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Nodes and Topics

Understanding Nodes​

A Node is a single process that performs a computation. Nodes communicate with each other using Topics, Services, and Actions.

The Publisher (Talker)​

We will create a simple "Talker" node that publishes a text message every second.

Code​

See src/ros2_foundations/ros2_foundations/talker.py.

The Subscriber (Listener)​

We will create a "Listener" node that subscribes to the topic and prints the message.

Code​

See src/ros2_foundations/ros2_foundations/listener.py.

Running the Example​

  1. Build the package:

    cd ~/ros2_ws
    colcon build --symlink-install
    source install/setup.bash

  2. Run Talker:

    ros2 run ros2_foundations talker

  3. Run Listener:

    ros2 run ros2_foundations listener