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Home Courses Hello (Real) World with ROS – Robot Operating System Course materials Lectures 1.1.2 ROS Nodes

1.1.2 ROS Nodes

Course subject(s) Module 1. ROS Essentials

In this lesson, we will find out what happens with ROS nodes. The focus of the video will be on three different ways to inspect ROS nodes and see what they’re doing.

Note:

In order to try the commands in this video,  you need to have the first ROS application running in a separate CCS.

You will build your own ROS application at a slightly later point this week!!

 

Remainder: Don’t forget to source your workspace if you want to use ROS commands!

If you’ve followed the procedure under the Course Setup section correctly, you only need to execute the following in the shell:
$ source $HOME/hrwros_ws/devel/setup.bash

Summary:

There are three main ways to inspect a ROS node:

  • Simply list all currently running nodes in the terminal:
    rosnode list
  • Make a visual graph of all running nodes and their connections:
    rqt_graph
  • List information about a specific node in the terminal:
    rosnode info <node_name>

In the following lectures, we will learn much more about Nodes. For example, we will see that they can publish (write) to a topic and subscribe (read) from a topic.

Creative Commons License
Hello (Real) World with ROS - Robot Operating System by TU Delft OpenCourseWare is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Based on a work at https://online-learning.tudelft.nl/courses/hello-real-world-with-ros-robot-operating-systems//.
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