Mavlink2 command ack failed


  • I tried to send a mavlink2 command: PROTOCOL_VERSION. And I get COMMAND_ACK with result 4.
    result 4 mean to (by NAV_RESULTS) NAV_RESULT_FAILED.
    COMMAND_ACK {command : 512, result : 4}

  • When i sent a command like FLIGHT_INFORMATION. I didnt get anything.

  • I wanted to point out that AUTOPILOT_VERSION Emitter the MAV_PROTOCOL_CAPABILITY_MAVLINK2 flag on.

I used c_library_v2
serialx_protocol = 2
arducopter 4.0.7

The wireshark display that all the messages are mavlink2 protocol type.
What could be the problem that i can’t send and receive mavlink2 message?

You are probably using the upstream mavlink documentation GitHub - mavlink/mavlink: Marshalling / communication library for drones. instead of ardupilot`s fork GitHub - ArduPilot/mavlink: MAVLink micro air vehicle marshalling / communication library.
Please use our fork.

And update to ArduCopter 4.2.2-rc1 or newer. Not all mavlink commands are supported, but the support improves in every version.