listTopics

List all topics received by MAVLink client

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Syntax

topicTable = listTopics(mavlink)

Description

topicTable = listTopics(mavlink) returns a table of topics received on the connected mavlinkio client with information on the message frequency.

example

Examples

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Open Live Script

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.

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@0.0.0.0:46583"


listTopics(mavlink)
ans =

  0×5 empty table

    MessageID    MessageName    SystemID    ComponentID    MessageFrequency
    _________    ___________    ________    ___________    ________________

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)

Input Arguments

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MAVLink client connection, specified as a mavlinkio object.

Output Arguments

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Topic info, returned as a table with SystemID, ComponentID, MessageID, MessageName, and MessageFrequency fields for each topic receiving messages on the client.

Version History

Introduced in R2019a

See Also

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External Websites