parameterMicroservice

R2026b

MAVLink Parameter microservice

Since R2026b

Description

The parameterMicroservice represents the MAVLink Parameter microservice. This object uses MAVLink parameter protocol messages to read parameters from, and write parameters to a remote MAVLink client. Use the object functions to read and write parameters, or to configure timeout and retry behavior for parameter operations.

Creation

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

parameter = mavlinkmicroservice(mavlinkio,"parameter")

Properties

Timeout — Parameter operations timeout

2 (default) | positive scalar

Parameter operations timeout, represented as a positive scalar. This property determines the maximum time, in seconds, that the parameterMicroservice object waits for required MAVLink messages, such as acknowledgments or parameter values, before retrying a parameter get or set operation. This property is read-only. To set this property, use the setTimeout function.

Retry — Parameter operations retry count

3 (default) | nonnegative integer

Parameter operations retry count, specified as a nonnegative integer. This property determines the number of retry attempts for parameter get or set operations that do not complete within the timeout period. This property is read-only. To set this property, use the setRetry function.

Object Functions

set	Write parameter value to remote MAVLink client
get	Read parameter value from remote MAVLink client
setTimeout	Set microservice timeout value
setRetry	Set microservice retry count

Examples

Tune Maximum Yaw Rate Parameter of Pixhawk Board

Tune the maximum yaw rate parameter of a Pixhawk^® 4 board running PX4^® firmware by using the parameter 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. If the remote MAVLink system replies with HEARTBEAT messages, a connection is established.

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 a parameter microservice object.

parameter = mavlinkmicroservice(gcs,"parameter");

Obtain the current value of all parameters by using the get function.

[status,param] = get(parameter,uav)

status = true
param = 10×5 table
    param_value   param_count    param_index       param_id           param_type     
    ___________   ___________    ___________    ______________    ____________________
        0             942            12         SYS_AUTOSTART             6            
        1             942            22         COM_ARM_WO_GPS            6            
      300             942            50         COM_RC_LOSS_T             9            
     15.5             942            88         BAT_LOW_THR               9            
     12.0             942           105         MPC_VEL_MAX_UP            9            
      5.0             942           106         MPC_VEL_MAX_DN            9            
      2.5             942           315         NAV_ACC_RAD               9            
      200             942           412         MC_YAWRATE_MAX            9            
      0.5             942           413         MC_PITCHRATE_P            9            
      0.1             942           418         MC_ROLLRATE_I             9            

Obtain the current value of the MC_YAWRATE_MAX parameter. The output shows that the current maximum yaw rate of the Pixhawk board is 200 degrees per second.

[status,param] = get(parameter,uav,"MC_YAWRATE_MAX")

status = true
param = 1×5 table
    param_value   param_count    param_index       param_id           param_type     
    ___________   ___________    ___________    ______________    ____________________
       200            942            412        MC_YAWRATE_MAX            9          

Specify a new maximum yaw rate parameter value of 150 degrees per second by using the set function. The function returns the updated parameter value to verify the success of the parameter set operation.

[status,param] = set(parameter,uav,"MC_YAWRATE_MAX",150)

status = true
param = 1×5 table
    param_value   param_count    param_index       param_id           param_type     
    ___________   ___________    ___________    ______________    ____________________
        150           942            412        MC_YAWRATE_MAX            9          

Version History

Introduced in R2026b