Category: Robot Operating System (ROS2)

There are three ways to to write a C++ publisher in ROS2, namely: Old-school approach Object-oriented (member-function) approach Local function (lambda) approach Below is an example of each approach to write a C++ node publishing “Hello World”. The code is taken from here: https://github.com/ros2/examples/tree/foxy/rclcpp/topics/minimal_publisher

Creating a C++ package Step 1: Create the package using the following CLI command: cd ~/ros2_ws/srcros2 pkg create [PACKAGE_NAME] –build-type ament_cmake –dependencies rclcpp std_msgs [OTHER_DEPENDENCY_PACKAGES] Step 2: Modify package.xml file for package dependencies of the created node(s). Step 3: Modify CMakeLists.txt.

ROS2 build system is colcon. In ROS1, the build system is catkin. What is the difference between ROS1 and ROS2 packages? In ROS1, you can mix C++ and Python nodes in a single package. In ROS2, as a standard practice, you either make a C++ package or a Python package. [Although as a non-standard practice, …

In ROS1, the structure of an overlay workspace, called the catkin workspace, looks like this: workspace_folder: |–src |–CMakeLists.txt |–package_1_folder |– |–package_n_folder |–devel |–build |–install The catkin workspace is built by running “catkin_make” command. To rebuild a catkin workspace, simply delete all the folders inside the workspace but the “src” folder and subsequently run the “catkin_make” …

The main tutorial page for ROS2 Foxy can be found here: https://docs.ros.org/en/foxy/index.html It is recommended to install a Long-Term Suppport (LTS) ROS2 distro. This tutorial describes the installation of ROS2 Foxy on Ubuntu 20. There are two ways to install ROS2: 1) from source and 2) from binary (Debian installer). Step 1: Make sure you …