Ultrasonic Sensor Error & Joystick Mode

[tom351]

Yesterday I was flying my MPP from boat - just testing/comparing DJIgo ActiveTrack and Litchi's follow mode. My MPP was wearing these floats:
DJI Mavic pro Foldable Water Mod protector Yellow EDITION Drone ON Water Travel Edition

Everything was going fine for about 10 mins- after switching fron DJIgo to Litchi and back (while in air) I got a "Ultrasonic Sensor Error" as well as "Joystick Mode" on the RC. At the time I thought that the sensor error caused the joystick mode, but upon reading some old posts here I think that they may have been two separate issues that happened almost simultaneously. When both occurred, my MPP just paused in place (RC and app were still connected though) approx 30' above the water and my control sticks did nothing. I had signal loss failsafe set to hover and was prepared to just wait out the battery until it autolanded on the water. Then I thought to try RTH button and this caused the MPP to start a climb to RTH attitude- I did not want it to do this so I quickly flipped sport mode on/off to stop the RTH but this caused me to regain full control from the RC. I assume that I should have just tried sport mode toggle as soon as I was stuck in Joystick Mode.

My current thoughts: (please let me know if you disagree)
The ultrasonic sensor error was most likely caused by the floats/attachments.
The joystick mode was a separate occurrence likely caused by exiting Litchi while in follow mode.
These two issues just coincidentally happened at almost the same time (in fact, I think I exited Litchi as soon as I saw the sensor error- this abrupt app closure may have cause it to stick in joystick mode)


Does anyone think that I need to worry about the ultrasonic error in the future if NOT using the floats?

 

[MGS9500]

I will confirm that the ultrasonic error is from the floats. This is a known problem with all of the "add on" landing or support gear.
I have a device that interfered. I ended up trimming away all plastic near the sensor.

The sensor is very sensitive to any plastic or part that extends into it's field of view.

 

[netfolks2000]

I don't know about the technical aspects other than the previous reply about the floats and sensors, but I really see you taking a great risk with an expensive drone first by using two different apps while in flight. You have a great chance of losing signal and going into RTH, so those settings have to be right, like hover as an option, so you don't land in the water, even with floats, possibly far from your boat, with waves perhaps even out of sight. Is it worth all those risks?

 

[tom351]

I don't know about the technical aspects other than the previous reply about the floats and sensors, but I really see you taking a great risk with an expensive drone first by using two different apps while in flight. You have a great chance of losing signal and going into RTH, so those settings have to be right, like hover as an option, so you don't land in the water, even with floats, possibly far from your boat, with waves perhaps even out of sight. Is it worth all those risks?

I have considered this- I do set the drone to "hover" instead of RTH if RC signal is lost. Also, when I switch apps the RC stays connected- sometimes it takes a few seconds for the newly launched APP to connect, but as long as the RC is connected and I have LOS it is not a big concern- that is until "Joystick Mode" happened, but at least now I know how to get out of it.

Also, no waves- was on a lake, no other boats within sight, and drone was never more than 150 feet away from me.

 

[MavicCF]

I have considered this- I do set the drone to "hover" instead of RTH if RC signal is lost. Also, when I switch apps the RC stays connected- sometimes it takes a few seconds for the newly launched APP to connect, but as long as the RC is connected and I have LOS it is not a big concern- that is until "Joystick Mode" happened, but at least now I know how to get out of it.

Also, no waves- was on a lake, no other boats within sight, and drone was never more than 150 feet away from me.

Interesting occurrence. The only time I have ever seen "joystick mode" on the controller screen is when I'm using the Litchi VR in, well, Joystick mode. Obviously that wouldn't make any sense in your case as you weren't flying with VR goggles. I also usually exit it by flipping into sport and back. I wonder if there is some bug in the system somewhere?