Bidirectional mavlink communication without using QGroundStation and ArduCopter

[SzateX]

Hi, I'm trying to communicate my drone with ground station. Drone should send video data, and mavlink messages to GS, and GS should send commands into drone. I'm not using QGroundStation and ArduCopter, I'm using my own software.

Now working communication from Drone to GS.
The drone settings are set to:

[drone_mavlink]
peer = 'listen://0.0.0.0:14550'

[drone_video]
peer = 'listen://0.0.0.0:5602

and GS settings are set to:

[gs_mavlink]
peer = 'connect://127.0.0.1:14550'

[gs_video]
peer = 'connect://127.0.0.1:5602'

On Drone I'm trying to bind 14550 UDP Port for reading mavlink communicates, but i'm unable to do it.
Have you some advices for make my communication two way?

[lucasgrelaud]

Could you test the connection with the wfb-cli tool to check if the link is established ?
You should a least see activity on the IP tunnel if the connection between the drone and gs is properly established.
I had issue in the past with mismatched drone and gs keys and this tool help me to figure it out.

Also, could you send us the log generated by the systemd service daemon?
You can access it using "sudo journalctl -u [email protected]"

[SzateX]

In log rather not special: .

wfb-cli shows me that connection works ok. The video shows as well without any problems, and mavlink communication from drone to gs works as well... Problem is when I'm trying to bind 15550 port on UDP to read messages on Drone I got: Port already in use. And I have no idea how solve this problem. I need two way communication via mavlink, because i have to set my camera settings by mavlink

[svpcom]

[drone_mavlink]
peer = 'listen://0.0.0.0:14550'

listen means that WFB is listening (bind to) UDP port. Add it as endpoint to mavlink router (mavlink-routerd -e 127.0.0.1:14550 /dev/ttySxx:uart_speed).

If you want WFB to connect to some port, use connect:// url

[svpcom]

Run mavlink-routerd -vv to debug packets flow

[SzateX]

Use listen in config on drone side, because if you have connect on the both ends you can not be able to establish mavlink connection because WFB doesn't emit new packets (only transmit them) and GS and drone's mavlink router will deadlock (because they both are listen for peers)

Decide. Listen or Connect.

No. In this config mavlink-router and WFB both listen 14550.
You need to use mavlink-routerd -e 127.0.0.1:14750 -e 127.0.0.1:14550 0.0.0.0:14551 or use

[drone_mavlink]
peer = 'connect://127.0.0.1:14550

If i run this mavlink-router command it still doesn't work. Sending packets from drone (drone is writting to: 127.0.0.1:14550) to gs (gs is listening 0.0.0.0:14550) works. From gs (gs is writting to 127.0.0.1:14550) to drone (drone is listening 0.0.0.0:14750 and mavlink-routerd -vv -e 127.0.0.1:14750 -e 127.0.0.1:14550 0.0.0.0:14551 applied). No output on mavlink-router.

[svpcom]

GS should not write to 127.0.0.1:14550, but should use source ip and port of received udp packets to send replies. See mavlink router sources for reference.

[SzateX]

Now if I do like you say, I got one message from drone to gs. And all communication freezes (I need to restart service to go again)

[svpcom]

If connect QGroundControl in parallel to your app - is it working?