Create a ROS package (C++) v2

Intro

Creating a package using CMake

How to create, build, and run a C++ ROS2 package with a minimal setup.

References

• The Robotics Back-End- Create a ROS2 Cpp Package
• https://docs.ros.org/en/jazzy/Tutorials/Beginner-Client-Libraries/Creating-Your-First-ROS2-Package.html

Setup

Workspace Setup

• Create ROS2 workspace

mkdir -p ros2_ws/src  

• Initialize:

cd ros2_ws && colcon build  

• Source environment

source install/setup.bash

Configure VS Code

• Configure VS Code to write inside a C++ package
• Install any needed extensions (VS Code C++ Configuration)

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Create a Package

• Navigate to src:

cd ~/ros2_ws/src

• Create a ROS2 package my_package

ros2 pkg create --build-type ament_cmake my_package --dependencies rclcpp std_msgs

This creates a ROS2 package skeleton, registers dependencies (rclcpp, std_msgs), sets up build system (ament_cmake), but does not create nodes or executables

Package Structure:

ROS2 CMake Packages

my_package/  
├── CMakeLists.txt      # Sets rules to build the package so you can run ros2 run... 
├── include/  
│   └── my_package/     # Directory containing the public headers for the package  
├── package.xml         # File containing meta-information about the package  
└── src/                # Directory containing the source code (AKA ROS nodes) for the package  

package.xml

<?xml version="1.0"?>
<?xml-model href="http://download.ros.org/schema/package_format3.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?>
<package format="3">
  <name>my_package</name>
  <version>0.0.0</version>
  <description>TODO: Package description</description>
  <maintainer email="">email</maintainer>
  <license>TODO: License declaration</license>
 
  <buildtool_depend>ament_cmake</buildtool_depend>
 
  <depend>rclcpp</depend>
  <depend>std_msgs</depend>
 
  <test_depend>ament_lint_auto</test_depend>
  <test_depend>ament_lint_common</test_depend>
 
  <export>
    <build_type>ament_cmake</build_type>
  </export>
</package>

CmakeLists.txt

cmake_minimum_required(VERSION 3.8)
project(my_package)
 
if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
  add_compile_options(-Wall -Wextra -Wpedantic)
endif()
 
# find dependencies
find_package(ament_cmake REQUIRED)
find_package(rclcpp REQUIRED)
find_package(std_msgs REQUIRED)
 
ament_package()

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Build the Package

• Build workspace:

cd ~/ros2_ws && colcon build

Example

Starting >>> my_package
Finished <<< my_package [2.41s]                  

Summary: 1 package finished [2.61s]

• Source install:

source install/setup.bash

Next: Build a node inside a ROS2 C++ package

• To actually add a node to a package, see Create a Minimal ROS Node (C++)

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