connect

Connect to MAVLink clients through UDP port

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Syntax

connectionName = connect(mavlink,"UDP")
connectionName = connect(___,Name,Value)

Description

connectionName = connect(mavlink,"UDP") connects to the mavlinkio client through a UDP port.

example

connectionName = connect(___,Name,Value) additionally specifies arguments using name-value pairs.

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Examples

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Open Live Script

Connect to a MAVLink client.

mavlink = mavlinkio("common.xml");
connect(mavlink,"UDP");

Create the object for storing the client information. Specify the system and component ID.

client = mavlinkclient(mavlink,1,1)
client = 
  mavlinkclient with properties:

         SystemID: 1
      ComponentID: 1
    ComponentType: "Unknown"
    AutopilotType: "Unknown"

Disconnect from client.

disconnect(mavlink)
Open Live Script

Create a MAVLink dialect object using the common.xml file.

dialect = mavlinkdialect("common.xml");

Create a local MAVLink client object that represents a simulated UAV. Specify these options:

  • MAVLink message definition — dialect

  • MAVLink system ID — 1

  • MAVLink component ID — 1

  • MAVLink component type — MAV_TYPE_QUADROTOR

  • MAVLink autopilot type — MAV_AUTOPILOT_GENERIC

uavClient = mavlinkio(dialect,SystemID=1,ComponentID=1,AutopilotType="MAV_AUTOPILOT_GENERIC",ComponentType="MAV_TYPE_QUADROTOR");

Connect the local simulated UAV to a random open UDP port by using the connect object function.

connect(uavClient,"UDP");

List all MAVLink clients that are connected to the simulated UAV by using the listClients object function. The output contains only the simulated UAV, which shows that no other MAVLink client is connected to the simulated UAV.

listClients(uavClient)
ans=1×4 table
    SystemID    ComponentID       ComponentType             AutopilotType     
    ________    ___________    ____________________    _______________________

       1             1         "MAV_TYPE_QUADROTOR"    "MAV_AUTOPILOT_GENERIC"

Launch QGroundControl.

To establish a connection with QGroundControl, first create a blank heartbeat message by using the createmsg object function.

heartbeat = createmsg(dialect,"HEARTBEAT");

Assign the component type and autopilot type of the simulated UAV, and the system status, to the heartbeat message fields.

heartbeat.Payload.type(:) = enum2num(dialect,MAV_TYPE=uavClient.LocalClient.ComponentType);
heartbeat.Payload.autopilot(:) = enum2num(dialect,MAV_AUTOPILOT=uavClient.LocalClient.AutopilotType);
heartbeat.Payload.system_status(:) = enum2num(dialect,MAV_STATE="MAV_STATE_STANDBY");

Create a timer callback function. Configure the callback function to send the heartbeat message to QGroundControl through a UDP connection using the sendudpmsg object function.

localHost = "127.0.0.1";
qgcPort = 14550;
heartBeatTimerFunction = @(~,~)sendudpmsg(uavClient,heartbeat,localHost,qgcPort);

Create a timer object with a fixed rate execution mode, period of 1 second, and the timer callback function. 

heartbeatTimer = timer(ExecutionMode="fixedRate",Period=1,TimerFcn=heartBeatTimerFunction);

Start the timer object. The local simulated UAV broadcasts the heartbeat message at 1 Hz, and QGroundControl connects to the simulated UAV.

start(heartbeatTimer)

List the MAVLink clients again to verify that QGroundControl is now connected. The output shows that QGroundControl is a connected MAVLink client with a component type of MAV_TYPE_GCS.

listClients(uavClient)

Once you have finished running the example, stop and delete the timer object to end the connection.

stop(heartbeatTimer)
delete(heartbeatTimer)

Input Arguments

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MAVLink client connection, specified as a mavlinkio object.

Name-Value Arguments

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Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example: 'LocalPort',12345

Identifying connection name, specified as the comma-separated pair consisting of 'ConnectionName' and a string scalar. The default connection name is "Connection#".

Data Types: string

Local port for UDP connection, specified as a numeric scalar. A value of 0 binds to a random open port.

Data Types: double

Output Arguments

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Identifying connection name, specified as a string scalar. The default connection name is "Connection#", where # is an integer starting at 1 and increases with each new connection created.

Data Types: string

Version History

Introduced in R2019a

See Also

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