commandMicroservice

R2026b

MAVLink Command microservice object

Since R2026b

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

Timeout — Command send timeout

2 (default) | positive scalar

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.

Retry — Command send retry count

3 (default) | nonnegative integer

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

send	Send command to remote MAVLink client
setTimeout	Set microservice timeout value
setRetry	Set microservice retry count

Examples

Send Waypoint Command to Pixhawk Board

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