Warning for litchi users

[Pharm]

I never changed any settings in mine.

I didn't do it on purpose. I think my big thumb did it.

 

[eliomartin]

Good afternoon friends, just to inform you, Litchi switches from PGPS to ATTI when the number of satellites drastically reduces, and there is usually the possibility of a fly away, this is a more secure system than any other. You should take the atitide to put your key into atti, steer a few seconds for the drone to reschedule atti and then you can try again putting the key into PGPS. Almost always it reprogramme in pgps, however in several cases it assumes a new home point, then at that moment you must return immediately. I advise to be done IMU calibration, then turn everything off and then do the calibration of the compass. This is a Bug and all the drones that arrived broken in the DJI because of this they have given the guarantee. As for existing flight data using Litchi, it does exist. There is an additional chip inside the drone that records everything even if another app is used, a black box, and every time you turn on the DJIGo it retrieves that data. So it is not advisable to use pirated app.

 

[Eddie Pitwell]

I have had a very similer issue to this. However i then tried the other app DJI ultimate and on the waypoint missions it did a very similar thing and when i tried to rth it turned and flew off. I had to uninstall app and use rth on the controller to get it back.

So went home and started to hunt for the issue..... found in dji go app (that i made sure before flying was not open when using both litchi and ultimate) that for some reaon in the settings had changed, certainly not by me, on the gps to mainland china.

Have switched settings back but havent tested due to work/weather but should be able to do tomorrow. Will report back after testing both litchi and ultimate.

 

[eliomartin]

These changes are rarely happening, but they happen inside the drone, the app has nothing to do with it. The app is only a panel that shows the SDK information, and only changes with the pilot's consent. That of the drone flying out in another direction or during a flight or when pressing RTH is due to the deprogramming inside it. Ai have to hit the key atti wait a few seconds, or go back to atti or try to reprogram the drone putting it back on pgps after a few seconds .... but do not rely fully on the homepoint.

 

[sweez]

So I was flying a litchi waypoint mission today and litchi glitched out. Quad was on it's way to the first wp when suddenly litchi switched from navi mode to atti then quickly to GPS mode. The bird just sat there hovering but on-screen the status said it was still moving to next wp but speed was 0mph as it was just hovering in GPS mode. I hit the play icon again to see if it would continue mission but it headed back to first wp to start mission again so I just stopped it at that point. My warning is if this was to happen while signal was lost at a far wp then the bird will just be hovering there draining battery while you think it's continuing along with the mission as advertised. By the time you figure out it's been gone too long and not returning too much battery may be lost and you may lose your bird before you can fix the situation and bring bird back yourself. Just want to give all you litchi users a heads up to watch for this glitch I'd hate to hear of one of y'all losing your bird due to this problem with litchi. I've never had this happen before litchi is usually rock solid app but it makes me wonder now lol happy flying

Sent from my SM-S320VL using PhantomPilots mobile app

Had a instant similar but different
I have ran many Wp Mission and got disconnected message,
but it completes the mission.
Then running a short WP mission 900 feet or so out and back.
at about 800 out Had 17 Sat , 88 % controller 83 Precent Battery. Video dropped Low
Only thing that was lower than normal
was Controller power at 21 %.

Then got message "DISCONNECTED" IN RED , strong Rc, weak Video , speed droped from 10
to 2 mph.
Then message "Landing Tap to Cancel" Tryed several time said execution time out 1003,
tryed several time to cancel landing, 3 times, then hit no instead of yes to cancel
by mistake. almost landed.

i just push left stick up got altitude back, it continued on route. Like continuing mission..

Dazzed, conused, I hit return home, It, came home , have NOT tryed another since. worried

 

[Mike's Bird]

Since this seems to be the place for Litchi glitches, here's my story...

I haven't flown in a while but I have hundreds of miles and many, many successful Litchi way-point missions under my belt. Never had any issues with the way-point feature. Fire and forget, as they say. That particular feature is actually the primary reason I use Litchi. Anyway, with a charged battery, phone and controller I did my pre-flight routine with the bird and set out for a flight in over some farm land. I've flown this area many times and have confidence (with my DBS modded controller) RF interference is nil.

About 7500 feet out I had full strength for RC and FPV indicated on (Android) app. Then it happened. The red block with "disconnected" appeared on the app. For the first couple of seconds I thought, "No big deal, I'll simply adjust my aim a bit and everything will be back to normal". Not so fast. I took a screen shot of the last FPV image and began to wonder if there was something more going on. Hitting a bird was my first thought. The next several minutes consisted of doing everything from re-starting the app to flipping the RTH switch on the controller, to sacrificing a chicken to the god of quads. But alas, no chicken to be found. Panic? Oh yea! I've read the countless stories of fly-a-ways and lost Phantoms happening to others, but that could ever happen to me. I finally looked at the app settings and, disconnected from the bird at this point, it shows the bird will hover upon disconnect.... a setting I was willing to swear I set as RTH.

So, with about 30 - 40 of usable light left in the day (great light for photography, not for losing drones) I set out for a jog. I covered about a mile in long grass and realized the hunt would have to wait until tomorrow. No more usable light in these conditions and even with the RC / android device with me, I could never re-connect. My watch also said there was no way it could still be in the air, "hovering".

I trudged back convinced the probability of recovery was less than 50% and after a heavy dew that night, it would be most likely toast. I began to rationalize 'Heck, it was just a Standard so... upgrade time?'

In my final approach to the launch area, I saw what can only be considered a Christmas miracle. The bird sat there, upright in 12" grass, flashing yellow, less than 3 feet from it's initial take off area. No damage. It did RTH, although I'm not quite sure if that was my manual switch or what. I did have a bit of a laugh at myself when reviewing the SD card .... Yes, that was me clear as day, running from the initial launch point in hopes of finding it. I should have waited about 90 seconds more before leaving. I haven't flown since but I did check the settings on Litchi. Now I see the RTH setting is indeed just as I set it, but only when connected to the controller and bird. I have never used Healthy Drones or reviewed any raw data before but maybe I should start. This was the first real Oh - S incident I've had in a year of flying. My concern is the sudden loss of connection with a signal strength at full bars. I haven't done updates to the bird (using DJI Go app) since 3.7. I have a 'if it's not broke, don't fix it' approach. Wrong? The Litchi app is up to date.

 

[GeoffJ]

Make sure you report this to Litchi, with any evidence you have.
If there's a glitchi in Litchi, they'll fix it.

 

[Schnoidz]

I've only done about 40 waypoint missions so far but haven't had a single problem yet, other than the "failed to load" message which then loaded on the second try.

Just thought I'd post a "works for me, no problems" message since people usually only post when there's a problem or question. I've been using the android version on a Nexus 6P but just got the Nvidia Shield K1 yesterday and will be using that now. This is on the P3P.

Litchi hasn't crashed on me yet but DJI GO has twice. I (almost) always reboot my android before the first flight so I get a fresh start.

 

[pe9999]

How can you use dji go and litchi at the same time?

 

[Wessex]

This problem of switching (not from the RC unit but within the A/C) to ATTI mode and back again would appear, if I've understood the posts correctly, to cancel the mission program. If this is the case then why cannot the developers alter the programming to instigate the RTH feature unless this switching to ATTI mode cancels the home point setting.

Now I've read the whole 89 posts and the question arising seems to be why does the A/C switch to ATTI mode when the display is reading 12+ satellites? Well the A/C can see these satellites but the signal strength from these satellites will vary in their signal-to-noise ratio. In other words, yes it sees all these satellites but how many are actually of any use in providing a fix at any given time?

Next is the Kp index. In the app UAV Forecast it gives the Kp forecast updated every three hours.

(Quoted from the Help section in UAV Forecast)

Q. What is the Kp index, and why does it matter?
The Kp index measures geomagnetic disruption caused by solar activity, on a scale from 0 (calm) to 9 (major storm). Anything at or below 3 or 4 is usually safe for flying. The higher the Kp index, the more likely you are to have diffulties getting an accurate GPS lock.

Solar activity interferes with GPS signals in two ways, both due to disruptions in the ionosphere:

• It decreases the signal-to-noise ratio and affects carrier frequency, causing the receiver to lose lock on some satellites. Instead of 9 satellites, you might lock only 6, or the number might fluctuate from second to second.
• It changes the propagation delay through the ionosphere, making GPS positioning inaccurate even if the receiver has all satellites locked.

Even during a major storm, the extent to which you see these problems will depend on many other factors. One major factor is your latitude: ionospheric disturbances are worse at high and equatorial latitudes, and less noticeable at mid latitudes. Another factor is the time of day: most disturbances occur in the evening between the hours of 8pm and midnight. The effects also vary; sometimes everything will be fine, while at other times you'll lose lock completely for a few seconds or even a minute, or appear to have a lock but the position will actually be wrong by hundreds of feet.

The storms can also interfere with radio control signals, or with electronics of your aircraft.

In general it's better to play it safe during solar storms, even though most of the time you won't notice any issues. Happy flying!

For a nice research paper demonstrating the effect of solar activity on GPS, read Impacts of ionospheric scintillations on GPS receivers intended for equatorial aviation applications by Groves et. al.

So, I think this is an important factor to be considered as to why the control of the A/C suddenly goes into ATTI mode: even if it's only briefly, it can cause major problems.

 

[WilliamM]

How can you use dji go and litchi at the same time?

NO. And at least on Android there's even a little warning pop up that informs you that the go app cannot even be loaded into memory.

Sent from my HTC 10 using PhantomPilots mobile app

 

[Dixie Flyer]

I'm with QuadcopterCrazy on this one... I had a similar experience with Litchi and have been warning people ever since. (Several rants on multiple forums) Litchi has great potential but with several potentially dangerous downsides. I'll address just this one:

When switching from screen to screen or enlarging the screen you must "touch the screen". Whenever you touch the screen you risk accidentally inserting another waypoint. If the newly inserted waypoint is near a previous waypoint you may not even see it on the screen and may not realize you did it. This bit of wisdom comes to you via bad experience.....

It really becomes an issue if the new waypoint is at a lower altitude and your bird is headed for the new lower altitude with obstacles in the way. Litchi ignores/disables the obstacle avoidance features of the P4. Litchi customer service tends to jump directly into survival mode and will blame the operator before asking for any facts. (I have the online chat transcript) Also if using a 3rd party app you negate any warranty claims with DJI. Can't expect DJI to honor their warranty if using someone else's software.

PS: Cannot run DJI Go and Litchi simultaneously. Bad JuJu.

 

[WilliamM]

I'm with QuadcopterCrazy on this one... I had a similar experience with Litchi and have been warning people ever since. (Several rants on multiple forums) Litchi has great potential but with several potentially dangerous downsides. I'll address just this one:

When switching from screen to screen or enlarging the screen you must "touch the screen". Whenever you touch the screen you risk accidentally inserting another waypoint. If the newly inserted waypoint is near a previous waypoint you may not even see it on the screen and may not realize you did it. This bit of wisdom comes to you via bad experience.....

It really becomes an issue if the new waypoint is at a lower altitude and your bird is headed for the new lower altitude with obstacles in the way. Litchi ignores/disables the obstacle avoidance features of the P4. Litchi customer service tends to jump directly into survival mode and will blame the operator before asking for any facts. (I have the online chat transcript) Also if using a 3rd party app you negate any warranty claims with DJI. Can't expect DJI to honor their warranty if using someone else's software.

PS: Cannot run DJI Go and Litchi simultaneously. Bad JuJu.

Disagree regarding the warranty claim not being honored using third-party apps. Have read multiple posts by DJI reps on their forum stating that is not the case. They may not accept third-party logs for flight data, but they do not just reject a warranty claim because you used other software. But obviously if the crash was caused by the third party software and not caused by their hardware they would not honor the claim because they are not at fault.

Sent from my HTC 10 using PhantomPilots mobile app

 

[Mike's Bird]

I've only done about 40 waypoint missions so far but haven't had a single problem yet, other than the "failed to load" message which then loaded on the second try.

Just thought I'd post a "works for me, no problems" message since people usually only post when there's a problem or question. I've been using the android version on a Nexus 6P but just got the Nvidia Shield K1 yesterday and will be using that now. This is on the P3P.

Litchi hasn't crashed on me yet but DJI GO has twice. I (almost) always reboot my android before the first flight so I get a fresh start.

Oh, don't get me wrong, I love what Lichi has done and the product they have. I've had great confidence in the app (running on a Galaxy S4) and hundreds of incident free way-point missions. Losing signal has occurred many times, especially in WiFi congested areas, but I've been able to anticipate the loss of signal by watching the signal strength indicators. The issue I described may way be a 'one-off' and of no concern. It did end well after all.

My post was a cautionary tale to pass on the lesson I learned - It CAN happen, to anyone.

 

[Jayfdee]

This problem of switching (not from the RC unit but within the A/C) to ATTI mode and back again would appear, if I've understood the posts correctly, to cancel the mission program. If this is the case then why cannot the developers alter the programming to instigate the RTH feature unless this switching to ATTI mode cancels the home point setting.

Now I've read the whole 89 posts and the question arising seems to be why does the A/C switch to ATTI mode when the display is reading 12+ satellites? Well the A/C can see these satellites but the signal strength from these satellites will vary in their signal-to-noise ratio. In other words, yes it sees all these satellites but how many are actually of any use in providing a fix at any given time?

Next is the Kp index. In the app UAV Forecast it gives the Kp forecast updated every three hours.

(Quoted from the Help section in UAV Forecast)

Q. What is the Kp index, and why does it matter?
The Kp index measures geomagnetic disruption caused by solar activity, on a scale from 0 (calm) to 9 (major storm). Anything at or below 3 or 4 is usually safe for flying. The higher the Kp index, the more likely you are to have diffulties getting an accurate GPS lock.

Solar activity interferes with GPS signals in two ways, both due to disruptions in the ionosphere:

• It decreases the signal-to-noise ratio and affects carrier frequency, causing the receiver to lose lock on some satellites. Instead of 9 satellites, you might lock only 6, or the number might fluctuate from second to second.
• It changes the propagation delay through the ionosphere, making GPS positioning inaccurate even if the receiver has all satellites locked.

Even during a major storm, the extent to which you see these problems will depend on many other factors. One major factor is your latitude: ionospheric disturbances are worse at high and equatorial latitudes, and less noticeable at mid latitudes. Another factor is the time of day: most disturbances occur in the evening between the hours of 8pm and midnight. The effects also vary; sometimes everything will be fine, while at other times you'll lose lock completely for a few seconds or even a minute, or appear to have a lock but the position will actually be wrong by hundreds of feet.

The storms can also interfere with radio control signals, or with electronics of your aircraft.

In general it's better to play it safe during solar storms, even though most of the time you won't notice any issues. Happy flying!

For a nice research paper demonstrating the effect of solar activity on GPS, read Impacts of ionospheric scintillations on GPS receivers intended for equatorial aviation applications by Groves et. al.

So, I think this is an important factor to be considered as to why the control of the A/C suddenly goes into ATTI mode: even if it's only briefly, it can cause major problems.

Thanks a well reasoned response, can anyone check the Kp at the time of the fault?
I never give it a second thought, even though I have an app that lights up in red if over 5. If the weather is good I fly.

 

[GFields]

Not sure why that would be the fault of any app, hitting a beam? If anything it sounds like a fault of the Phantoms avoidance system. And not even sure if that's the case because a beam is pretty slim, not sure if the avoidance system is that sensitive. Sounds more like a programming error setting up the flight plan.

Sent from my HTC 10 using PhantomPilots mobile app

"a beam is pretty slim,", Poor assumption, it was a 10-inch beam plenty large enough for the system to see/find if it is working. Also, I had read in other forums of others having issues with Litchi app and avoidance system. The avoidance system had worked earlier using the DJI GO app. So, what is one to conclude? Perhaps hitting a bird? I searched for blood and feathers LOL none to be found. It is unfortunate, but the video feed was damaged in the crash so I had no way to know for sure. DJI repaired at a cost, although denying anything wrong with the avoidance system. Nonetheless, the next WP mission using Litchi app will be a small one for testing purposes before trying anything like I had before.

 

[GeoffJ]

I once accidentally created an extra waypoint before loading a mission into the bird and this caused a close call with some power lines. I referred it to Litchi and they said were intending to include a "lock" which you would have to turn off before editing waypoints in the near future. Sounds like a good solution to this.
The bird flicking out of P mode, and thus turning off Litchi, is not really a Litchi problem. You need to be able to do that manually, and if the bird does it itself, I'd say that's more a DJI issue. You can't have Litchi throwing away the keys and locking itself in.

 

[GFields]

Disagree regarding the warranty claim not being honored using third-party apps. Have read multiple posts by DJI reps on their forum stating that is not the case. They may not accept third-party logs for flight data, but they do not just reject a warranty claim because you used other software. But obviously if the crash was caused by the third party software and not caused by their hardware they would not honor the claim because they are not at fault.

Sent from my HTC 10 using PhantomPilots mobile app

I know first hand they will not honor the warranty if crash/damage is caused by using a 3rd party app. They refused to cover mine damage because I was using the Litchi app.

 

[WilliamM]

I know first hand they will not honor the warranty if crash/damage is caused by using a 3rd party app. They refused to cover mine damage because I was using the Litchi app.

Yes that's what I said. "crash/damage is caused by using a 3rd party app" if 3rd party software causes damage why would they cover that? It wasn't their app that caused it. Your claim would be with Litchi in that case, not DJI. I'm making the distinction between hardware and software (the app). If it was truly a hardware issue that caused damage, you using Litchi won't void the warranty.

 

[Wessex]

I once accidentally created an extra waypoint before loading a mission into the bird and this caused a close call with some power lines. I referred it to Litchi and they said were intending to include a "lock" which you would have to turn off before editing waypoints in the near future. Sounds like a good solution to this.
The bird flicking out of P mode, and thus turning off Litchi, is not really a Litchi problem. You need to be able to do that manually, and if the bird does it itself, I'd say that's more a DJI issue. You can't have Litchi throwing away the keys and locking itself in.

There is a big difference between the A/C tripping into ATTI mode when still in range of the R/C where manual control can be gained as opposed to being out of range where manual control is not possible.

The option of RTH when signal is lost is set in DJI GO and LITCHI. So why does the option change to hover when the mission aborts itself and the signal is lost?

If there is a rep from DJI or LITCHI reading this then please feel free to answer.

Sent from my STV100-4 using PhantomPilots mobile app