Getting Started ROS2

We will proceed with Humble ROS release (opens in a new tab) as it is the most stable and recent LTS. This page explains the installation.

In summary:

• Option 1: For the best learning and development experience, it is highly recommended to install Ubuntu 22.04. Ubuntu 20.04 is also okay. But you might have difficulties during the last part of this tutorial.
• Option 2: If you need to learn ROS on Windows, opt for WSL (Windows Subsystem for Linux) and install Ubuntu version instead of the Windows native version (opens in a new tab).
• Option 3: For those who don't have either of the above options, I have created a Docker image.

Installation options

Option 1: Ubuntu 22.04 (best case)

If you can use Ubuntu 22.04, it caters Humble ROS release (opens in a new tab) in its source list. You can install ROS locally. All you need is just to follow the instructions (opens in a new tab) by copy-and-paste. Install full desktop packages by sudo apt install ros-humble-desktop. It can take a couple of minutes.

For Ubuntu 20.04 users

You cannot install locally Humble version in this case. Instead, you have to use the earlier version Foxy. Although as of now July 2023, choosing Humble your target distribution is the best option, Foxy is enough for learning the basics of ROS2. Visit here (opens in a new tab) and follow the instructions one by one.

Option 2: WSL2 (Windows users)

To learn ROS2 on a Windows machine, setting up a Linux environment can significantly enhance the learning experience, rather than following Windows native installation of ROS. One efficient way to achieve this is by utilizing Windows Subsystem for Linux (WSL2).

Bring Ubuntu to Windows

Firstly, you need to install WSL2 (opens in a new tab) on your Windows system to have a virtual environment for Ubuntu 22.04.

Follow the steps in this video tutorial (opens in a new tab) to get WSL2 up and running. After opening ubuntu terminal, please make sure lsb_release -a outputs 22.04 version.

user_name@user:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 22.04.2 LTS
Release:        22.04
Codename:       jammy

If your default Ubuntu distribution is not 22.04 (e.g., 20.04), visit the Microsoft Store and install Ubuntu 22.04 (opens in a new tab) instead.

Enable GUIs (Only for Windows 10 Users)

If you are a Windows 11 user, you can access the GUIs running on Ubuntu terminal, out-of-box. Run xmessage --center hello and a small window will popup. However, if you are running Ubuntu on WSL 2 of Windows 10, you have to do additional setup. Follow the tutorial video (opens in a new tab) for this process:

Same Process with Ubuntu on WSL

Now you can use Ubuntu on Windows. Overall, the remainder is the same as what this page explains.

Option 3. Docker

1. First of all, if you have not installed docker, follow the installation guide here (opens in a new tab). Windows users can install Docker by following this link (opens in a new tab).
2. Pull the prepared image (opens in a new tab) by

   docker pull bfjeon/ros2-humble
   This image is Ubuntu 22.04 and contained basic features like bash-completion to resemble a clean Ubuntu installation as best as possible.

Starting a Simple ROS program

We run a demo program in the package turtlesim (opens in a new tab). During part1, this package will help us to understand the basics of ROS2.

To be checked

Installation directory /opt/ros/humble

The installations of core and shipped packages are installed in /opt/ros/humble (if you installed foxy, /opt/ros/foxy). later if you want to remove ROS2, delete the directory.

Sourcing setup.bash

To utilize the convenient commands provided by ROS in terminals, we need to configure the opened terminal to recognize the set of ROS commands by sourcing the file /opt/ros/humble/setup.bash into your terminal. Open ~/.bashrc and make sure the line source /opt/ros/humble/setup.bash is written.

if ! shopt -oq posix; then
  if [ -f /usr/share/bash-completion/bash_completion ]; then
    . /usr/share/bash-completion/bash_completion
  elif [ -f /etc/bash_completion ]; then
    . /etc/bash_completion
  fi
fi
 
source /opt/ros/humble/setup.bash

After completing these steps, you will be able to utilize tab-completion. When you type ros2 and press the tab button on a terminal, the following options will appear:

rosmarry@rosmarry:~$ ros2 // press tab will show the belows:
--use-python-default-buffering  doctor                          lifecycle                       run
action                          extension_points                multicast                       security
bag                             extensions                      node                            service
component                       interface                       param                           topic
daemon                          launch                          pkg                             wtf

Install demo package if not installed

Run sudo apt-get install ros-humble-turtlesim in case it's not installed.

Run demo program turtlesim_node

Open a terminal (calling Terming A) and run the command:

ros2 run turtlesim turtlesim_node

This will open a GUI window. In the center, you will find a turtle.

In another terminal (Terminal B)

ros2 run turtlesim turtle_teleop_key

And in Terminal B, try pressing arrow-keys to move the turtle.

What's next?

Congratulation 👍 You're all set. From the next page, we will have a fun while learning the fundamentals of ROS with the adorable turtle and your terminal.