Litchi app on Android

Kaehn · May 19, 2015

The way the video is connected is by calling a simple "connectToDrone", the rest is all handled inside the SDK and we have no control over it including the automatic reconnection. If you want to disconnect from the drone, you call the similar function 'disconnectToDrone', that will reset everything, not just the video connection. Regarding the video itself, all we get access to is a h264 frame buffer via a callback, then we pass it back to the C decoder. Assuming the video callback containing the buffer keeps getting called when there is a problem (it probably isn't), we could potentially as you said compare it with the last frames and see if nothing changed after a certain amount of time. But this sounds like a lot of work for the app to do pretty much constantly, for something that DJI really needs to fix themselves. After all the official app does not have this issue, or at least it happens much less often.
We totally understand how frustrating it is, something must not be playing nice between the sdk and your setup, I personally do not have a lot of video disconnect/reconnect issues, and I am sure I'm not the only one.

Wheelie · May 19, 2015

@ ctrlbrk

i had a very similar problem with my nexus 7, a simple frame rate adjustment cured it all, my post on the prob below.

@Kaehn.......My first post to congratulate you on this awesome app, nice n easy to use and looks very sharp indeed. Had a few problems on initial setup with my Google Nexus 7 (Gen 2) running 4.4.4 but got that sorted with some research on this and other Phantom forums. The problem i had was the app freezing, very pixilated screen and wifi dropping out making the app unusable when my bird was in the air but a simple change in settings in the app to 640x480 15fps (from 30fps) cured everything and the app worked perfectly all weekend so anyone out there having problems with their Nexus 7 just change the frame rate to 15fps and all will be good.

Kaehn · May 19, 2015

Yep I also use 640x480 15 fps, and I recommend using that.

ctrlbrk · May 19, 2015

Kaehn said:
Yep I also use 640x480 15 fps, and I recommend using that.

I've tried 320x240 15 fps, 320x240 30fps, 640x480 15fps. None of them work for long and there is no correlation with range and when the video stops.

StevenQX · May 19, 2015

For me the best resolution is 320*240@30fps, I prefer more smoothness than pixel but are tastes!

Diirk · May 19, 2015

Will Litchi on Phantom 3 also have a range booster? Or is that only possible with the P2 range extender?

Kaehn · May 19, 2015

We don't know what can be done at this time as we have not looked into it yet. But it's very different from the P2 so the same booster won't work.

GSSP · May 21, 2015

Bump for the best APP

jensemann · May 22, 2015

First of all MANY thanks for this great app; purchased it yesterday and give it a test flight this morning in sunny, could windy south germany

, could not wait any longer after the rain...

Feedback (+ / o / -):
+ in general: ui is excellent, responsive, easy to use, well done
+ FPV tested in 640x480 with Sony Xperia Z2 Lollipop, excellent
+ GS tested, all good, video link with 750m, bank turns are great !
o could not distinguish between recording or standby (the 2 red symbols...) - may add flashing if rec active?

Bugs:
- follow me, gimble "oscillates".. moves up and down (looks like "searching for me

) while follow me active - please investigate
- follow me, P2V flew away in opposite dir once activated, I cancelled the operation with ATTI - GPS (I will try again to see if mobile gps was an issue)

Questions:
- what happens in follow me if mobile GPS "jumps" let say 100m ? do you interpolate and validate if a new possision is reasonable (not possible to have a jump of xx m within xx seconds, so hover..)
- what happens in follow me if connection to remote gets lost (off, low batt..) - RTH ? HOVER? RTH might not be expected in this case..
- the max flight distance from DJI is not used if GS points are > this limit correct ?

Feature Request:
- what about a question during start if map around curr. mobile position should be cached while on mobile network, before connecting to Phantom wifi?
- what about asking if Airplane mode should be actived & wifi ? Dont know if that is possible w/o root rights

Hope you understand my german english.. sorry

Kaehn · May 22, 2015

Hi jensemann,

For the record button flashing, we made many UI changes recently, a lot of them aren't in the public release yet. See this video

This video shows the current state of things for the UI for P3/I1. For P2 the UI is a little different, we now show the record button and the take photo button at the same time on the screen, rather than having a switch.

Follow me is bugged with firmware 3.14, please do not use it, that's a known issue and we really want to fix that, at the same time it seems to be a bug in firmware 3.14. It works well with the same code with firmware 3.12. We've reached out to DJI and they answered us saying they will follow up, we are hoping they will fix it soon.
We have alerts telling users not to use it on our forums https://groups.google.com/forum/#!topic/vctechplus/SAPpcadZyC4 , on our site http://flylitchi.com/faq and in the play store description.

So if it jumps 100m and if it's wrong, the accuracy will be high, and by default if the accuracy is higher than 5, the location is ignored and the phantom will stop moving. In the latest alpha versions, we keep the last known good location for a bit longer which should make it more reliable, but again with firmware 3.14, nothing works as it should.
If connection is lost, phantom will RTH. If you have dynamic homepoint on, it will normally come back to you/your mobile device.

Which max flight distance are you talking about? Generally our app does not have any limit.

If your wifi is disabled when starting the app, the app won't automatically connect to the phantom, and by doing that you could first cache maps, then tap the top button to connect (which will take care of everything including enabling wifi if its not enabled).
For airplane mode, since it also disables wifi, I think it would be a little annoying and could easily lead to problems. I personally never put airplane mode while flying too so it would have to be an option.

jensemann · May 22, 2015

thanks for your reply..
- i will stop using follow me for now, topic understood
- the flashing circle would be a great improvement to see if it's recording!
- max flight distance = "Distance Limits" in PC app:

- sorry being unprecise with my auto cache map feature.. this was the idea:

precondition: mobile device is connected to internet and gps fix available

- app starts,
- while app waits for the phantom wifi, map autozooms xxxx m around my gps pos
- optionally, app toggles map and sat view to cache both
=> this will cache enough map around my position !
- app detects phantom wifi, asks to connect

Kaehn · May 22, 2015

For the max flight distance, I'm honestly not sure, something to test. I would assume the phantom won't go past that max distance even if we ask it to. I don't believe this value is exposed through the SDK though so not much we can do in terms of warnings.

I see what you mean about map caching, though it would probably be difficult to implement. Auto zooming to cache maps sounds cool however if say your internet speed is abysmally slow, it will take time to cache the map at a given zoom level, and as far as I know there is no way for us to know if the maps are cached or not as Google does not make this available to developers.

G-unit · May 22, 2015

Hey guys, trying to get my flight date off my tablet,Nex7 2013, I cant find them, any ideas, I have the "enable Flight Logs" turned on. On my samsung i can find them, just cant with the nex7.
Any ideas ?
Thanks G

Kaehn · May 22, 2015

Try looking for the files directly on your device if you haven't, I had problems too with a nvidia shield, where they don't appear when connected to a PC, but they are there when I browse the files on the tablet via an app.

G-unit · May 22, 2015

Kaehn said:
Try looking for the files directly on your device if you haven't, I had problems too with a nvidia shield, where they don't appear when connected to a PC, but they are there when I browse the files on the tablet via an app.

Ok i will look on the tab without hooked to computer.
Thanks for the fast response.
G