ROS2 Series

About this Blog

In the Previous Blog, we learnt how to Install Ubuntu 22.04 via WSL and Setup ROS2 (Humble) Distro inside the Ubuntu 22.04, now - in this blog we will learn:

Creating a New Workspace in ROS2 Humble
Creating a New Package in the Workspace
Adding, Editing and Running the Node File created inside the Package
A Simple and Basic ROS2 Project as an Example

Opening Ubuntu-22.04 via WSL

Okay, so first things first - we will open our Ubuntu-22.04 via WSL in the Windows Powershell

Open Command-Prompt/Terminal and Run the following Command -
```
PS C:\Users\aayus> wsl -d Ubuntu-22.04
```
this command will tell WSL to boot-up/open the previously installed Ubuntu-22.04 in your PC and after this you'll see an output somewhat like this -
```
root@DESKTOP-D3IK1O1:/mnt/c/Users/aayus#
```

Creating a New Workspace in Ubuntu-22.04 for ROS2

Now we will create a New Workspace step-by-step in our Ubuntu-22.04, follow the below lines of code and type it all in the mentioned order -

Make New Directory (with src folder inside) -
```
mkdir -p ~/sample_ws/src
```
Change Directory -
```
cd ~/sample_ws
```
Initialize and Build the Worskpace -
```
colcon build
```
Source the Workspace (for ROS2 to find your packages) -
```
source install/setup.bash
```

Creating a New Package inside the Workspace for ROS2 (Ament-Type: Python)

After creating a new workspace, we will move on and create a New Package inside the workspace that we created just above this section - the package will be built in Python (you can also build your package in C++)

Change Directory (back to src)
```
cd ~/sample_ws/src
```

Create a New Package (in the sample_ws/src/)

ros2 pkg create --build-type ament_python your_pkg_name

you should see an output somewhat like this -

going to create a new package
package name: your_pkg_name
destination directory: /root/sample_ws/src
package format: 3
version: 0.0.0
description: TODO: Package description
maintainer: ['root <root@todo.todo>']
licenses: ['TODO: License declaration']
build type: ament_python
dependencies: []
creating folder ./your_pkg_name
creating ./your_pkg_name/package.xml
creating source folder
creating folder ./your_pkg_name/your_pkg_name
creating ./your_pkg_name/setup.py
creating ./your_pkg_name/setup.cfg
creating folder ./your_pkg_name/resource
creating ./your_pkg_name/resource/your_pkg_name
creating ./your_pkg_name/your_pkg_name/__init__.py
creating folder ./your_pkg_name/test
creating ./your_pkg_name/test/test_copyright.py
creating ./your_pkg_name/test/test_flake8.py
creating ./your_pkg_name/test/test_pep257.py
[WARNING]: Unknown license 'TODO: License declaration'.  This has been set in the package.xml, but no LICENSE file has been created.
It is recommended to use one of the ament license identitifers:
Apache-2.0
BSL-1.0
BSD-2.0
BSD-2-Clause
BSD-3-Clause
GPL-3.0-only
LGPL-3.0-only
MIT
MIT-0

you can ignore the warnings here, as it's just related to declaration of standard license file inside your package

Creating a New Node File inside the Package for ROS2 (File-Type: Python)

So far we have created a New Workspace and a New Package inside the Workspace. Now we'll begin the real work, and that is creating a New Node-File inside our Package (so that we can do some cool shit within ROS2).

Change Directory (move into the package - sample_ws/src/your_pkg_name)
```
cd ~/sample_ws/src/your_pkg_name/your_pkg_name
```
Create a New File (and Make it Executable)
```
touch example.py 
chmod +x example.py
```

Editing the newly created File

nano example.py

after typing this line you'll see a new empty screen pop-up, don't worry that is the node-file which we created before, and now we have to just add our code in this node-file.
copy paste the following code in your empty node-file (example.py) -

#!/usr/bin/env python3

import rclpy
from rclpy.node import Node
class MyNode(Node):
    def __init__(self):
    super().__init__('example')
    self.create_timer(0.2, self.timer_callback)

def timer_callback(self):
    self.get_logger().info("[Enter_Your_Name] is learning ROS!")

def main(args=None):
    rclpy.init(args=args)
    node = MyNode()
    rclpy.spin(node)
    rclpy.shutdown()

if __name__ == '__main__':
    main()

After copy-pasting the above code, we will have to exit the example.py node-file and to do that - just press the below keys in your PC: Ctrl + O ---> Enter ---> Ctrl + X

Editing the Package Setup Configs

We will edit the Package Configurations by editing the setup.py file which is present in our Package

Edit the Package Setup Configs (Opening the setup.py file to Edit)

cd ~/sample_ws/src/your_pkg_name
nano setup.py

after typing the above line of code, we'll again get a new pop-up screen with the following code (written in python) -

from setuptools import find_packages, setup
package_name = 'your_pkg_name'
setup(
    name=package_name,
    version='0.0.0',
    packages=find_packages(exclude=['test']),
    data_files=[
        ('share/ament_index/resource_index/packages',
        ['resource/' + package_name]),
        ('share/' + package_name, ['package.xml']),
    ],
    install_requires=['setuptools'],
    zip_safe=True,
    maintainer='root',
    maintainer_email='root@todo.todo',
    description='TODO: Package description',
    license='TODO: License declaration',
    tests_require=['pytest'],
    entry_points={
        'console_scripts': [
        ],
    },
)

this is the actual setup.py file in which we have to edit and add the following line of code -

entry_points={
    'console_scripts': [
    'example=your_pkg_name.example:main', #add this line in your 'setup.py' code
    ]
}

After copy-pasting and making the necessary changes in the above code, we will have to exit the setup.py file and to do that - just press the below keys in your PC: Ctrl + O ---> Enter ---> Ctrl + X

Running the Node-File in ROS2 Environment

After you've made the new node file and added all the code and edited the changes in it, we'll run the example.py node-file in the ROS2 Environment

Build and Source the Workspace Again

cd ~/sample_ws
colcon build
source install/setup.bash

Run the Node-File from your Package

ros2 run your_pkg_name example

after finally typing the above line of code, you'll see your output which looks somewhat like this -

[INFO] [1756233189.439256087] [example]: [Enter_Your_Name] is learning ROS!
[INFO] [1756233189.624581082] [example]: [Enter_Your_Name] is learning ROS!
[INFO] [1756233189.824239942] [example]: [Enter_Your_Name] is learning ROS!
[INFO] [1756233190.023546492] [example]: [Enter_Your_Name] is learning ROS!
.... this keeps on continuously printing the same output

to stop the continuous printing of the output statement, just do Ctrl + C and it'll stop.

Congratulations! You've Completed All the Content of this Blog. Now you can, Create a Workspace and a Package within that Workspace and also Create a Node-File within that Package. And run the Node-File to get the expected output.

Thank You for Reading this Blog! Written by Aayush A. Mishra - August, 2025

ROS2 Series