ROS 2 Talker and Listener Demo

Overview

This project demonstrates basic ROS 2 publisher-subscriber communication using a simple talker (publisher) and listener (subscriber) example.

Prerequisites

• ROS 2 installed and configured
• Working ROS 2 workspace (ros2_ws)
• MARIO repository cloned

Installation

1. Copy the package to your ROS 2 workspace:

   cp -r ~/MARIO/1_chatter_listener ~/ros2_ws/src
   

1. Navigate to your workspace:

   cd ~/ros2_ws
   

1. Build the package:

   colcon build
   

1. Source the workspace:

   source install/setup.bash
   

Running the Demo

Terminal 1 - Talker (Publisher)

source ~/ros2_ws/install/setup.bash
ros2 run chatter_listener talker.py

Terminal 2 - Listener (Subscriber)

source ~/ros2_ws/install/setup.bash
ros2 run chatter_listener listener.py

Demo Visualization

Additional Information

• The talker node publishes messages at a fixed rate
• The listener node subscribes to these messages and displays them
• Both nodes need to be run simultaneously to demonstrate the communication

Troubleshooting

• Ensure both terminals are properly sourced
• Check if ROS 2 daemon is running (ros2 daemon status)
• Verify that nodes are visible using ros2 node list