micro-ROS module for Raspberry Pi Pico SDK

Getting Started

Here is a quick way to compile the example given in this repository.

Dependencies

micro-ROS precompiled library is compiled using arm-none-eabi-gcc 9.3.1, a compatible version is expected when building the micro-ROS project. You can specify a compiler path with the following command:

# Configure environment
echo "export PICO_TOOLCHAIN_PATH=..." >> ~/.bashrc
source ~/.bashrc

1. Install Pico SDK

First, make sure the Pico SDK is properly installed and configured:

# Install dependencies
sudo apt install cmake g++ gcc-arm-none-eabi doxygen libnewlib-arm-none-eabi git python3
git clone --recurse-submodules https://github.com/raspberrypi/pico-sdk.git $HOME/pico-sdk

# Configure environment
echo "export PICO_SDK_PATH=$HOME/pico-sdk" >> ~/.bashrc
source ~/.bashrc

2. Compile Example

Once the Pico SDK is ready, compile the example:

cd uros_pico_w
mkdir build
cd build
cmake ..
make

To flash, hold the boot button, plug the USB and run:

cp pico_micro_ros_example.uf2 /media/$USER/RPI-RP2

3. Start Micro-ROS Agent

Micro-ROS follows the client-server architecture, so you need to start the Micro-ROS Agent. You can do so using the micro-ros-agent Docker:

docker run -it --rm -v /dev:/dev --privileged --net=host microros/micro-ros-agent:humble upd4 --port 4444

Or using the snap agent:

#Install
sudo snap install micro-ros-agent
#Run
micro-ros-agent udp4 --port 4444 # add -v[1-6] to specify verbosity

Or directly in your ros ecosystem running the micro-ros-agent node micro-ros-agent node:

# Download micro-ROS-Agent packages
ros2 run micro_ros_setup create_agent_ws.sh

# Build step
ros2 run micro_ros_setup build_agent.sh
. install/local_setup.bash

# Run a micro-ROS agent
ros2 run micro_ros_agent micro_ros_agent udp4 --port 4444

What files are relevant?

• pico_wifi_transport.c: Contains the board specific implementation of the wifi transport (no change needed).
• CMakeLists.txt: CMake file.
• pico_micro_ros_example.c: The Picobot ROS 2 exemple.

How to build the precompiled library

Micro-ROS is precompiled for Raspberry Pi Pico in libmicroros. If you want to compile it by yourself:

docker pull microros/micro_ros_static_library_builder:humble
docker run -it --rm -v $(pwd):/project microros/micro_ros_static_library_builder:humble

Note that folders added to microros_static_library/library_generation/extra_packages and entries added to microros_static_library/library_generation/extra_packages/extra_packages.repos will be taken into account by this build system.

How to use Pico SDK?

Here is a Raspberry Pi Pico C/C++ SDK documentation: https://datasheets.raspberrypi.org/pico/raspberry-pi-pico-c-sdk.pdf

Purpose of the Project

This software is not ready for production use. It has neither been developed nor tested for a specific use case. However, the license conditions of the applicable Open Source licenses allow you to adapt the software to your needs. Before using it in a safety relevant setting, make sure that the software fulfills your requirements and adjust it according to any applicable safety standards, e.g., ISO 26262.

License

This repository is open-sourced under the Apache-2.0 license. See the LICENSE file for details.

For a list of other open-source components included in this repository, see the file 3rd-party-licenses.txt.

Known Issues/Limitations

There are no known limitations.