Arm kit installation process

How to install your Arm kit.

You decided to buy an Arm kit, you have a few things to install on your computer. Don’t worry, we will go step by step to guide you through the installation process!

What do I need?

To program and control your robot, you have two main options:

  • Directly control it via ROS2 Foxy: this gives you lower level access to the robot and full interoperability with ROS. Yet ROS can be complex, so if you are not familiar with it, that’s probably not what you are looking for.
  • Use our specific Python SDK: simple Python’s API to let you quickly start controlling your robot. It gives you access to all main robot features. If you are not familiar with ROS, we advise you to use our SDK first.

In the following, we will show you how to install everything needed to start programming your robot. If you want to only use ROS2, we will tell you which steps can be skipped.

The low-level software used to control the robot has been developed to work on Linux Ubuntu 20.04. While it should work on other OS, we strongly recommend using the same version.

Reachy runs on ROS 2 Foxy. So first of all, you need to install it.
For more information on ROS2 and how to install it, please refer to the official documentation:

You will also need to install colcon the build tool from ROS2.

sudo apt install python3-colcon-common-extensions

Create a ROS workspace for Reachy

Note: If you are familiar with ROS2, please feel free to use your custom installation.

Now that you have installed ROS, you need to create a ROS workspace to install the specific ROS packages for Reachy.

Create it in your $HOME folder:

mkdir -p ~/reachy_ws/src

Build your empty workspace once to set everything up.

cd ~/reachy_ws
source /opt/ros/foxy/setup.bash
colcon build 

Once done, add commands to your .bashrc file so that you won’t have to type them in each new terminal.

echo "source /opt/ros/foxy/setup.bash" >> ~/.bashrc
echo "source /home/reachy/reachy_ws/install/setup.bash" >> ~/.bashrc
echo "source /usr/share/colcon_cd/function/" >> ~/.bashrc
echo "export _colcon_cd_root=~/ros2_install" >> ~/.bashrc

Finally, source your .bashrc file:

source ~/.bashrc

Clone the requested ROS repositories from GitHub

In ~/reachy_ws/src, clone the following repositories (check here if you are not familiar with git):

To use Reachy directly with ROS:

To use Reachy through the SDK:

cd ~/reachy_ws/src
git clone
git clone
git clone
git clone

Once everything cloned in your ROS2 workspace, build the packages:

cd ~/reachy_ws
colcon build

Open ports for serial use

By default, on a Ubuntu install, when using serial, users do not have the right to access the ports. Give rights to open /dev/ttyUSB ports:

sudo usermod -a -G tty <usr_name>
sudo usermod -a -G dialout <usr_name>

Clone the other requested repositories from Github

Create another folder dev that will contain all the packages used with Reachy that are not based on ROS.

mkdir ~/dev

In this folder you will need the following repositories:

Requested in all cases:

To use Reachy through the SDK:

cd ~/dev
git clone
git clone

Then install them

cd ~/dev/reachy_pyluos_hal
pip3 install -e .

cd ~/dev/reachy-sdk-api
pip3 install -e python

reachy-sdk can either be installed from source or using pip.

  • from source
cd ~/dev
git clone
cd ~/dev/reachy-sdk
pip3 install -e .
  • using pip
pip3 install reachy-sdk

To learn more on the repositories content and usage, please refer to files in each repository.

Install the dependencies

Some Python dependencies need to be installed as extra.
Dependencies: numpy, scipy, pyquaternion, zoom_kurokesu, pykdl

If one of them is missing:

  • Using pip install:
pip3 install numpy
pip3 install scipy
pip3 install pyquaternion
pip3 install zoom_kurokesu
  • Using apt install:
sudo apt install python3-pykdl

We also recommend you to install the jupyter and matplotlib libraries.

pip3 install jupyter
pip3 install matplotlib

Set the correct configuration file

As Reachy software is meant to work with different robot configurations. Several configuration files are available.

By default, the configuration is set to a full robot. You need to modify it to your own configuration.

Open .bashrc:

nano ~/.bashrc

And add an environment variable REACHY_MODEL that designates your model.
For example, to configure only a right arm:

export REACHY_MODEL="robotic_arm_right"

Make sure to source your bashrc file to take the modification into account:

source ~/.bashrc

To use other methods to change your configuration, please read ~/dev/reachy_pyluos_hal/reachy_pyluos_hal/tools/ or go to

Start everything up

If you are using ROS, you will find launch files in each of our ROS packages to set them up. In particular, you can run:

ros2 launch reachy_kinematics  
# (for description and kinematics)
ros2 launch reachy_controllers  
# (for joint_state, joint_goals, fans, sensors, etc.) 

If you want to use the SDK, we provide a specific launcher file that starts everything (including the above mentioned ROS packages) at once:

ros2 launch reachy_sdk_server

Generate a system.d file for auto-startup

If you want the reachy_sdk_server launch file to be started automatically when your computer starts, you can use our systemd file:

cd ~/reachy_ws/src/reachy_sdk_server
bash generate-service-file.bash

This command should have created a file called reachy_sdk_server.service. To activate this service, you need to copy it to systemd:

sudo cp reachy_sdk_server.service /etc/systemd/system

Enable it for the service to be launched automatically when you restart your computer:

sudo systemctl enable reachy_sdk_server.service

You can manually start it doing:

sudo systemctl start reachy_sdk_server.service

Note: You need to connect the arm to your computer before starting a service. If you enabled the service, connect your arm to your computer before turning it on.

For more information on the services, please refer to section Using services.

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