Node_Program.md

ROS2 Program

Creating a Package

cd ~/ros2_ws/src/
ros2 pkg create <package_name> --build-type ament_python --dependencies rclpy

Creating a Node

cd ~/ros2_ws/src/packagename/packagename/
touch <Node_Name.py>
chmod +x <Node_Name.py>

Writing code

Open Terminal and move to the directory

cd ~/ros2_ws/src/
code .

It will open the vs code and you have to write the code in the vs code for your nodes and you have to write the code in the created Python Node file like this

#!/usr/bin/env python3
import rclpy
from rclpy.node import Node
class MyCustomNode(Node):
    def __init__(self):
        super().__init__('my_node_name')
        self.get_logger().info("Hello World") #This Line will print the Info
def main(args=None):
    rclpy.init(args=args)
    node = MyCustomNode()
    rclpy.spin(node)
    rclpy.shutdown()
if __name__ == '__main__':
    main()

Then get to the setup.py file in the same package and if you scroll down you can able to see entry_points script there type this entry_points={ 'console_scripts': [ "test_node = my_py_pkg.my_first_node:main" #Syntax is <executable_name> = <package_name>.<node_name>:<function_name> ], },

After this we need to build the package

cd ~/ros2_ws/
colcon build

Running Node

source ~/.bashrc
ros2 run my_py_pkg test_node