Need some help with cause for signal/control problems

[Chrislaf]

Today I was out flying my P3S at two locations I have flown before (one many times) and I had lots of signal problems and temporary loss of control for both flights. I cut both flights short because I didn't want to loose control of the craft. I also want to see if I can figure out what the problem was so I can prevent this from happening again. Landed AC without problems in both flights.

The first flight was in a heavily treed area and although I have flown there before, I thought the problems were due to signal being blocked by trees, although the AC was in sight and above the trees. The second flight was at a beach and the AC was close by and within sight with nothing blocking the signal. Both flights I had started a pano in Litchi and the AC disconnected and began to drift (atti mode?). On the second flight when the AC disconnected at one point it seemed like I had no control temporarily and the AC began to drift. Also, when I used auto take-off nothing happened for a few seconds so I closed Litchi but then the AC took off. I re-launched Litchi and it reconnected a few seconds later. On both flights the video signal was lagging and choppy even though the AC was close by.

The temperature was between -7 and -8ºC and winds were light, around 4km/h. My batteries were warmed beforehand and I have flown in colder weather than this without any problems.

Here are the Litchi csv flight logs in case anyone wants to take a look. Let me know if I'm not doing it right as this is my first time posting the flight logs. One thing I noticed is on the second flight at the beach, the point where I launched is wrong on the Google map. I launched more toward the beach and near the lifeguard tower.

Forest Flight
Dropbox - 2017-12-21_10-54-22_v2.csv

Beach Flight
Dropbox - 2017-12-21_11-57-55_v2.csv

Thanks in advance for any help.

Chris

 

[Chrislaf]

Sorry, I think I did this wrong. Here are the links to the results in the Log viewer:

Forest Flight
DJI Flight Log Viewer - PhantomHelp.com

Beach Flight
DJI Flight Log Viewer - PhantomHelp.com

Chris

 

[stuka75]

Be sure that either LItchi or DJI Go app have been force stopped prior to using either for flying if on same device. IN Android for sure. Once opened either program remains in memory unless force stopped in the apps section of "Setting" menu frequently causing erratic control/telemetry. And, I have noticed that occasionally same day flights with different batteries need to have the Go program force stopped between flights and batteries to clear up issues. Force stopping any flight program on your device prior to or when having problems is a good idea and can help rule out program to program interference.

 

[stuka75]

If using a tablet to fly, be sure your phones wifi is turned off.

 

[Chrislaf]

Be sure that either LItchi or DJI Go app have been force stopped prior to using either for flying if on same device. IN Android for sure. Once opened either program remains in memory unless force stopped in the apps section of "Setting" menu frequently causing erratic control/telemetry. And, I have noticed that occasionally same day flights with different batteries need to have the Go program force stopped between flights and batteries to clear up issues. Force stopping any flight program on your device prior to or when having problems is a good idea and can help rule out program to program interference.

Thanks for your reply. I only had Litchi running, GO was closed. I always only run with one app running. I’m on iOS.

I’m wondering if it could be related to firmware. I’m running latest Litchi and GO apps but not firmware. I have been hesitant to update due to all the problems I read about. Now that I have a Spark under the Christmas tree, if I run into problems on my P3S at least I won’t be droneless.

 

[Chrislaf]

If using a tablet to fly, be sure your phones wifi is turned off.

I use my iphone 7 and always fly in Airplane mode.

 

[Chrislaf]

Edit: Accidentally grabbed wrong flight record for Forest flight. Fixed it in link above. Map does show correct location.

Here is the shared Airdata links which show the correct map and home points for each flight

Forest Flight
Airdata UAV - Flight Data Analysis for Drones

Beach Flight
Airdata UAV - Flight Data Analysis for Drones

Not sure why the Flight Log Viewer and Airdata maps are different but the Airdata ones are accurate for the flights. Disregard this - my error. Maps are the same in both Airdata and phantom log viewer.

I looked at my flight on Saturday in the Flight Log viewer and the map displayed is accurate for that flight. That flight was on a much colder day and I had no problems with signal or control.

 

[stuka75]

The data points to a clear issue with the telemetry as you stated. The poor sensor signals are a known error with Litchi as I get same sensor data, but perfect if flown with Go app same day, same battery etc. You were wise to abort the flights early.
that said I will bow out as Im on Android and other on IOS should step in. Again I wonder if iphone has similar way of force stopping apps.
Try flying with the Go app and see how things behave. I do know that recent version of Litchi required more RAM and I had to get a newer tablet to fly. This was verified by Litchi developers themselves. Not sure where your iphone fits in with that.
Good luck and keep us informed.

 

[Chrislaf]

The data points to a clear issue with the telemetry as you stated. The poor sensor signals are a known error with Litchi as I get same sensor data, but perfect if flown with Go app same day, same battery etc. You were wise to abort the flights early.
that said I will bow out as Im on Android and other on IOS should step in. Again I wonder if iphone has similar way of force stopping apps.
Try flying with the Go app and see how things behave. I do know that recent version of Litchi required more RAM and I had to get a newer tablet to fly. This was verified by Litchi developers themselves. Not sure where your iphone fits in with that.
Good luck and keep us informed.

Thanks for your reply. I will try just GO next time I’m out and see how it goes. Don’t think my iphone 7 is the problem - it has the current iOS and lots of space. RAM shouldn’t be a problem as I have been using it for every flight taken on my P3S.

 

[RodPad]

Is this the correct one?
DJI Flight Log Viewer - PhantomHelp.com

Sorry no answers, I use IOS, never had problems with Litchi / Go conflicting, of coarse I don't have them operating at the same time, and I know about the Android (kill app) procedure.

Yeah, this is some pretty poor signals.

Rod

 

[Chrislaf]

Is this the correct one?
DJI Flight Log Viewer - PhantomHelp.com

Sorry no answers, I use IOS, never had problems with Litchi / Go conflicting, of coarse I don't have them operating at the same time, and I know about the Android (kill app) procedure.

Yeah, this pretty poor signals.

Rod

Yes, sorry for the confusion. I use iOS too and up until today I have never had any problems with Litchi.

 

[Chrislaf]

I updated my firmware on my P3S last night and the update completed without any problems, so now everything is current - AC firmware, GO and Litchi. Hopefully I won’t have the signal/control problems again now that there is no mismatch in control software and hardware firmware. Will have to wait for a better day weather wise to test it out.

Chris

 

[Chrislaf]

Today, I finally got out again to fly my P3S. Everything went ok and I did not have any of the signal loss or control problems I had the other day. On the flights where I had signal/control problems, I had been using my new transmitter glove to keep my hands warm. It completely covers the transmitter except the centre external antenna. I'm wondering if the problems were caused by it covering the two internal antennas. If this is the case then I will have to look for some good flying gloves. Its disappointing because I really liked the glove and it did a good job of keeping my hands free and warm once it was on. It is a bit of a pain putting it on.

Chris

 

[Mark The Droner]

That's a good guess but I don't think the glove would block the internal patch antennas unless the glove had some sort of metallic substance in them. Also, the control signal comes from the stick antenna which is sticking out of the glove and upright (right?)...

 

[Chrislaf]

That's a good guess but I don't think the glove would block the internal patch antennas unless the glove had some sort of metallic substance in them. Also, the control signal comes from the stick antenna which is sticking out of the glove and upright (right?)...

Yes, the stick antenna was in the upright position. I don't think there is any metallic substance in the transmitter glove and I didn't think it would affect the AC control either since the internal antennas are already covered by the plastic of the transmitter case.

The only other thing I can think of is it was some sort of firmware issue. I updated the AC firmware after the problem flights. The flight apps, GO and Litchi were updated so I thought maybe there was some sort of mismatch between the AC firmware and the flight apps. When I flew yesterday from one of the exact same locations I had signal/control problems, everything worked great - no issues whatsoever. So either the transmitter glove caused problems or it was a firmware issue. Right now everything is working so that's great.

Chris