How to find the clients connected with MAVSDK Server?

[MuhammadBilal1]

I am running the Gazebo Headless Simulator with the below command.

docker run --rm -it jonasvautherin/px4-gazebo-headless:1.10.1

After successfully running the simulator, I tried to ran the example. python mission.py This example ran successfully.

But when I try to ran the mission example from my own application (basically a Django application with Celery for running MAVSD in background) If I get any problem while running the example, after the error I am unable to connect with the Drone (Gazebo Headless Simulator). I tried to stop the simulator and started again, but still not working.

1- How to check is there any client connected with MAVLINK? 2- If an error came while running the example and program failed without completing the "Landing", the problem didn't able to connect with the drone after the error.

[MuhammadBilal1]

@julianoes @JonasVautherin Can you please help me with the above problem.

[JonasVautherin]

I'm not sure what kind of error you are referring to. You mean that mission.py crashes?

[MuhammadBilal1]

Error is appearing while executing the mission.py from my Django application via Celery.

Error is coming while uploading the mission to the connected drone. Now, after getting this error, I can't connect to the drone again until I restart my Operating System, or I close all my terminal windows, which are running Django/Celery/Gazebo HeadLess Simulator.

Problems: 1- Getting the Operation Timeout error at upload_mission() as shown in the below image while running the mission.py. 2- After getting the operation timeout error, mission.py remains stuck at Waiting for Drone to connect....

[MuhammadBilal1]

Somehow I managed to get the list of ports that were in use when I am unable to connect with the Drone. Please see the attached snapshot for details. I need help in resolving the Operation Timeout error of mission.py

[JonasVautherin]

Maybe you should try to run mavsdk_server manually, with:

./mavsdk_server -p 50051 udp://:14540

And in Python, you need to connect to it by changing the System() line:

drone = System(mavsdk_server_address='localhost', port=50051)

[MuhammadBilal1]

I am unable to start the mavsdk_server manually, can you please tell me from where I need to run this command? Please see the attached snapshot.

[julianoes]

You can look for it:

find . -name mavsdk_server

For me, the one installed using pip is here:

~/.local/lib/python3.8/site-packages/mavsdk/bin/mavsdk_server

[MuhammadBilal1]

@julianoes Thank you for your support. I installed the mavsdk using the pip, and my installation is also available at the same place. I went to that directory and started the mavsdk_server manually. The server started successfully.

My issue is resolved and I am not getting the Operation timeout error anymore while running the mission.py example.

I started the things in the following order, and everything worked fine.

1- Started mavsdk_server manually from your given command. Ran successfully. 2- Started the Gazebo Headless simulator. Ran successfully. 3- Started by application (Django). Ran successfully. 4- Started Celery. Ran successfully. 5- Triggered the method which was calling the mission.py. It also ran successfully.