption, right now

Ah will check that out. Am sure GPS is on. There more to this than just flying isn't there

S-e-ven Posted at 2018-4-10 11:12
The RC has no GPS.
It needs the Location data from the Phone.
In case you wanna set the Homepoint to the RC, you need to have GPS on, on the device.

The tablet GPS is on.

Yesterday, I rode my bicycle in China, Shenzhen. In the middle of my day long ride, the Garmin bicycle GPS unit (Garmin Edge 1000) showed wrong GPS positions for nearly an hour. I suspected there might be some kind of GPS interference either by Government or by some natural causes. Is it related to the electronic GPS jamming war between the US/Russia/China during Syria crisis??  I am not sure.
Fortunately, I did not fly my Spark that day. Otherwise, I may lose my Spark if I press RTH. Dji Experts please advise on this issue.

DJI Diana Posted at 2018-4-5 23:45
Ok, please try it again and keep us in updates, thanks!

Roving RCS
OK as suggested here is a screenrecorder of one of the problems. The RCS is static on three RTH point but if you move the map it goes all over the place.
Hope I have the link right as not quite sure how to do it - sorry.

As others have mentioned, the RC doesn't have a GPS module of its own.  It is fully dependent upon the phone/tablet for GPS.  I'm not familiar with the particular tablet you have, but I know that the WiFi only iPad does not have a GPS module in it.  It is only the cellular version of the iPad that GPS built into it.  As I mentioned, I don't know the particulars of your tablet, but is it possible that yours doesn't have GPS in it?

KlooGee Posted at 2018-4-16 12:09
As others have mentioned, the RC doesn't have a GPS module of its own.  It is fully dependent upon the phone/tablet for GPS.  I'm not familiar with the particular tablet you have, but I know that the WiFi only iPad does not have a GPS module in it.  It is only the cellular version of the iPad that GPS built into it.  As I mentioned, I don't know the particulars of your tablet, but is it possible that yours doesn't have GPS in it?

The tablet must have a GPS as I use it for hiking, yatch ing and general navigation. Would it be because I have gone back to 4.1.15 and OTG as the WiFi connection just had too much lag and was very unstable.?

KlooGee Posted at 2018-4-16 12:09
As others have mentioned, the RC doesn't have a GPS module of its own.  It is fully dependent upon the phone/tablet for GPS.  I'm not familiar with the particular tablet you have, but I know that the WiFi only iPad does not have a GPS module in it.  It is only the cellular version of the iPad that GPS built into it.  As I mentioned, I don't know the particulars of your tablet, but is it possible that yours doesn't have GPS in it?

Much enjoy your youtube videos by the way.

Charliejspark Posted at 2018-4-17 00:48
The tablet must have a GPS as I use it for hiking, yatch ing and general navigation. Would it be because I have gone back to 4.1.15 and OTG as the WiFi connection just had too much lag and was very unstable.?

If you use it for other location based navigating purposes, it does sound like it has a GPS in it.  Not sure about whether it could be related to 4.1.15 or not.  Keep an eye out for 4.2.12 that is starting to roll out now for Android.  There are some rumors that it has fixed the Android OTG situation.  So far it seems like a small number of users that have gotten access to it, but something to keep an eye out for over the next days or week to see if it is true or not.

I wish I had a definitive answer for you on your query.  Best of luck in finding a resolution.

KlooGee Posted at 2018-4-17 04:57
If you use it for other location based navigating purposes, it does sound like it has a GPS in it.  Not sure about whether it could be related to 4.1.15 or not.  Keep an eye out for 4.2.12 that is starting to roll out now for Android.  There are some rumors that it has fixed the Android OTG situation.  So far it seems like a small number of users that have gotten access to it, but something to keep an eye out for over the next days or week to see if it is true or not.

I wish I had a definitive answer for you on your query.  Best of luck in finding a resolution.

Yes i see on other Spark forum that 4.1.12 now resolves the OTG problem Those that have tried it are very pleased. Not yet available in UK.
Will continue to work on other problem.
Thanks for your help