commandMicroservice

R2026b

MAVLink Command microservice object

Since R2026b

expand all in page

    Description

    The commandMicroservice represents the MAVLink Command microservice. This object uses MAVLink command protocol messages to send commands to a remote MAVLink client. Use the object functions to send commands or to configure timeout and retry behavior for command operations.

    Creation

    To create a commandMicroservice object, use the mavlinkmicroservice function and specify the microservice type as "command":

    command = mavlinkmicroservice(mavlinkio,"command").

    Properties

    expand all

    Maximum time, in seconds, that the commandMicroservice object waits for acknowledgment message before retrying to send a command, specified as a positive scalar. To change this value, use the setTimeout function.

    Number of retry attempts for sending a command that do not complete within the timeout period, specified as a nonnegative integer. To change this value, use the setRetry function.

    Object Functions

    sendSend command to remote MAVLink client
    setTimeoutSet microservice timeout value
    setRetrySet microservice retry count

    Examples

    collapse all

    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

    Version History

    Introduced in R2026b

    See Also

    | | | |

    External Websites