"Cannot Take Control" error message - Mavic Pro - Android
So I went out today to try my first dronelink flight, a simple mapping of a nearby field that I use for testing all new drone software. It didn't quite go as planned ...
Phone: LeEco Pro3 AI
OS: Android 6.0
Drone: Mavic Pro
- I connected with DJI app, ran an update including no fly zone database.
- A short test flight just to check everything is working.
This gave me a class D restricted airspace warning, saying I was near a refinery that is over 100 miles away! I've submitted this as an error to DJI. The warning disappeared after a few seconds and I was able to continue the manual flight as expected. - I disconnected everything and restarted using dronelink. Selected a pre planned simple mission and hit [play]
After a few seconds the drone took off to 1m and then stopped. The phone display showed an error alert saying "Cannot Take Control [OK]" - I landed the craft and tried again a few times with the same error.
Now I suspect this is to do with the incorrect NFZ, but the error message could have been more helpful.
Immediately after this I ran the same mission using Litchi, this controlled the drone fine and completed successfully. Although the controller display showed "NFZ error" on the screen for part of the flight.
I'm not near any airport, the nearest actual NFZ is a small prison over 6km away. No NOTAM's were listed in the area.
I'll try again in a few days (if we get any suitable weather) and hopefully DJI will have corrected the data, assuming that was the cause?
Should dronelink refuse to work like this in class d space?
Cheers
Comments
9 comments
That error message happens when Dronelink is not able to put the aircraft in to "Joystick" mode. Do you remember seeing what mode the RC said the aircraft was in? Did you have the flight mode switch set to P?
Everything is pretty much set as "out of the box" on the mavic.
Sport mode was not switched on (so I think that is P yes?).
GPS signal was strong (around 16 connected at the time) and the controller was "GPS mode" before I selected to start the mission.
The only other thing I can think of is outdated firmware. Have you tried another app like Hangar 360 or Autopilot (that uses the virtual stick interface in the DJI SDK)?
Thanks for the response!
The firmware was updated the day before so should be fine.
Hangar 360 and autopilot seems to only be iOS, is that right? Unfortunately I'm Android only.
DJI Go, Litchi and an old version of PrecisionFlight were all ok, the first two I was flying with onscreen virtual joysticks (Is that the same thing and using the SDK?) and the second two both ran an automated mission.
The only other thing I can think might affect it is the exp/sensitivity/gain of the controls set in DJI Go were all adjusted slightly but I guess that would be overridden at flight time.
When you use the on-screen virtual joysticks does the RC say "Joystick" as the mode?
No, Just GPS Mode, ATTI Mode or NFZ Error.
Looking through the Mavic Pro manual (page 63 below) there doesn't appear to be a "Joystick" display status, but this table doesn't include the "NFZ error" I saw, so it isn't exhaustive
https://dl.djicdn.com/downloads/mavic/20171219/Mavic%20Pro%20User%20Manual%20V2.0.pdf
If the RC never reads "JOYSTICK" then Dronelink will not be able to take control. It is possible that it is specific to the Mavic Pro only, in which case we will need to track down our test unit and give it a shot, but no one else is reporting any issues like this.
Hi Jim. I've just got back from a quick test using the same location, devices, software, firmware and mission.
Today of course it (almost) worked and took control, showing "Joystick" on the controller. The aircraft took off and flew to the start point successfully.
The mission still failed though, with an error of:
Camera Photo Interval | 3 seconds | Param Illegal
I'd used the default settings in Dronelink for Mavic Pro, which is actually "2 seconds" but I'll have a fiddle and try longer "Min Capture Intervals".
My only real question now is whether it should fly in class D airspace OK as I have a client mission that requires it and I'd like to use dronelink, but this might be a showstopper.
FWIW, DJI Go didn't erroneously warn me today about an NFZ
Thanks for the help
So, I've a bit more info and to wrap this thread up if anyone comes across it later...
There was a drone "incident" near a refinery in the UK a week ago. DJI put a TFR around the site, but an error in their system seems to have extended this for about 100 mile radius for some users (while not showing it on any map, either flysafe or in Go4)
Since the TFR was removed everything seems to work, but while it was in place dronelink gives a "Cannot Take Control [OK]" error.
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