Create a ROS package (C++)

Intro

Abstract

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

Workspace Setup

• Create ROS2 workspace

mkdir -p ~/ros2_ws/src  

• Initialize:

cd ~/ros2_ws && colcon build  

• Source environment

source install/setup.bash

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Create a Package

• Navigate to src:

cd ~/ros2_ws/src

• Create package:

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

• Folder 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  

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)
 
if(BUILD_TESTING)
  find_package(ament_lint_auto REQUIRED)
  # the following line skips the linter which checks for copyrights
  # comment the line when a copyright and license is added to all source files
  set(ament_cmake_copyright_FOUND TRUE)
  # the following line skips cpplint (only works in a git repo)
  # comment the line when this package is in a git repo and when
  # a copyright and license is added to all source files
  set(ament_cmake_cpplint_FOUND TRUE)
  ament_lint_auto_find_test_dependencies()
endif()
 
ament_package()
 

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Configure VS Code

• Configure VS Code to write inside a [C++] package

• Install any needed extensions

  • CMake extension
  • C/C++ Extension Pack: Popular extensions for C++ development in Visual Studio Code.

• See Fixing VS Code IntelliSense for ROS2 C++ Headers

---

Update CMakeLists.txt

• Add executable and link libraries:

add_executable(simple_publisher src/simple_publisher.cpp)
ament_target_dependencies(simple_publisher rclcpp std_msgs)
install(TARGETS simple_publisher DESTINATION lib/${PROJECT_NAME})

---

Build the Package

• Build workspace:

cd ~/ros2_ws && colcon build

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

Summary: 1 package finished [2.61s]

• Source install:

source install/setup.bash

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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