Overview

Pico-ROS is a lightweight ROS (Robot Operating System) client implementation designed for resource-constrained devices. Built on top of zenoh-pico and working in conjunction with rmw-zenoh, it provides an easy-to-use interface to ROS host from embedded systems.

Pico-ROS targets resource-constrained microcontroller-based nodes and edge devices in ROS networks.

Features

Core Components

1. picoros

   • A lightweight ROS client implementation providing core abstractions:
     • Node
     • Publisher
     • Subscriber
     • Service server
     • Service client

2. picoserdes

   • CDR serialization/deserialization for ROS messages
   • Custom type generation from header files.

3. picoparams

   • Parameter server implementation built using picoros and picoserdes
   • Customizable parameter backend interface
   • Compatible with ROS 2 parameter services

Getting Started

Prerequisites

• C compiler and CMake build system
• zenoh-pico
• Micro-CDR
• rmw-zenoh (for ROS 2 integration)

Building the Project

git clone <repo>
cd <repo_path>
git submodule update --init --recursive
mkdir build
cd build
cmake ..
make

Build Options

• Custom type definitions: -DUSER_TYPE_FILE=user_types.h
• Disable examples: -DPICOROS_BUILD_EXAMPLES=OFF
• Disable tests: -DPICOROS_BUILD_TESTS=OFF

Examples

The project includes several example applications demonstrating different features:

• talker.c & talker.cpp: Basic publisher example
• listener.c: Basic subscriber example
• srv_server_add2ints.c: Service server example
• srv_client_add2ints.c: Service client example
• params_server.c: Parameter server implementation
• odometry_publisher.c & odometry_listener.c: ROS odometry message handling
• batteryState_publisher.c BatteryState message with sequence fields.
• jointState_publisher.cpp JointState message with sequence fields in cpp.

Running the Examples

1. Ensure ROS 2 is running with rmw_zenoh (Installation Guide)

2. In separate terminals, run the example nodes:

   # Terminal 1: Run publisher
   ./talker -m client -a <zenoh-router-address>
   
   # Terminal 2: Run subscriber
   ./listener -m client -a <zenoh-router-address>
   
   # Terminal 3: Run service server
   ./srv_add2ints -m client -a <zenoh-router-address>
   
   # Terminal 4: Run parameter server
   ./param_server -m client -a <zenoh-router-address>

3. Interact with nodes from ROS 2:

   # Subscribe to messages
   ros2 topic echo /picoros/chatter
   
   # Call service
   ros2 service call /picoros/add2 example_interfaces/srv/AddTwoInts '{a: 1, b: 2}'
   
   # List parameters
   ros2 param list /picoros

Documentation

The project uses Doxygen for documentation. To generate and read:

# Install dependencies:
sudo apt-get install doxygen graphviz

# Generate documentation:
cd docs
./generate.sh

# View documentation:
# Open in your default browser
xdg-open docs/generated/html/index.html

Using in your project

See the examples directory for implementation references.

Automatic generation of user_types.h file can be done using scripts in /tools/type-gen. Format of the file is descibed in picoserdes.h. Example with standard ROS types can be found in example_types.h.

For compatibility with rmw_zenohd default configuration, set matching zenoh-pico lease duration settings with defines or edit the zenoh-pico config.h file:

• -DZ_TRANSPORT_LEASE=60000 and
• -DZ_TRANSPORT_LEASE_EXPIRE_FACTOR=2

Example projects

• picoros-examples
• roscon2025_control_workshop

Help us add more!

License

See LICENSE file for details.