RTH triggered in Litchi waypoint mission

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I'm very puzzled by what happened this afternoon.

Last night I planned a 12 minute waypoint mission (short enough to give a generous margin for battery life). Cruising speed (26mph) was selected for every waypoint. The route included quite high hills, so the waypoints changed from 250ft altitude to 950ft partway through the route.

Everything went well at first, then I lost signal (which didn't worry me too much since that's often happened). But the signal was lost for a worryingly long time, and when I looked at the data, it said the craft's speed was only 8mph. I know it might have been climbing steeply at that point, but that reduction in speed still seemed odd. And then suddenly 'returning home' came up on the screen. I just couldn't figure out why this should happen - I launched with a full battery and battery was at about 60% when I lost signal, and in any case, doesn't Litchi just land the craft wherever it happens to be if the battery runs too low on a waypoint mission?

The route on the map confirmed that RTH was in progress, as it was taking a much more direct route back than the waypoints would have taken it. Then another odd thing happened - the video stopped recording. I switched it on again but a few seconds later I heard 'recording stopped' again. Then every time I started the recording, it stopped again.

I landed the craft - a P2A, by the way - then looked at the waypoint mission. As I expected, at every waypoint the cruising speed of 26mph was selected, and all the altitudes were as I'd selected. The area I was flying in wasn't a no-fly zone so that couldn't have triggered RTH. I'm totally mystified.
 
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First, any info you have on the screen while you are "lost connection" won't be correct - no data coming in. You didn't say how far into the mission the bird got while lost link. Could it have completed the mission and returned home like it was supposed to? And finally, how full was your SD card? Just deleting files often doesn't free up space on the card. You should make it a point to format the card in the app before you start any mission.
 

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There's no such thing as a P2A.

The speed is horizontal. So if you are in a steep climb, it can be impossible to move horizontally at a given speed.

Often when I get disconnected and then reconnected, my app will tell me "recording stopped" followed by "recording started" when in fact the recording never stopped.
 
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I'm very puzzled by what happened this afternoon.

Last night I planned a 12 minute waypoint mission (short enough to give a generous margin for battery life). Cruising speed (26mph) was selected for every waypoint. The route included quite high hills, so the waypoints changed from 250ft altitude to 950ft partway through the route.

Everything went well at first, then I lost signal (which didn't worry me too much since that's often happened). But the signal was lost for a worryingly long time, and when I looked at the data, it said the craft's speed was only 8mph. I know it might have been climbing steeply at that point, but that reduction in speed still seemed odd. And then suddenly 'returning home' came up on the screen. I just couldn't figure out why this should happen - I launched with a full battery and battery was at about 60% when I lost signal, and in any case, doesn't Litchi just land the craft wherever it happens to be if the battery runs too low on a waypoint mission?

The route on the map confirmed that RTH was in progress, as it was taking a much more direct route back than the waypoints would have taken it. Then another odd thing happened - the video stopped recording. I switched it on again but a few seconds later I heard 'recording stopped' again. Then every time I started the recording, it stopped again.

I landed the craft - a P2A, by the way - then looked at the waypoint mission. As I expected, at every waypoint the cruising speed of 26mph was selected, and all the altitudes were as I'd selected. The area I was flying in wasn't a no-fly zone so that couldn't have triggered RTH. I'm totally mystified.
I had a similar experience a couple days ago, programmed a decent legnth waypoint trip all was going as programmed at cruising speed it got to the poi's I had set (my buddies house) it dropped down to set altitude and did the paning I programmed at the speed I programmed (6 mph) it then climbed to next wp and was supposed to speed up to cruising speed and it just continued at the 6mph I've double triple checked the wp's speeds are correctly programmed. The thing that is similar to you is dropping down near my buddies house made me lose signal for 45 secs to a minute ( I didn't worry as I trusted the programmed flight ) and when I regained signal it was still cruising back at 6mph not at cruising speed as it should have after last wp near his house and that's why there was signal lost so long lol also ran into it stopping recording when it wasn't programmed to. I ran the mission again with all actions at wp's turned off and just started recording manually at beginning it recorded whole mission and all wp turns, heights etc look correct just that after losing contact for awhile it doesn't increase speed to cruising speed when it's supposed to it finishes all the wp's after signal loss at the speed it was doing when signal was lost. I figured I was doing something wrong and that may be but looks like 2 ppl with same issue we may be onto something faulty here in litchi lol mine never triggered rth as by the time signal was regained I was still at 70% but speed definitly never increased to cruise speed on any wp's after signal loss it stayed at speed it was during signal loss and all wp's after that part of mission are set at cruise speed. Side note all other actions seemed to work after signal loss/regain I.e. craft rotating how I programmed heights I programmed (thank God heights went to where programmed lol) just speed seems affected after the signal loss.
 
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Sorry, just to correct a typo - my bird is a P3A.

I don't think it had completed its mission - 'returning 'none' came up against a pale blue background which is something I have never seen before on Litchi and it definitely did not take the planned return route but cut across.

As for the 8mph indication - could it have meant horizonal speed? If it was climbing steeply that might be the explanation.

As for recording stopping, my sd card was empty when I started and is 16gb, video cache recently cleared and auto caching disabled.
 
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Sorry, just to correct a typo - my bird is a P3A.

I don't think it had completed its mission - 'returning 'none' came up against a pale blue background which is something I have never seen before on Litchi and it definitely did not take the planned return route but cut across.

As for the 8mph indication - could it have meant horizonal speed? If it was climbing steeply that might be the explanation.

As for recording stopping, my sd card was empty when I started and is 16gb, video cache recently cleared and auto caching disabled.
Just out of curiosity what brand name phone or tablet were you using? I have been pretty critical of Litchi from day one, based on the onslaught of mysteries with 'Litchi' in the title. I suspect many of these are with Samsung phones and tablets, but I have not compiled any data yet. NOTE: There is a Litchi cult on these forums who swear that Litchi is The. Best. App. and have never ever not even maybe had a problem in a quadrillion flights. And I believe many users have flown with Litchi with no problems, but even one lost bird is pretty important to the one who lost their bird. And every lost aircraft is chaulked up to operator error. I have bought Litchi and have installed it onto a few different devices, but have not flown it yet. If I ever do I will for sure not fly it initially with a full battery. I do not want to put enough gas in the tank for it to get clean away.
 
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Sorry, just to correct a typo - my bird is a P3A.

I don't think it had completed its mission - 'returning 'none' came up against a pale blue background which is something I have never seen before on Litchi and it definitely did not take the planned return route but cut across.

As for the 8mph indication - could it have meant horizonal speed? If it was climbing steeply that might be the explanation.

As for recording stopping, my sd card was empty when I started and is 16gb, video cache recently cleared and auto caching disabled.
It would be helpful if you could share your flight log (upload to healthydrones.com and post link in this thread) and share the mission in the litchi hub. Good chance you will get an explanation and/or we will learn some peculiarity of litchi that we need to be mindful of.
 
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I think the "speed" settings are only good as long as you have a signal, if you lose communication the aircraft maintains the last speed it was flying
 
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I think the "speed" settings are only good as long as you have a signal, if you lose communication the aircraft maintains the last speed it was flying
I wish DJI would publish a technical paper or whatever they would like to call it, even a software flowchart, describing exactly how autonomous flight behaves.

We sort of, kinda, maybe, think we know how it works in most circumstances, almost. I just see so many questions about if signal is lost, if mode goes from 'F' to 'P', if signal is not lost but RTH is engaged, if signal is lost and then RTH....etc. etc. I have been flying around this big soccer complex trying all these different combinations in the hope of never having an Oh **** moment where my bird goes AWOL. It would be helpful to know all this some way other than trial and error, or trial and New Bird.
 
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I wish DJI would publish a technical paper or whatever they would like to call it, even a software flowchart, describing exactly how autonomous flight behaves.

We sort of, kinda, maybe, think we know how it works in most circumstances, almost. I just see so many questions about if signal is lost, if mode goes from 'F' to 'P', if signal is not lost but RTH is engaged, if signal is lost and then RTH....etc. etc. I have been flying around this big soccer complex trying all these different combinations in the hope of never having an Oh **** moment where my bird goes AWOL. It would be helpful to know all this some way other than trial and error, or trial and New Bird.
Everything that may be obtained through the SDK implementation is fully published by DJI (including autonomous flight).

I suspect you are unnecessarily concerned with the prospect of a fly away. We know, from various threads and discussions in this and other forums, that there are known Litchi and other App issues that we need to be mindful of. Examples include failure of RTH to initialize on P3 standard and 4k with lost signal in specific circumstances, current NFZ reporting errors causing unexpected auto land/stop and hover etc.

Most issues relate more to the operator doing, or probably equally as often, failing to do something that either contributed to or may have avoided the outcome. We also frequently see circumstances where new operators avail themselves of the advanced features in litchi (and other Apps) ending with a scenario where they lack the ability to manually fly the AC to safety. A simple logical approach might be to not engage any mission that couldn't be comfortably flown manually.
 
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I'm very puzzled by what happened this afternoon.

Last night I planned a 12 minute waypoint mission (short enough to give a generous margin for battery life). Cruising speed (26mph) was selected for every waypoint. The route included quite high hills, so the waypoints changed from 250ft altitude to 950ft partway through the route.

Everything went well at first, then I lost signal (which didn't worry me too much since that's often happened). But the signal was lost for a worryingly long time, and when I looked at the data, it said the craft's speed was only 8mph. I know it might have been climbing steeply at that point, but that reduction in speed still seemed odd. And then suddenly 'returning home' came up on the screen. I just couldn't figure out why this should happen - I launched with a full battery and battery was at about 60% when I lost signal, and in any case, doesn't Litchi just land the craft wherever it happens to be if the battery runs too low on a waypoint mission?

The route on the map confirmed that RTH was in progress, as it was taking a much more direct route back than the waypoints would have taken it. Then another odd thing happened - the video stopped recording. I switched it on again but a few seconds later I heard 'recording stopped' again. Then every time I started the recording, it stopped again.

I landed the craft - a P2A, by the way - then looked at the waypoint mission. As I expected, at every waypoint the cruising speed of 26mph was selected, and all the altitudes were as I'd selected. The area I was flying in wasn't a no-fly zone so that couldn't have triggered RTH. I'm totally mystified.

I was flying a waypoint litchi mission and my p3a RTH'd, I did not know why either. It will be interesting to see how this thread evolves, hopefully someone knows what is going on.
 
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I had a similar experience a couple days ago, programmed a decent legnth waypoint trip all was going as programmed at cruising speed it got to the poi's I had set (my buddies house) it dropped down to set altitude and did the paning I programmed at the speed I programmed (6 mph) it then climbed to next wp and was supposed to speed up to cruising speed and it just continued at the 6mph I've double triple checked the wp's speeds are correctly programmed. The thing that is similar to you is dropping down near my buddies house made me lose signal for 45 secs to a minute ( I didn't worry as I trusted the programmed flight ) and when I regained signal it was still cruising back at 6mph not at cruising speed as it should have after last wp near his house and that's why there was signal lost so long lol also ran into it stopping recording when it wasn't programmed to. I ran the mission again with all actions at wp's turned off and just started recording manually at beginning it recorded whole mission and all wp turns, heights etc look correct just that after losing contact for awhile it doesn't increase speed to cruising speed when it's supposed to it finishes all the wp's after signal loss at the speed it was doing when signal was lost. I figured I was doing something wrong and that may be but looks like 2 ppl with same issue we may be onto something faulty here in litchi lol mine never triggered rth as by the time signal was regained I was still at 70% but speed definitly never increased to cruise speed on any wp's after signal loss it stayed at speed it was during signal loss and all wp's after that part of mission are set at cruise speed. Side note all other actions seemed to work after signal loss/regain I.e. craft rotating how I programmed heights I programmed (thank God heights went to where programmed lol) just speed seems affected after the signal loss.
Note, the manual specifically states that if signal is lost during a mission, the mission will continue at the speed it was flying when the signal was lost.
 
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I wish DJI would publish a technical paper or whatever they would like to call it, even a software flowchart, describing exactly how autonomous flight behaves.

We sort of, kinda, maybe, think we know how it works in most circumstances, almost. I just see so many questions about if signal is lost, if mode goes from 'F' to 'P', if signal is not lost but RTH is engaged, if signal is lost and then RTH....etc. etc. I have been flying around this big soccer complex trying all these different combinations in the hope of never having an Oh **** moment where my bird goes AWOL. It would be helpful to know all this some way other than trial and error, or trial and New Bird.
Have you downloaded and read the latest version of the litchi manual? Many of the questions and issues that are posted are covered in the manual.
 
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Note, the manual specifically states that if signal is lost during a mission, the mission will continue at the speed it was flying when the signal was lost.
I understand that also in app upon launching a saved mission the pop-up that comes up says if signal is lost the mission will continue at speed at which signal was lost (not verbatim lol) I've had missions lose signal and when it's regained it's going the speed at which it was going when lost as expected it would happen , I didn't make myself clear that's my bad lol, when good signal is regained and it is going through the remainder or the wp's it uses the speeds I set for those wp's I've even flown that same mission and it cuts out in same place and when regained and finishing up the wp's it does the speeds I set but this particular instance it continued at the slow speed I had set when it lost signal but even after regaining signal it never sped up to the remainder of the wp's speeds, it stayed at that speed throughout the last part of mission even after solid signal regained. So it's unclear which is the fluke it finishing the mission at the slow speed when signal was lost even after regaining good signal or when I did mission again when it sped up to programmed speeds after signal regain. It can't be both so one of the times litchi misbehaved lol
 
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Even more interesting is that you lost signal in the same location on multiple missions. Sounds like there is something blocking, possibly interfering with your link signal. That might be more of a factor than any hiccups in litchi.
 
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Even more interesting is that you lost signal in the same location on multiple missions. Sounds like there is something blocking, possibly interfering with your link signal. That might be more of a factor than any hiccups in litchi.
Oh it's definitely blockage lol I knew it probably would in that part of mission when I was making it. That part goes about 1600 feet which isn't too far but then dips low over a green Chile field and and runs slowly along the field parallel to the road with my buddies house as poi (made the mission when I was showing him how litchi and quads work he's never seen one lol) well between my place and his is houses and a lot of trees with everything else around open alfalfa and Chile fields lol I knew it would block signal but have confidence in litchi to fly the mission and it did. My confusion comes from after signal regain is litchi supposed to finish the remainder of wp's at speed I set at them at or do the rest at speed from when signal was lost unless I interfere and speed it up? It did both scenarios so I'm not sure which is correct and it would be good knowledge to have for future missions where I think a good chance of signal loss in a mission I'm planning . Thanks and happy flying
 
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After reading this thread, I too have had it where it came back RTH during a mission. At first, I thought my wife may have pressed the RTH button. On the second, my RC began beeping due to RC inactivity so I closed Litchi, and the beeping ended after reopening the app. On another mission, it did the same, but upon reopening Litchi, I started getting the RTH beeping.

That second mission with RTH activated was an easy but long flight. When I watched the video, it got to about 1/4 mile less than the farthest distance out before it turned around RTH. When the weather clears, I will attempt the same mission to see if I can recreate the problem, but I will not close Litchi.

Just asking, other than receiving video and telemetry(and my occasional controlling the gimbal), does Litchi send any control to the bird during a WP mission? I thought each WP mission was completely autonomous so no inflight control during the flight should be happening.
 
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Actually, Litchi has to remain in contact with the bird before the mission will respond to any sped changes or POI angles, etc. It's slightly misleading to state that Litchi will 'continue a mission' when lost link. It will, but it may be a modified or limited version of the mission.
 
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After reading this thread, I too have had it where it came back RTH during a mission. At first, I thought my wife may have pressed the RTH button. On the second, my RC began beeping due to RC inactivity so I closed Litchi, and the beeping ended after reopening the app. On another mission, it did the same, but upon reopening Litchi, I started getting the RTH beeping.

That second mission with RTH activated was an easy but long flight. When I watched the video, it got to about 1/4 mile less than the farthest distance out before it turned around RTH. When the weather clears, I will attempt the same mission to see if I can recreate the problem, but I will not close Litchi.

Just asking, other than receiving video and telemetry(and my occasional controlling the gimbal), does Litchi send any control to the bird during a WP mission? I thought each WP mission was completely autonomous so no inflight control during the flight should be happening.
Is it possible that the "smart Go Home" setting (applied in the DJI GO app) is causing RTH to be triggered. We know the setting is stored in the AC.
 
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Since you mentioned the Go app, that brings up another issue. You have to make absolutely sure that Go is not running in the background.there have been numerous posts here about problems being traced back to both running and causing conflicts. And, apparently, Go can restart itself in the background on android devices which can cause those issues to creep up on you.
 
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