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Litchi 2.7.0 problem

Raoul

Active Member
Join
May 16, 2019
Messages
31
Age
37
Loc
Italy
Hello all,

this morning, after a couple of months when I didn't have the chance to fly, I wanted to test the 2.7.0 version of Litchi. The first problem I encountered was at take-off: I pressed icon for automatic take-off and after giving the confirmation nothing happened, the Spark remained still on the ground without even turning on the engines. I thought I had made a mistake and had not given the confirmation, I do everything again as before, but the Spark does not move. Ok, I try with the manual take-off with RC and this time everything goes well. I try to do some quick movements to see if the bird responds to commands and there don't seem to be any problems. At this point I move it far enough (about 500 meters) and, with the 65% Spark radio signal, I press the RTH button. After the confirmation, as happened for the automatic take-off, nothing happened. I proceed with the RTH again, but nothing happens. The signal is strong enough, so I exclude that it could not have received it. On the fifth attempt, the app begins to signal me that the RTH has been activated and in fact the Spark was on the way back. After shutting down the engines I tried again to take off automatically and this time it worked the first time.
I wanted to test some automatic procedure of the app, but I would first like to understand why both takeoff and RTH have had problems. I repeat, I exclude that there may have been interference as the take-off took place at two meters from my RC and at the time of the RTH request the Spark was fully controllable and with the 65% radio signal.
I remembered something that happened yesterday about Gimbal. I had set one of the RC function keys to change the position of the camera by 90 degrees, but after setting and trying it hadn't worked. I had then done other things that were not related to the cam, but when I went to try the switch again at 90 degrees it worked. It is not the same thing, but it is as if at the first request the command did not work while it subsequently became available.
I thank in advance anyone who will help me.
Raoul

Aircraft 01.00.1000
RC 01.00.0600
GO 4 4.3.24
Litchi 2.7.0
iPad Mini 4
IOS 13.2

p.s.: sorry for Eng language, I am italian
 
Your English is infinitely better than my Italian. Do the RC commands work correctly with Go 4?
 
I purposely went out today to test Litchi for you, and ended up only doing a short test, because some neighbors walked up to me at the field I was in - they were fascinated by my Spark, so I landed and chatted with them, and ran out of time for testing.

I did run two missions perfectly fine. I even used the "auto take off", I had never used that before. The auto take off worked, the missions flew as programmed, following all commands I included.

The setup I used:

DJI Spark
Litchi 2.7.0
Pixel 2 XL (Android)

I'll try my iPad next time.
 
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Hello all,

today I did a complete test with Go 4 and Litchi and I had no problems, both with automatic operations and waypoint missions. I don't know what to say, I don't know why yesterday Litchi behaved in such a strange way. I hope it was just a strange radio interference (but I don't believe it much). In case it happens again I will try to get as much data as possible to find the reason.
Thanks again to all of you for assistance.
Raoul
 
This morning another strange thing happened. I wanted to take some panoramic photos from a certain height, but at some point my Spark started for no reason to move quickly to the northwest. After a few moments in which I verified that I had not given any command to make it move, I promptly entered the RTH mode and the drone returned without problems. I subsequently verified the log (attached) and saw no reason why my bird should go away. The only thing I noticed is that the wind was blowing in the same direction as the Spark, but with 18 satellites how did the drone ignore the GPS position?
Do you have any ideas? Thanks
 

Attachments

  • 2019-11-09_11-08-02_v2.zip
    104.7 KB · Views: 5
Do you use Airdata.com? It lets you look at your own fight data on-line. I have imported your flight into "my" Airdata account so you can look at it. Click here:
If you click on "Notifications" near the top, then scroll down, you can see you whole flight, which looks like it was 3:57 total.

At 0:55, it says there was a Data Loss for 1.1 seconds. Normally, not a big deal, but considering where you were (open field), there shouldn't have been anything in the way to cause this. Was there? Were your antennas aimed perpendicular (90-degrees) towards the aircraft? I'm assuming you were using a remote-control. Or were you using just your phone (Wifi) for controlling the aircraft?

I don't see anything else wrong with the flight. At which point did it start flying NorthWest by itself?

Another neat thing about AirMap is if you click on HD FLIGHT PLAYER, then click the blue "play" button, it will run you through your flight, while simultaneously scrolling all the data across the bottom of the screen. Hope this helps.
 
Hello Jimlips,

thank you for reply. Yes, I use the RC for manual spark control, but all the automatic operations are performed by Litchi via iPad.
At this address


I can upload my log file and I can see all my flight and all remote control positions at any time. I also saw that momentary interruption of the connection. I honestly don't know what it may be because the antennas were horizontal and the signal strong enough, but I don't think it could be the cause of the drone's shift towards NW. I also thought that the Spark, having climbed up, could have encountered stronger winds that he could not resist, but then how did he go back when I requested the RTH?
 
Hi Haggy,

if you watch my flight, I only let my Spark go vertically, so I think it is correct to have left my antennas horizontally.
 
Hi Haggy,

if you watch my flight, I only let my Spark go vertically, so I think it is correct to have left my antennas horizontally.
Yeah, I know..my response was just general. Sorry for the confusion.
If you check @jimlips Airdata sheet, Weather->Inflight wind and Wind map, you will see your Spark encountered wind/gusts close to max speed at altitude 200-300 m.
You where very lucky it could make it HOME. In RTH, do not forget to push forward on your stick to gain higher speed towards your HP position.
Use UAV Forecast app next time.
 
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Hi Haggi,

thank you for the clarification and for the explanation. I completely agree with you that I risked losing my drone, but at this point I would like to understand why I didn't lose it. The answer could be useful to all of us, if anyone ever encountered the same problem in the future and didn't know how to get out. If the Spark has encountered winds that are beyond its ability to maneuver and no longer manage to hold the position, why did the RTH command manage to overcome the problem?
To begin with I see that the first thing he does in RTH mode is not to reduce the altitude and bring it to the one set in the RTH preferences (why doesn't it start to go down?), but he tries to position himself at the Home Coordinates and then the descent begins. It is therefore to be excluded that it may have been helped by a decrease in altitude.
The only thing he does when he enters RTH is the rotation and pointing of the bow towards the HC. Is it possible that traveling with the bow facing the destination allows the drone greater efficiency and power? Would it have sufficed me then puts the bow of the Spark upwind so as not to move it from its initial position?
What do you think?
 
Hi Haggi,

thank you for the clarification and for the explanation. I completely agree with you that I risked losing my drone, but at this point I would like to understand why I didn't lose it. The answer could be useful to all of us, if anyone ever encountered the same problem in the future and didn't know how to get out. If the Spark has encountered winds that are beyond its ability to maneuver and no longer manage to hold the position, why did the RTH command manage to overcome the problem?
To begin with I see that the first thing he does in RTH mode is not to reduce the altitude and bring it to the one set in the RTH preferences (why doesn't it start to go down?), but he tries to position himself at the Home Coordinates and then the descent begins. It is therefore to be excluded that it may have been helped by a decrease in altitude.
The only thing he does when he enters RTH is the rotation and pointing of the bow towards the HC. Is it possible that traveling with the bow facing the destination allows the drone greater efficiency and power? Would it have sufficed me then puts the bow of the Spark upwind so as not to move it from its initial position?
What do you think?

The RTH algorithm is complex and difficult to explain in words. See the chart below to understand better. As you can see, if the drone is more than 20m away from home point, the drone will check if the altitude is below "failsafe altitude" (RTH altitude). If the altitude is less, it will rise to RTH altitude. If the altitude is already more than RTH altitude, it will RTH at that altitude itself. This is what happened in your case.

RTH flowchart.jpg
 

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