19.2.5. ROS Installation

In general you can follow the official instruction in the ROS wiki to install ROS under Raspbian Buster on the Raspberry Pi. But the following instructions will use catkin tools instead of catkin_make or catkin_make_isolated.

Note

If you use the 64bit Raspbian, you can follow the Debian standard installation guide and skip everything regarding ros_catkin_ws.

Workspace Concept

Since ROS is not availabe as binary packages for Raspbian, all the ROS packages have to be installed from source. To not flood our normal Catkin workspace, we create two seperate workspaces.

~/ros_catkin_ws

This is the workspace, where the source code of the packages we just want to install lives. We will configure Catkin to install these packages in /opt/ros/melodic. This is the directory, where the installation via prebuilt packages would also create its files. It is not very likely you get in touch with this workspace often after the initial installation.

~/catkin_ws

Your normal workspace directory. All the Hippocampus specific packages should be in here. Also other packages that you want to modify should be in this workspace.

Preparations

  1. Adding keys

    sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'

    curl -s https://raw.githubusercontent.com/ros/rosdistro/master/ros.asc | sudo apt-key add -

  2. Update source lists

    sudo apt update

  3. Install dependencies

    sudo apt install -y python3-rosdep python3-rosinstall-generator python3-vcstool python3-rosinstall build-essential cmake python3-catkin-tools

  4. Initialize rosdep

    sudo rosdep init

    rosdep update

Setup Workspace

  1. Create workspace

    mkdir -p ~/ros_catkin_ws/src && cd ~/ros_catkin_ws

  2. Fetch source code

    Attention

    The following commands will fetch the sources for the ros_comm meta package and the perception meta package. If you do not need all of them or if you need even more packages feel free to modify the following commands accordingly. Building unnecessary packages might be a waste of time.

    rosinstall_generator ros_comm perception --rosdistro noetic --deps --wet-only --tar > noetic-ros_comm-perception-wet.rosinstall

    vcs import --input noetic-ros_comm-perception-wet.rosinstall ./src

  3. Resolve dependencies

    rosdep install -y --from-paths src --ignore-src --rosdistro noetic -r --os=debian:buster

Build the Code

  1. Set the install space

    catkin config --install-space /opt/ros/noetic

  2. Use the install configuration instead of devel

    catkin config --install

  3. Start the build process

    Note

    Depending on your package configuration the next command may take some time, i.e. a few hours if you want to build many packages.

    sudo catkin build --cmake-args -DCMAKE_BUILD_TYPE=Release -DPYTHON_EXECUTABLE=/usr/bin/python3

Initialize User Workspace

  1. Source your ROS installation

    source /opt/ros/noetic/setup.zsh

  2. Create workspace

    mkdir -p ~/catkin_ws/src && cd ~/catkin_ws

  3. Initialize workspace

    catkin init

  4. Build empty workspace

    catkin build

This command created the devel directory inside your catkin workspace. To source your workspace you can either source it manually for each terminal session by executing source ~/catkin_ws/devel/setup.bash. A better way to handle this automatically is to append this command to your .bashrc file.

echo 'source $HOME/catkin_ws/devel/setup.zsh' >> ~/.zshrc

For this change of the .bashrc to take effect immediately execute:

source ~/.zshrc

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