RobotnixAcademy

Unit 04 · overview

Unit 4 — Topics and Messages

Nodes are useful because they can exchange information.

Topics are ROS 2's publish/subscribe path for data that can continue to arrive over time.

PUBLISHER NODE
      ↓ publishes typed messages
    /topic
      ↓ delivers matching type
SUBSCRIBER NODE

Lessons

  1. Streaming Data: Why Topics Exist
  2. List Topics and Their Types
  3. Echo Live Messages
  4. Inspect Topic Endpoints
  5. Read Message Interfaces
  6. Publish From the Command Line
  7. Diagnose Topic Failures
  8. Unit Mission: Command Turtlesim With Evidence

Unit artifact

A publisher-topic-subscriber trace that proves which node publishes, which node subscribes, which message type is used, what the message structure contains, and what happens when you publish a valid command yourself.

Source attribution: adapted from the ROS 2 Jazzy topic tutorial in Gh0stlyKn1ght/ros2_documentation, CC BY 4.0.