mavlinkio

Connect with MAVLink clients to exchange messages

Description

The mavlinkio object connects with MAVLink clients through UDP ports to exchange messages with UAVs (unmanned aerial vehicles) using the MAVLink communication protocols.

Creation

Syntax

mavlink = mavlinkio(msgDefinitions)

mavlink = mavlinkio(dialectXML)

mavlink = mavlinkio(dialectXML,version)

mavlink = mavlinkio(___,Name,Value)

Description

mavlink = mavlinkio(msgDefinitions) creates an interface to connect with MAVLink clients using the input mavlinkdialect object, which defines the message definitions. This dialect object is set directly to the Dialect property.

mavlink = mavlinkio(dialectXML) directly specifies the XML file for the message definitions as a file name. A mavlinkdialect is created using this XML file and set to the Dialect property

mavlink = mavlinkio(dialectXML,version) additionally specifies the MAVLink protocol version as either 1 or 2.

mavlink = mavlinkio(___,Name,Value) additionally specifies arguments using the following name-value pairs.

Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name must appear inside quotes. You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.

The name-value pairs directly set the MAVLink client information in the LocalClient property. See LocalClient for more info on what values can be set.

Properties

Dialect — MAVLink dialect

mavlinkdialect object

MAVLink dialect, specified as a mavlinkdialect object. The dialect specifies the message structure for the MAVLink protocol.

LocalClient — Local client information

structure

This property is read-only.

Local client information, specified as a structure. The local client is setup in MATLAB^® to communicate with other MAVLink clients. The structure contains the following fields:

• SystemID

• ComponentID

• ComponentType

• AutopilotType

To set these values when creating the mavlinkio object, use name-value pairs. For example:

mavlink = mavlinkio("common.xml","SystemID",1,"ComponentID",1)

This property is nontunable when you are connected to a MAVLink client. For more information, see mavlinkclient.

Data Types: struct

Object Functions

connect	Connect to MAVLink clients through UDP port
disconnect	Disconnect from MAVLink clients
sendmsg	Send MAVLink message
sendudpmsg	Send MAVLink message to UDP port
serializemsg	Serialize MAVLink message to binary buffer
listConnections	List all active MAVLink connections
listClients	List all connected MAVLink clients
listTopics	List all topics received by MAVLink client

Examples

Store MAVLink Client Information

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)

Work with MAVLink Connection

This example shows how to connect to MAVLink clients, inspect the list of topics, connections, and clients, and send messages through UDP ports using the MAVLink communication protocol.

NOTE: This example requires you to install the UAV Library for Robotics System Toolbox®. Call roboticsAddons to open the Add-ons Explorer and install the library.

Connect to a MAVLink client using the "common.xml" dialect. This local client communicates with any other clients through a UDP port.

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

ans = 
"Connection1"

You can list all the active clients, connections, and topics for the MAVLink connection. Currently, there is only one client connection and no topics have received messages.

listClients(mavlink)

ans=1×4 table
    SystemID    ComponentID    ComponentType          AutopilotType     
    ________    ___________    ______________    _______________________

      255            1         "MAV_TYPE_GCS"    "MAV_AUTOPILOT_INVALID"

listConnections(mavlink)

ans=1×2 table
    ConnectionName      ConnectionInfo   
    ______________    ___________________

    "Connection1"     "UDP@0.0.0.0:44099"

listTopics(mavlink)

ans =

  0x5 empty table

Create a subscriber for receiving messages on the client. This subscriber listens for the "HEARTBEAT" message topic with ID equal to 0.

sub = mavlinksub(mavlink,0);

Create a "HEARTBEAT" message using the mavlinkdialect object. Specify payload information and send the message over the MAVLink client.

msg = createmsg(dialect,"HEARTBEAT");
msg.Payload.type(:) = enum2num(dialect,'MAV_TYPE','MAV_TYPE_QUADROTOR');
sendmsg(mavlink,msg)

Disconnect from the client.

disconnect(mavlink)