Litchi waypoint missions never complete - they simply stop mid way

Joined
Sep 22, 2015
Messages
35
Reaction score
3
Age
79
I have a Phantom 3 Pro and have been trying to work with the Litchi app to fly waypoint based missions.

My first attempt worked, but since then, pretty much none of my missions complete. They upload, they begin, and then spontaneously stop at some point during the execution. There are no warnings, no explanations... nothing on the display.

I've confirmed that I have PLENTY of battery, and there have been as many as 11 GPS satellites connected at the time it quits.

When it's happened, I have line of site to the drone, and it is well within range. At the time it gives up, I still have excellent video signal and can easily switch it back to "P" mode to fly it back to me.

How do I proceed?
What is the best way for me to get these missions to complete reliably?
For anybody that's interested... Mission Hub - Litchi

Thanks
 
What is the best way for me to get these missions to complete reliably?


Not completely certain as to the "stopping" issue, however of note, there are 3 small errors in your mission plan that I noticed at quick glance.

1) All of your waypoints are set for above ground, except Waypoint #1.

2) You have "actions" set in you mission but have your settings for "curved turns". Actions are ignored with this setting.

3) You have your finish action set to "Return to 1". It is right on top of Waypoint 1 basically. I would change that to "None".
 
  • Like
Reactions: Greybush
What is the best way for me to get these missions to complete reliably?
Not completely certain as to the "stopping" issue, however of note, there are 3 small errors in your mission plan that I noticed at quick glance.
1) All of your waypoints are set for above ground, except Waypoint #1.
2) You have "actions" set in you mission but have your settings for "curved turns". Actions are ignored with this setting.
3) You have your finish action set to "Return to 1". It is right on top of Waypoint 1 basically. I would change that to "None".

Good input. Thanks. I'll implement your suggested changes, re-save as a different mission, and give it a try. I think the only place I have actions is on the first and final points, but I'll double check to be sure.

It's still an open mystery though as to why my mission self-aborts mid way. One one attempt, it pooped out near either waypoints 7 or 8. On another, it stalled at about point 26.
 
So, I...
  • ... made the changes you suggested
  • ... double checked that there was no "max distance" hanging around from prior runs of the DJI Go app
  • ... cranked up the radius of the "red circle" so everything fell inside it
  • ... and even slowed down the cruising speed of the mission
Problem still there. :confused:

My goodness, this is frustrating.

How would I go about accessing any on-craft flight logs?
 
How would I go about accessing any on-craft flight logs?
Lets take a look at your device logs first, then if needed we can check the aircraft .dat file.
You can upload your device .csv file at this link, then share a link back here to that. Additional instructions are on the link:

Log Viewer

If this does not provide an answer, you will need the aircraft .dat file, which we can do after this attempt.
 
  • Like
Reactions: Oso
I up-loaded the flight log for yesterday morning's two attempts.
You only linked to one flight, however at initial look you may have a GPS issue of some sort. The aircraft switched to ATTI several times, then back to P-GPS then To NAVI. Your satellite counts were all over the place. Nothing really consistant. I suspect that the NAV HEALTH dropped to below 3 at those intervals. There is not enough data here to provide anything certain. Below you will see the Sat Counts vs the Fly State. If you wish to pursue the aircraft file, see the link below for instructions. Of note, there is another thread with a similar issue, as of now un-resolved.

How to Retrive P3 Dat

At times getting the correct .dat is difficult. But when you find the correct file you will need to upload that to a sharable link such as Drop Box, Google Drive, etc.... and share a link back here to the file.



112261
 
Hmmm...

That's an interesting thought about the GPS being fritzy, and is something I'll start watching for. After receiving your note above, I gave the flight another try, mainly to get a clean data record. The mission completed just fine... DJI Flight Log Viewer - PhantomHelp.com

How should I proceed at this point? If this were your drone, what would you be doing? More attempts and data logging?

Again, thank you for your help.
 
How should I proceed at this point? If this were your drone, what would you be doing? More attempts and data logging?

As I mentioned in post #7, the aircraft .dat will give a better idea as to what is happening. I would look at that from the previous flight. The Sat counts are still basically the same in the new flight as the previous one. I can check the timing of the dropouts from this file to see how they co-inside with good flight, but it is rather tedious.
 
As I mentioned in post #7, the aircraft .dat will give a better idea as to what is happening. I would look at that from the previous flight. The Sat counts are still basically the same in the new flight as the previous one. I can check the timing of the dropouts from this file to see how they co-inside with good flight, but it is rather tedious.

Hi Fly Dawg, I am having a similar problem in a different thread. Take a look here and see if you can figure out what happened. Anyway this link might tie the results of these two threads together:

Thanks Joe
KC7GHT
 
So, I...
  • ... made the changes you suggested
  • ... double checked that there was no "max distance" hanging around from prior runs of the DJI Go app
  • ... cranked up the radius of the "red circle" so everything fell inside it
  • ... and even slowed down the cruising speed of the mission
Problem still there. :confused:

My goodness, this is frustrating.

How would I go about accessing any on-craft flight logs?
The max distance just gives you a warning and does not restrict the flight. I set mine at zero to do away with the red circle.
 
As I mentioned in post #7, the aircraft .dat will give a better idea as to what is happening. I would look at that from the previous flight. The Sat counts are still basically the same in the new flight as the previous one. I can check the timing of the dropouts from this file to see how they co-inside with good flight, but it is rather tedious.

I took a little investigtion, but I think I found it...


I hope this provides some clues.
 
@BlueVista ...That appears to be the correct flight. There is undoubtedly an issue with the GPS of some sort. The dropouts are correlate with the Nav Health dropping below 3. Let me see if I can get a more detailed answer for you when @sar104 or @BudWalker have the chance to take a look. Below is just one of the dropouts. There were 3 if I counted correctly.

112311
 
Well, I think this is both good news and bad news.

On the good side, it seems like the mystery is now largely understood to be GPS related.

The bad news is that if proven out to be true, I'm not sure what my next step is. This thing's way past warranty. Would this be something that could be fixed in a reasonable timeframe and at reasonable cost?

Interestingly, since my problems on Saturday and the days leading up to it, I couldn't get a single mission to complete. From then until now, however, it's been completing missions just fine.
 
For comparison purposes, the first graph below is the sat counts from the flight with the dropouts. The second graph is from your good flight. Both from the device file, but note the similarity.

DROPOUT FLIGHT

112314



GOOD FLIGHT

112315
 
@BlueVista ...That appears to be the correct flight. There is undoubtedly an issue with the GPS of some sort. The dropouts are correlate with the Nav Health dropping below 3. Let me see if I can get a more detailed answer for you when @sar104 or @BudWalker have the chance to take a look. Below is just one of the dropouts. There were 3 if I counted correctly.

View attachment 112311
Looks to me like the sat count is marginal and there are occasional problems. An increase in the hDOP causes the navHealth to drop.
112317
 
From then until now, however, it's been completing missions just fine.
As @BudWalker mentioned your Sat Counts are marginal at best, as I noted previously. Just to eliminate a variable and see the results. Try flying a quick manual flight in a different area than the above. As a test, simply fly up to around say 150ft or so and hover there. Watch your device Sat counts while you hover for a few minutes.Then after that flight, upload the device file from that flight. Personally, I would be willing to say at this point that the results will be similar. However, that is what testing is for.
 
And now, of course, it's supposed to rain around here for a couple of days. :-(

Even so, the graphs certainly support the theory that this is GPS related. I'll give your test a try at my first opportunity and will report back here.

So supposing this is an indication that my GPS is starting to go south, what are my options?

@Fly Dawg and @BudWalker ... thanks for the help. Greatly appreciated.
 
So between work and weather, I was able to make a couple more attempts. One succeeded, one failed.

The one that succeeded was a little more involved, and actually had part of the failed mission's flight plan in it.

The one that failed was a repeat of the mission that started me down this path...

The links above show the Litchi mission and the flight logs. I was also able to get the related DAT files and even the video recordings made during the missions and have them all uploaded to Google Drive.
For the one that failed, at the time of the first failure, I looked at the Android/Litchi display, and it showed that I had plenty of satellites. I then attempted to re-start the mission 2-4 times before just giving up and taking over control to burn down the battery a bit and to log some extra flight data.

So what am I up against with all of this?
 
I looked at FLY102.DAT - Bad one... 19-06-27 . It shows the same problem described in post #16. The satellite count was marginal and occasionally the horizontal Dilution of Precision (red) would increase. This then causes the FC to become less confident in the location that it is always computing. That confidence level is shown in the navHealth signal (blue). When the navHealth dips below 3 the FC will then switch to ATTI mode because it can't use GPS to compute location. I suspect that the mission is aborted when this happens.
112394
 

Members online

No members online now.

Forum statistics

Threads
143,066
Messages
1,467,358
Members
104,936
Latest member
hirehackers