You're reading from ROS 2 from Scratch Get started with ROS 2 and create robotics applications with Python and C++

Product type Paperback

Published in Nov 2024

Publisher Packt

ISBN-13 9781835881408

Length 380 pages

Edition 1st Edition

Concepts

Robotics

Author (1):

Edouard Renard

View More author details

Table of Contents (20) Chapters

Preface

1. Part 1:Getting Started with ROS 2

2. Chapter 1: Introduction to ROS 2 – What Is ROS 2? FREE CHAPTER

3. Chapter 2: Installing and Setting Up ROS 2

4. Chapter 3: Uncovering ROS 2 Core Concepts

5. Part 2: Developing with ROS 2 – Python and C++

6. Chapter 4: Writing and Building a ROS 2 Node

7. Chapter 5: Topics – Sending and Receiving Messages between Nodes

8. Chapter 6: Services – Client/Server Interaction between Nodes

9. Chapter 7: Actions – When Services Are Not Enough

10. Chapter 8: Parameters – Making Nodes More Dynamic

11. Chapter 9: Launch Files – Starting All Your Nodes at Once

12. Part 3: Creating and Simulating a Custom Robot with ROS 2

13. Chapter 10: Discovering TFs with RViz

14. Chapter 11: Creating a URDF for a Robot

15. Chapter 12: Publishing TFs and Packaging the URDF

16. Chapter 13: Simulating a Robot in Gazebo

17. Chapter 14: Going Further – What To Do Next

18. Index

Why subscribe?

19. Other Books You May Enjoy

Launch files

Let’s finish this list of ROS 2 concepts with launch files.

A launch file will allow you to start several nodes and parameters from just one file, which means that you can start your entire application with just one command line.

In Chapter 9, you will learn how to write your own launch file, but for now, let’s just start a few to see what they do.

Starting a launch file

To start a single node in the terminal, you have seen the ros2 run command. For launch files, we will use ros2 launch <package_name> <launch_file>.

Stop all running nodes, and let’s start the talker_listener launch file from the demo_nodes_cpp package. In Terminal 1, run the following command:

$ ros2 launch demo_nodes_cpp talker_listener_launch.py
[INFO] [launch]: All log files can be found below /home/ed/.ros/log/2024-03-14-16-09-27-384050-ed-vm-2867
[INFO] [launch]: Default logging verbosity is set to INFO
[INFO] [talker-1]: process started with pid...