🤖ROS and ROS2

ROS Interface

There's also a ROS wrapper for developpers to easily connect to the ROS environment. This ROS wrapper contains two branches: ROS1 and ROS2. It is recommended to use ROS with Raspberry Pi.

Note:

ROS1 and ROS2 are not directly compatible, but you can achieve limited interoperability through the following methods:

1. System Coexistence: Both ROS1 and ROS2 can be installed on the same device, but they are used by switching environment variables and cannot be activated at the same time.

2. Communication Bridge: Communication between the two requires the ros1_bridge tool to bridge messages. Note that this only supports a limited number of standard message types.

3. Development Differences: ROS1 code cannot be reused directly. Adjustments are required for ROS2 syntax (such as message types starting with a capital letter) and APIs.

Using ROS on Raspberry Pi

Currently, it's recommended to install ROS using docker.

• install docker on Raspberry Pi (ref)

sudo apt-get update && sudo apt-get upgrade
curl -fsSL https://get.docker.com -o get-docker.sh
sudo sh get-docker.sh
sudo usermod -aG docker pi
# test installation
docker run hello-world

• prepare workspace

mkdir -p workspace/src
cd workspace/src
git clone https://github.com/PetoiCamp/ros_opencat
cd ros_opencat
git submodule init && git submodule update
cd ../../..

• run the container

docker run -v path/to/workspace:/workspace \
-it --rm --privileged --network host --name ros ros:noetic-robot

• source files and build inside the container

cd /workspace
source /opt/ros/noetic/setup.bash
catkin_makbase
source devel/setup.bash

• run examples (see Examples for more)

rosrun opencat_examples opencat_examples_serial

Using ROS for remote control

Ros is designed with distributed computing in mind. Here's a simple example on how to run nodes on different machines.

• on host machine (usually more powerful than Raspberry Pi)

# launch server
roscore

• run service node on Raspberry Pi

export ROS_MASTER_URI=http://<Host_IP>:11311/
rosrun opencat_server opencat_service_node

• send command from host

rosrun opencat_examples opencat_examples_client_cpp

Examples

• using serial library

rosrun opencat_examples opencat_examples_serial

• using ROS service

# start core
roscore
# start service server
rosrun opencat_server opencat_service_node
# examples using oppencat ros service in C++
rosrun opencat_examples opencat_examples_client_cpp
# examples using opencat ros service in python
rosrun opencat_examples opencat_examples_client_py

Projects

There are some great projects with ROS2 from the users who contributed:

• Bittle_ROS2

• FinoBot

Note: