ROS melodic on Raspbian Buster

This tutorial is to install ROS melodic on latest (Mon 2020) version of Raspbian.

Hardware

The hardware I use is Raspberry Pi 4

Install Raspbian Buster

Download the latest Raspbian Buster image from the official website and follow the Installation Guide to flash the image into a SD card.

For Windows users, I would recommend using Etcher to do such work. It’s really easy to use and reliable. (I usually use my Windows laptop to flash a SD card, so I don’t know what’s the best approach on other system. Please refer to the official guide and follow the steps carefully).

Headless installation

(Ref Setting up a Raspberry Pi headless)

If you do not have a computer screen for your Pi, you need to setup the wifi beforehand.

Firstly, plug back your SD card reader with the SD card you just flashed to your laptop.

In Windows, you’ll see a disk named “boot” in the navigator of File Explorer. (You’ll also see a popup window saying that you need to format a disk. Be careful NOT to format it, otherwise you’ll need to flash again)

Create a txt file with filename “wpa_supplicant.conf”.

Use some advanced text editor (eg: Visual Studio Code) to open the file, change the EoF sequence from CRLF to LF and insert following content (replace ssid and psk with your wireless network setup)

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=US

network={
 ssid="&ltName of your WiFi&gt"
 psk="&ltPassword for your WiFi&gt"
}

Create a blank txt file with filename “ssh” (no extention)

Eject the SD card from laptop and boot your Pi using modified SD card.

If your setup is correct, you can find your Pi in the local network. (Using IP scanner or whatever you used to find your Pi usually)

Upgrade system and install common software

Run following commands

sudo apt update && sudo apt -y dist-upgrade && sudo apt -y upgrade
sudo apt install -y vim curl wget git tmux unzip

Reboot your Pi after installation

sudo reboot

Install ROS melodic

(Ref Installing ROS Kinetic on the Raspberry Pi, please note that the link is for ROS Kinetic)

Setup ROS Repository

sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" &gt /etc/apt/sources.list.d/ros-latest.list'
sudo apt-key adv --keyserver hkp://ha.pool.sks-keyservers.net:80 --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654
sudo apt-get update && sudo apt-get -y upgrade

Install dependencies

sudo apt-get install -y python-rosdep python-rosinstall-generator python-wstool python-rosinstall build-essential cmake

Initialize rosdep

sudo rosdep init
rosdep update

Compile ROS melodic from source code

If you want to try the pre-build install, skip this and go to next section.

Create catkin workspace for compiling and installing ROS melodic

mkdir -p ~/ros_catkin_ws
cd ~/ros_catkin_ws

Fetch source code by wstool

rosinstall_generator ros_comm --rosdistro melodic --deps --wet-only --tar &gt melodic-ros_comm-wet.rosinstall
wstool init src melodic-ros_comm-wet.rosinstall

NOTE
The above is fetching “ros_comm” package which includes basic ROS commnication libs without GUI tools such as rqt, rviz. If you want to install GUI tools, change “ros_comm” to “desktop”. Or you can find more ROS variant here

NOTE
If wstool init got interrupted, you can resume downloading process by wstool update -j4 -t src

Resolve dependencies with rosdep

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

Build and install ROS!

sudo ./src/catkin/bin/catkin_make_isolated --install -DCMAKE_BUILD_TYPE=Release --install-space /opt/ros/melodic

Add ROS to your bashrc​

echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc

Pre-build workspace

If you already proceed through last section, skip this.

Download pre-build worksapce and unzip it

ros_melodic_raspbian_buster.zip

Upload to your RPi and place in home directory.

Unzip it

cd ~
unzip ros_melodic_raspbian_buster.zip

After that, you’ll get a folder called ros_catkin_ws

Resolve dependencies with rosdep

cd ~/ros_catkin_ws
rosdep install -y --from-paths src --ignore-src --rosdistro melodic -r --os=debian:buster

Install ROS

sudo ./src/catkin/bin/catkin_make_isolated --install -DCMAKE_BUILD_TYPE=Release --install-space /opt/ros/melodic

Add ROS to your bashrc​

echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc

About ROS package management on Raspbian

If you use Ubuntu, apt is used to manage ROS packages. However, this approach does not works on RPi currently. We need to build from the source code of the package you want to install.

The process to add new package is as follow

Generate rosinstall file with rosinstall_generator

You may see similar command above somewhere during the installation. This is to generate a list of package source link.

cd ~/ros_catkin_ws
rosinstall_generator &ltpackage names seperated by space&gt --rosdistro melodic --deps --wet-only --tar &gt &ltcustom file name&gt.rosinstall

Example (to install sensor_msgs)

rosinstall_generator sensor_msgs --rosdistro melodic --deps --wet-only --tar &gt melodic-sensor_msgs.rosinstall

Merge and update the workspace

wstool merge -t src &ltrosinstall file you just generated&gt.rosinstall
wstool update -t src

This will fetch all the source code listed in rosinstall files

Example

wstool merge -t src melodic-sensor_msgs.rosinstall
wstool update -t src

Resolve dependency by rosdep

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

Rebuild the workspace

sudo ./src/catkin/bin/catkin_make_isolated --install -DCMAKE_BUILD_TYPE=Release --install-space /opt/ros/melodic

Conclusion

It’s a bit tedious installing ROS and managing pakcage on RPi and the build time is long. So I wrote this post for memo and future reference.

Next post I’ll talk about how to setup the multi-machine environment and then create a publisher node on RPi.

Link to other relavant post

• ROS melodic on Raspbian Buster (this post)
• Multiple machine setup for ROS melodic
• Create ROS publisher node using rospy on Raspberry Pi