This guide explains how to install ROS 2 Dashing in Raspberry Pi 3b from Ubuntu repositories via apt install. This tutorial is based in the following link: https://medium.com/realroboox/how-to-setup-ros2-on-raspberry-pi-3-model-b-6b77cd350b7a.

First, is necessary to download Ubuntu 18.04.3 for arm64(aarch64) from official site http://cdimage.ubuntu.com/releases/bionic/release/ubuntu-18.04.3-preinstalled-server-arm64+raspi3.img.xz. Is really important to use this image, because, there are alternative versions with same name and its performance in raspberry could be compromised. Also, has some issues at ROS 2 installation. But, this version has fixed all this issues.

Setup 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

Install some dependencies

sudo apt update 
 
sudo apt install curl gnupg2 lsb-releasecurl -s https://raw.githubusercontent.com/ros/rosdistro/master/ros.asc | sudo apt-key add -sudo sh -c 'echo "deb [arch=amd64,arm64] http://packages.ros.org/ros2/ubuntu `lsb_release -cs` main" > /etc/apt/sources.list.d/ros2-latest.list'

Install ROS Dashing

  sudo apt update
 
  sudo apt install ros-dashing-ros-base

In order to verify correct installation, run the following commands in terminal:

  sudo apt install ros-dashing-demo-nodes-cpp ros-dashing-demo-nodes-py
 
  source /opt/ros/dashing/setup.bash
 
  ros2 run demo_nodes_cpp talker

With ctrl + alt + F2, switch terminal, login, then run the following commands:

source /opt/ros/dashing/setup.bash
 
ros2 run demo_nodes_py listener

You can switch between terminals with ctrl + alt + F1 and ctrl + alt + F2. You should see a message sent by talker in terminal 1 and receive the same message at terminal 2.