VERY scary event with the I2 and Litchi App

LaunchHSV · Apr 15, 2017

So, I had a very scary event today. I went in the back yard to test the I2 with Litchi and do a panorama. This was my first time using litchi on the I2 and I have used Litchi on the Mavic Pro with great success.

I upgraded the Firmware last night on the I2 and Litchi is up to date as well.

I was mid panorama maybe 12 pics in when the app shutdown and sticks were DEAD!!! I had no control over the aircraft.... Now, fortunately, it sat there like a good little drone 125ft above the grass stable and patiently awaiting my input. I closed the app completely out and opened DJI Go4 App also up to date. Still no joy on the sticks.

Well, I got to test the return to home feature for the first time today..... Unfortunately, it was in an emergency state and not a test.... She returned home safe and sound, but my heart was racing!!

I will never use the Litchi app on my Inspire 2 AGAIN........ EVER!!!!

Viper Pilot · Apr 15, 2017

Hmmmm, I wonder how using the Litchi app could have made your R/C sticks not function? Very unusual to say the least.

Viper Pilot · Apr 15, 2017

It was good you kept your wits and used the Go 4 app and commanded RTH.

LaunchHSV · Apr 15, 2017

I agree Viper, very strange to have dead sticks on just an app. I had full control (on the sticks) up to the point of the panorama (app took over). I had a green light on the RC signalling a conection to the drone, but no control.

I'm glad the app worked for RTH......

LaunchHSV · Apr 15, 2017

I want to also note that it didn't return to take off location but used its current location to set down. Because it was in the backyards green space it was clear of obstacles or people. Had this of happened on a job site this would be a different tune!

Phatzo · Apr 15, 2017

LaunchHSV said:
I agree Viper, very strange to have dead sticks on just an app. I had full control (on the sticks) up to the point of the panorama (app took over). I had a green light on the RC signalling a conection to the drone, but no control.

I'm glad the app worked for RTH......

you should send in something for the developers of litchi instead of ceasing the use of it. did you switch back to "P" mode where it cuts the connection to the automated feature?
it is good you did not panic but in your place i would give feedback to them and see if they can sort it out even if it was /is only you to have that problem at current time...

LaunchHSV · Apr 15, 2017

Phatzo said:
you should send in something for the developers of litchi instead of ceasing the use of it. did you switch back to "P" mode where it cuts the connection to the automated feature?
it is good you did not panic but in your place i would give feedback to them and see if they can sort it out even if it was /is only you to have that problem at current time...

I use Litchi religiously with the mavic to do quick work on job sites and am fully confident with it there. I will continue to use it with the mavic as well.

If anyone can point me to the developers I will be more than happy to provide input, even if it was user error I would like to know for future use and update this thread.

niki · Apr 15, 2017

You may not know but the aircraft can be controlled by the remote only, without the use of any app. The app is just an addition with extra futures.
From my experience every app is crashing at certain point and doesn't matter is it made by dji or 3rd party.
There was described procedure how to restart a crashed or freezing app.
1. disconnect USB cable
2. force close the app
3. reconnect USB cable
4. run the app

Reading of the user manual is really helpful for getting to know what you may expect and also how to proceed in such an event.

amorrison · Apr 15, 2017

Maybe switching to ATTI would have helped?

LaunchHSV · Apr 15, 2017

amorrison said:
Maybe switching to ATTI would have helped?

TBH I wasn't thinking of that at the moment, but that is a good point. The RC never broke connection but I did close out Litchi completely and successfully reconnect using DJI Go 4. You would think that would clear any errors.

I lost total control of the sticks (app or no app) RTH didn't even work on the controller.

PatrickP · Apr 16, 2017

LaunchHSV said:
TBH I wasn't thinking of that at the moment, but that is a good point. The RC never broke connection but I did close out Litchi completely and successfully reconnect using DJI Go 4. You would think that would clear any errors.

I lost total control of the sticks (app or no app) RTH didn't even work on the controller.

litchi...... ive heard too many horror stories to risk my bird. if there's an issue with the litchi app will the company accept responsibility? i've heard cases where DJI wont honor a warranty if you use 3rd party apps and an issue occurs.

PatrickP · Apr 16, 2017

PatrickP said:
litchi...... ive heard too many horror stories to risk my bird. if there's an issue with the litchi app will the company accept responsibility? i've heard cases where DJI wont honor a warranty if you use 3rd party apps and an issue occurs.

i forgot a while back I actually purchased litchi , but due to the negative stories never used it which is a bummer

i probably should have read up on it before wasting my money on the app

niki · Apr 16, 2017

LaunchHSV said:
TBH I wasn't thinking of that at the moment, but that is a good point. The RC never broke connection but I did close out Litchi completely and successfully reconnect using DJI Go 4. You would think that would clear any errors.

I lost total control of the sticks (app or no app) RTH didn't even work on the controller.

Probably everyone will have some level of panic when such a thing happens. But in litchi help is told that wen on a "mission" if the craft loose signal with the remote the craft will continue following the mission till he get back close to you and will automatically reconnect. One should consider that when planning the mission flight. Because if the case is as yours (freezing app during mission) the litchi will not be able to reconnect to the drone because the app was frozen. So then just do the 4 steps I've listed above plus additional step which is to turn the remote off and on as well.
To me personally it happened once with dji go. Hopefully for me the craft was on the ground and just ready to take off. Suddenly the go app changed its status to "disconnected" and I could not reconnect wathever I do even by the closing the app and reconnecting the USB cable. Then I've had to turn off and on the master remote and then the drone reconnected and was back in control.Very spooky situation but it has an explanation as well. Reading and knowing how radio communications as well computers and electronics work and in what circumstances they do not qork as expected is a very good addition to any drone pilot and operator.
I'm glad you saved your bird

Thatius Dudeson · Apr 16, 2017

Good god... where do you people live, so I can never go anywhere near there.

lake_flyer · Apr 16, 2017

LaunchHSV said:
TBH I wasn't thinking of that at the moment, but that is a good point. The RC never broke connection but I did close out Litchi completely and successfully reconnect using DJI Go 4. You would think that would clear any errors.

I lost total control of the sticks (app or no app) RTH didn't even work on the controller.

So you didn't switch to P mode as well?
That should have solved it. In fact you should have tested that switch before sending it on its first Litchi mission.

Updating the firmware right before trying out a new third party app is not the way. You should have tested the update first before trying anything new. Not that it is definitely firmware related but you want to be absolutely sure it functions 100%. I always conduct flight tests after any firmware update. You can even check everything on the simulator first (the I2 also has a sim doesn't it?), including the switching to RTH, F,P and Atti modes. If Go or the firmware would be screwed you would notice it even before you take it into the field..

Good that you managed to stay cool and save the situation. Next time I suggest you use the P/F switch to get out of autonomy when anything happens, and always do test procedures like I mentioned above and you will be fine for the future.

Viper Pilot · Apr 16, 2017

The I2 R/C does not have a simulator capability as yet nor does the Go 4 app.

NickU · Apr 16, 2017

I think you've been quite lucky...

First off, Litchi and a lot of the mapping/ground station Apps don't always control the drone in real-time - they upload a waypoint mission to the drone's memory and tell it to go fly it autonomously. If the Command link is lost momentarily or for longer, then the aircraft is usually set to continue the mission until the end point, then do whatever was set to happen at the end of the mission - return to home, land in place, hover etc. That's the case with Litchi and Panoramas too.

If you have an app crash, then best not to panic, first off - try switching to ATTI mode as that should instantly disconnect any autonomous flight plans from running and give you back control of the aircraft with the RC and sticks, then you can either fly back to you visually or land in place. Beware though that the aircraft may drift in the wind in that mode, so try switching back to P or Sport asap and that should stabilise you - the autonomous program shouldn't restart (if it does, then flick back to atti again). If still nothing is responding, at the very worst, turn off your RC and the Aircraft should return to it's original take off home point after a few seconds when it detects the loss of the RC command signals. It goes without saying, always check the right home point has been recorded at take off!

If you've regained control, then you can think about restarting the app.. but if you do that one thing to watch for is to be very careful of using the RTH function! When an App starts up it will often record the immediate current position of the aircraft as the new home point - if you hit RTH you may find the aircraft simply lands at the spot it's at (bad news if you're over water!), or if you've flown it after starting the app, returns to the spot the app was restarted at - not where you took off from! So, if you have to restart the app, you may need to check your home point on the map and reset it to the current controller position if it's not where you expect it to be!

BTW, ATTI mode isn't available on the Mavic, so can't blame you for not trying to switch to it on the I2!

Viper Pilot · Apr 16, 2017

NickU is totally correct and offers good advice. One other point, however, if you have an external GPS attached to your R/C, you can select that as the home point after you restart your R/C and Go 4 app and the I2 will return to that position when you select RTH. A very handy feature together with ATTI to get the thing back to you if Litchi or any other app crashes or freezes up.

Sligeach · Apr 16, 2017

Just a thought, if you start up the DJI go app, when the aircraft is already in flight I think it would use the position where the Aircraft is as it's home point. You can go and set the home point to the location of the controller in the Go app, which should then allow the RTH to work as it should.
Also, as far as I know Autopilot sends signals in realtime, rather than uploading the mission, unless you specifically tell it to, so that might help.