ROS

ROS is an open-source, meta-operating system for your robot. It provides the services you would expect from an operating system, including hardware abstraction, low-level device control, implementation of commonly-used functionality, message-passing between processes, and package management.

ROS 1

Installation

You can install any of the ROS distributions below since they are fully released on AUR.

Noetic ros-noetic-desktop-full^AUR

Noetic is also available through an unofficial user repo: Unofficial user repositories#arch4edu

Melodic ros-melodic-desktop-full^AUR

catkin_make in Melodic

As specified by the ROS wiki, the first catkin_make command in a clean workspace should be:

$ catkin_make -DPYTHON_EXECUTABLE=/usr/bin/python3 -DBOOST_ROOT=/opt/boost1.69 -DBoost_NO_SYSTEM_PATHS=TRUE

Subsequent builds should be done with just

$ catkin_make

Using Catkin/ROS with an IDE

CLion

To make CLion^AUR support ROS packages, you can change the Exec parameter of its desktop file as follows.

~/.local/share/applications/jetbrains-clion.desktop

Exec=bash -i -c "source /home/user/catkin_ws/devel/setup.sh;/opt/clion/bin/clion.sh" %f

However, /home/user/catkin_ws must be exchanged with your Catkin workspace. You can now open a Catkin project without cmake complaining about missing packages, hopefully. If desired or needed you can use Python 3 by adding -DPYTHON_EXECUTABLE=/usr/bin/python3 to the CMake options which can be found in the settings.

catkin build in Melodic

For configuring the systems using the catkin build environment, one have to configure the catkin workspace as usual and run:

$ catkin config -DPYTHON_EXECUTABLE=/usr/bin/python3 -DBOOST_ROOT=/opt/boost1.69 -DBoost_NO_SYSTEM_PATHS=TRUE

Afterwards, use catkin build as normal. Please remember to reconfigure your catkin whenever you delete the configuration files (i.e. the catkin_ws directory)

Rebuild when shared libraries are updated

When you update a library that ROS depends on (e.g. Boost), all packages that link to it must be rebuilt. Most AUR helpers will not detect this situation. The following script will generate a list of all packages that are linked to missing so files:

https://seangreenslade.com/h/snippets/ros-find-outofdate.py

(Note that the script requires pyalpm to be installed.)

ROS 2

Installation

Building using AUR

ros2-iron^AUR package aims to provide an easy way to install ROS 2 on Arch Linux. After installing the package, you need to configure your environment (i.e. source) in order to use ROS 2 — See #Usage Examples.

Distrobox

Distrobox allows to use any Linux distribution inside your terminal [1], including Ubuntu, which in turn allows to run ROS2 natively. Distrobox is available in the official repository as distrobox, and relies on Docker or Podman containers.

Once Ubuntu is up and running, install ROS by reading the official installation guide.

Running on Wayland

Although ROS2 packages run fine on Wayland, graphical applications such as gazebo or rviz2 do not. To make them work, set the environment variable QT_QPA_PLATFORM to xcb. You can later test the result with:

rviz2

Usage Examples

First source the workspace, or change the directory to where you installed as before.

If you are using zsh, change source /opt/ros2/foxy/setup.bash to source /opt/ros2/foxy/setup.zsh

$ source /opt/ros2/foxy/setup.bash

A tip to source workspace is adding a function like this your shell startup file, like .bashrc, .zshrc.

ros2_on(){
     export ROS_DOMAIN_ID=42
     export ROS_VERSION=2
     export ROS_PYTHON_VERSION=3
     export ROS_DISTRO=foxy
     source /opt/ros2/foxy/setup.bash
}

Remember to make any applicable changes, namely changing the ROS_DISTRO variable to the distrobution you have installed.

You can change ROS_DOMAIN_ID to your favourite number, or the number you are actually using.

Functionality comparable to roscore, rosnode, rostopic, rosmsg, rospack, rosrun and rosservice is available via ros2:

$ ros2 -h
usage: ros2 [-h] Call `ros2 <command> -h` for more detailed usage. ... 

ros2 is an extensible command-line tool for ROS 2.

optional arguments:
  -h, --help            show this help message and exit

Commands:
  daemon    Various daemon related sub-commands
  msg       Various msg related sub-commands
  node      Various node related sub-commands
  pkg       Various package related sub-commands
  run       Run a package specific executable
  security  Various security related sub-commands
  service   Various service related sub-commands
  srv       Various srv related sub-commands
  topic     Various topic related sub-commands

  Call `ros2 <command> -h` for more detailed usage.

A typical "Hello World" example starts with running a publisher node:

$ ros2 topic pub /chatter 'std_msgs/String' "data: 'Hello World'"

Then, in another terminal, you can run a subscriber (Do not forget to source the workspace in every new terminal):

$ ros2 topic echo /chatter

List existing nodes:

$ ros2 node list
publisher_std_msgs_String

List topics:

$ ros2 topic list
/chatter

ROS 2's version of rviz is

$ rviz2