send

R2026b

Send command to remote MAVLink client

Since R2026b

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    Syntax

    [status,ack] = send(command,mavlinkclient,commandMsg)

    Description

    [status,ack] = send(command,mavlinkclient,commandMsg) sends the MAVLink command message commandMsg to the remote MAVLink client mavlinkclient. The function returns the command send status and the acknowledgment message returned by the remote MAVLink client.

    Examples

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    Send a waypoint command to a Pixhawk® 4 board running PX4® firmware by using the command microservice.

    Create a mavlinkdialect object using the common.xml file.

    dialect = mavlinkdialect("common.xml");

    Create a local MAVLink client by using the mavlinkio object.

    gcs = mavlinkio(dialect);

    Store the remote MAVLink client information by using the mavlinkclient object. This Pixhawk board has a system ID of 1 and a component ID of 1.

    uav = mavlinkclient(gcs,1,1);

    Connect the local MAVLink client to the same serial port as the Pixhawk board by using the connect function. This Pixhawk board uses the COM5 port.

    connect(gcs,"Serial",SerialPort="COM5");

    Create a heartbeat microservice object.

    heartbeat = mavlinkmicroservice(gcs,"heartbeat");

    Start sending the HEARTBEAT messages to the Pixhawk board by using the start function.

    start(heartbeat,uav,"Serial",SerialPort="COM5")

    If the Pixhawk board replies with HEARTBEAT messages, a connection is established.

    Verify that the connection has been established by using the listClients function.

    listClients(gcs)
    ans = 2×4 table
    SystemID    ComponentID       ComponentType             AutopilotType     
    ________    ___________    ____________________    _______________________

      255            1            "MAV_TYPE_GCS"        "MAV_AUTOPILOT_INVALID"
       1             1         "MAV_TYPE_QUADROTOR"       "MAV_AUTOPILOT_PX4"

    Create the waypoint command message structure by using the createcmd function.

    cmdMsg = createcmd(dialect,"INT","MAV_CMD_NAV_WAYPOINT")
    cmdMsg = 

  struct with fields:

      MsgID: 75
    Payload: [1×1 struct]

    Specify these parameters of the waypoint command message:

    • Acceptance radius — 2 meters

    • Latitude — 42.2831 degrees

    • Longitude — –71.3468 degrees

    • Altitude — 50 meters

    For more information on the waypoint command parameters, see the MAV_CMD_NAV_WAYPOINT section of the MAVLink documentation.

    cmdMsg.Payload.param2(:) = 2.0;
cmdMsg.Payload.param5(:) = 42.2831;
cmdMsg.Payload.param6(:) = -71.3468;
cmdMsg.Payload.param7(:) = 50.0;

    Create a command microservice object.

    command = mavlinkmicroservice(gcs,"command");

    Send the command message to the Pixhawk board by using the send function. The function returns the status and the acknowledgement message sent by the Pixhawk board.

    [status,ack] = send(command,uav,cmdMsg)
    status = true
ack = 
  struct with fields:

             command: 16
              result: 0
            progress: 255
       result_param2: 0
       target_system: 1
    target_component: 1

    Input Arguments

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    Command microservice, specified as a commandMicroservice object.

    Remote MAVLink client information, specified as a mavlinkclient object.

    MAVLink command message to send, specified as a structure with these fields:

    • MsgID — Message identifier, specified as 75 for COMMAND_INT commands, or 76 for COMMAND_LONG commands.

    • Payload — Structure with fields corresponding to the specific command definition.

    Tip

    Create the command message using the createcmd object function of the MAVLink dialect object.

    Data Types: struct

    Output Arguments

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    Command send status, returned as a 1 or 0 of data type logical. The value is 1 (true) when the local MAVLink client receives the acknowledgement message without exceeding the maximum time and number of retries.

    Data Types: logical

    Command acknowledgement message, returned as a structure with these fields:

    • command — Command identifier, returned as an integer corresponding to a value in the MAV_CMD enum.

    • result — Command result, returned as an integer corresponding to a value in the MAV_RESULT enum.

    • progress — Progress percentage when the result is MAV_RESULT_IN_PROGRESS. Values range from 0 to 100, or 255 if the progress is unknown.

    • result_param2 — Additional result information.

    • target_system — Remote MAVLink system ID, returned as an integer in the range [1, 255].

    • target_component — Remote MAVLink component ID, returned as an integer in the range [0, 255].

    Tip

    To view the available MAV_CMD enum values, use the enuminfo function. For example, to find the values of the MAV_CMD enum:

    info = enuminfo(dialect,"MAV_CMD");
info.Entries{:}
    where dialect is the MAVLink dialect object that you specify when you create the local MAVLink client.

    Version History

    Introduced in R2026b

    See Also

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    External Websites