ROS2 Interface Publisher-Subscriber System

📌 Overview

This project demonstrates a ROS 2-based communication system using a custom message interface. It implements a publisher-subscriber architecture to simulate real-time hardware monitoring (temperature, motor status, debug info).

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🚀 Features

• Custom ROS2 interface (HardwareStatus.msg)
• Publisher node simulating hardware data
• Subscriber node for monitoring system state
• Real-time communication using ROS2 topics
• Clean modular architecture (separate interface + nodes)

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🏗️ Architecture

HardwarePublisher Node
        │
        ▼
   /hardware_status  (Topic)
        │
        ▼
HardwareSubscriber Node

        ↑
 HardwareStatus.msg (Interface)

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📦 Project Structure

interface_ws/
├── src/
│   ├── my_robot_interfaces/
│   │   ├── msg/
│   │   │   └── HardwareStatus.msg
│   │   ├── package.xml
│   │   └── CMakeLists.txt
│   │
│   ├── my_py_pkg/
│   │   ├── my_py_pkg/
│   │   │   ├── hardware_publisher.py
│   │   │   ├── hardware_subscriber.py
│   │   │   └── __init__.py
│   │   ├── package.xml
│   │   ├── setup.py
│   │   └── setup.cfg
│
└── README.md

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🧠 Custom Message Definition

File: HardwareStatus.msg

int64 version
float64 temperature
bool are_motors_ready
string debug_message

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⚙️ Setup & Installation

# Create workspace
mkdir -p ~/interface_ws/src
cd ~/interface_ws/src

# Clone repository
git clone https://github.com/omkar-robotics/ros2-interface-pub-sub.git

# Build workspace
cd ~/interface_ws
colcon build

# Source workspace
source install/setup.bash

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▶️ Usage

Run Subscriber (Terminal 1)

ros2 run my_py_pkg hardware_sub

Run Publisher (Terminal 2)

ros2 run my_py_pkg hardware_pub

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📊 Sample Output

Publishing:
Version: 1
Temperature: 45.3
Motors Ready: True

Received:
Version: 1, Temp: 45.3, Motors: True

High Temperature: 65.0
Motors NOT ready!

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🧩 Technologies Used

• ROS 2 (Humble)
• Python (rclpy)
• Custom Interfaces (.msg)
• Colcon Build System

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📷 Output Preview

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📈 Future Improvements

• Integration with real sensors (camera, temperature)
• ROS2 bag recording for data logging
• Visualization using RViz
• Gazebo simulation integration
• Add service & action interfaces

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👨‍💻 Author

Omkar GitHub: https://github.com/omkar-robotics

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