Software installation with ROS2

In this tutorial, we will learn how to install ROS2 Rolling Ridley on Ubuntu 22.04 and build our software stack.

0. Use Ubuntu 22.04

As ROS works best on Ubuntu, we are using this distribution. Currently, ROS2 Rolling runs on Ubuntu 22.04. If you are not already using Ubuntu 22.04, consider installing it on your system (perhaps as a dual boot), alternately you can run it in a virtual machine (not recommended, as recently we had some issues with it; https://www.virtualbox.org/) or use the ROS2 docker (https://github.com/timonegk/rosdocked)

1. Setup and Install ROS 2

• Follow this guide and when it comes to the section Install ROS 2 packages, install the recommended ros-rolling-desktop: https://docs.ros.org/en/rolling/Installation/Ubuntu-Install-Debians.html

• Follow the instructions on https://packages.bit-bots.de/

• Install additional dependencies:

sudo apt install \
python3-colcon-clean \
python3-colcon-common-extensions \
python3-pip \
python3-rosdep \
ros-rolling-plotjuggler-ros \
ros-rolling-rmw-cyclonedds-cpp \
ros-rolling-rqt-robot-monitor \
ros-rolling-rqt-runtime-monitor

2. Install Webots

• Navigate to https://github.com/cyberbotics/webots/releases and download the .deb file of Webots2022b.

• Install it using the command sudo apt install ~/Downloads/webots_2022b_amd64.deb or similar, depending on your system setup.

3. Download our software

• Create a GitHub and Mafiasi account, if not already done (see here for further information on this: http://doku.bit-bots.de/private/manual/dienste_accounts.html) Those services host our Git software repositories.

• Add your SSH key to GitHub and Gitea to access and sync our repositories

  • If you don’t know what I am talking about or you don’t yet have a SSH key, follow this guide: https://docs.github.com/en/authentication/connecting-to-github-with-ssh/checking-for-existing-ssh-keys

  • Go to your account settings and add your SSH key (the .pub file) for GitHub AND Gitea

• Now, you can clone (download) our main code repository (repo) called bitbots_meta:

  • Open a terminal and go to the directory where you want to download our code (typically ~/git/bitbots/)

    • Create the directory with: mkdir -p ~/git/bitbots This is were your source code will live and grow.

    • Move to this directory with: cd ~/git/bitbots

  • Clone the code repository with: git clone git@github.com:bit-bots/bitbots_meta.git Confirm the host key by typing yes, if asked.

  • Move into the newly created directory with: cd bitbots_meta

  • Clone all sub-repositories and other files by running: make pull-init

• If you want to run the robot’s cameras on your system, also run the following command: make basler Confirm the host key by typing yes, if asked.

4. Install additional dependencies

We need to install the requirements of our software. Most of these can be automatically installed with rosdep. In the bitbots_meta folder, simply run sudo rosdep init followed by rosdep update and rosdep install --rosdistro=rolling --from-paths . --ignore-src -y.

We also need to install some python packages using pip, the python package manager.

• Upgrade python package manager: pip3 install pip -U

• Optionally if you want you can setup a local venv with: python -m venv venv-bitbots && source venv-bitbots/bin/activate HINT: the sourcing of the venv is required in every newly opened terminal!

• Install required python packages: pip3 install --user -r requirements.txt

5. Setup colcon workspace

Colcon is the tool provided by ROS 2 to build and install our ROS packages, so that they can be launched later. The colcon workspace is where your source code gets build and where we use colcon.

• Create colcon workspace directory (typically ~/colcon_ws/)

  • Create directory with: mkdir -p ~/colcon_ws/src

  • Link our software contained in the bitbots_meta repo to the newly created src directory with: ln -s ~/git/bitbots/bitbots_meta/ ~/colcon_ws/src/bitbots_meta

6. Final touches

To let your system know where it should find all the ROS 2 dependencies and packages and to add colored output etc., we add a little bit of config to your ~/.bashrc file, which will be run every time you open a new terminal. In case you are not using the bash shell, replace ~/.bashrc and bash with your shell’s configuration file.

• Run the following command:

cat >> ~/.bashrc << EOF
export PATH=\$PATH:\$HOME/.local/bin
export COLCON_WS="\$HOME/colcon_ws"
export COLCON_LOG_LEVEL=30
export RCUTILS_COLORIZED_OUTPUT=1
export RCUTILS_CONSOLE_OUTPUT_FORMAT="[{severity}] [{name}]: {message} ({function_name}() at {file_name}:{line_number})"
export RMW_IMPLEMENTATION=rmw_cyclonedds_cpp
source /opt/ros/rolling/setup.bash
eval "\$(register-python-argcomplete3 ros2)"
eval "\$(register-python-argcomplete3 colcon)"
EOF

• Optionally, run the following command to set some useful shortcuts for various ROS2 commands:

cat >> ~/.bashrc << EOF
alias rr='ros2 run'
alias rl='ros2 launch'

alias rte='ros2 topic echo'
alias rtl='ros2 topic list'
alias rth='ros2 topic hz'
alias rtp='ros2 topic pub'

alias rpl='ros2 param list'
alias rpg='ros2 param get'

alias cdc='cd \$COLCON_WS'

alias cba='cdc && colcon build --symlink-install --continue-on-error'
alias cbn='cdc && colcon build --symlink-install --continue-on-error --packages-select'
alias cb='cdc && colcon build --symlink-install --continue-on-error --packages-up-to'
alias cc='cdc && colcon clean packages --packages-select'
alias cca='cdc && colcon clean packages'

alias sr='source /opt/ros/rolling/setup.bash'
alias sc='source \$COLCON_WS/install/setup.bash'
alias sa='sr && sc'
EOF