ex01_first_package

ROS is short for Robot Operating System. It is a framework/middleware for the quick development of software related to robotics. It provides the infrastructure for sensor and actuator communications, sensor data handling, serialization, visualizations, and software packaging. All these things don’t change for different types of robots. Roboticists are happy

• to not implement everything from scratch for every robot they have,
• that they can use other software that was already implemented somewhere in the world.

ROS1 was invented in 2007. It was mostly used in research and is completely open-source. Some design choices were considered bad. In addition, it had no guarantees in real-time executions nor in how safe communications were. Recently ROS2 was released in 2017, seeking to overcome those and other issues.

With the following set of repositories, we try to explain the basic ROS concepts by example.

ROS2

To continue a computer with natively installed Ubuntu 22.04 is required. Come back if you find one.

Great to see you have found one. Now install ROS2 humble with the following steps (official instructions: https://docs.ros.org/en/humble/Installation/Ubuntu-Install-Debians.html)

Open a terminal:

Useful packages

sudo apt-get install vim

Preparation

locale  # check for UTF-8

sudo apt update && sudo apt install locales
sudo locale-gen en_US en_US.UTF-8
sudo update-locale LC_ALL=en_US.UTF-8 LANG=en_US.UTF-8
export LANG=en_US.UTF-8

locale  # verify settings

sudo apt install software-properties-common
sudo add-apt-repository universe

sudo apt update && sudo apt install curl -y
sudo curl -sSL https://raw.githubusercontent.com/ros/rosdistro/master/ros.key -o /usr/share/keyrings/ros-archive-keyring.gpg

echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/ros-archive-keyring.gpg] http://packages.ros.org/ros2/ubuntu $(. /etc/os-release && echo $UBUNTU_CODENAME) main" | sudo tee /etc/apt/sources.list.d/ros2.list > /dev/null

Refresh the package sources

sudo apt update

Upgrade all packages you already have

sudo apt upgrade

Installation

Now start the ROS2-humble installation:

sudo apt install ros-humble-desktop

Some additional dev tools:

sudo apt install ros-dev-tools

Environment Variables

In many situations, ROS2 will need additional configuration via setting environment variables. A good way is to add additional environment variables to the ~/.bashrc file (~ is the path to your home folder). Then they will be set every time a new terminal is started. Open the file with Vim (yes with vim) and add the following line to the end of the file:

vi ~/.bashrc

Try to insert this at the end of the file:

source /opt/ros/humble/setup.bash

Exit Vim: https://stackoverflow.com/questions/11828270/how-do-i-exit-vim. The sooner you learn Vim the better. As soon as you restart your terminal this command will set up everything you will need for your global ROS2. Test your installation via

ros2 run demo_nodes_cpp talker

open another terminal (Ctrl+Shift+T) and execute:

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