Traffic Light Manager

A Dockerized Python application that manages a traffic light state machine, broadcasts the state via UDP, and publishes state and future schedules to a DDS topic.

Features

• State Machine: Manages traffic light states (Green, Orange, Red) with configurable timings.
• UDP Broadcast: Sends the current state and schedule via UDP to a specified host/port (default: localhost:5005).
• DDS Publisher: Publishes state and schedule to a DDS topic (TrafficLightStatus) using eProsima Fast DDS.
• DDS Subscriber: Includes a debug subscriber to verify DDS communication.
• Dockerized: Fully containerized environment with Fast DDS and Python bindings built from source.

Prerequisites

• Docker
• Docker Compose

Getting Started

1. Clone the Repository

git clone <repository-url>
cd traffic-light-manager

2. Build and Run

Use Docker Compose to build the image and start the services (Manager and Subscriber).

docker compose up --build

Note: The initial build may take several minutes as it compiles Fast DDS and its Python bindings from source.

3. Verify Output

You should see output from the traffic-light-subscriber service showing the received states:

traffic-light-subscriber-1  | Received State: 1
traffic-light-subscriber-1  | Timestamp: 1701600000.0
traffic-light-subscriber-1  | Schedule:
traffic-light-subscriber-1  |   - State: 1, Start: 1701600000.00, Duration: 5.0
traffic-light-subscriber-1  |   - State: 2, Start: 1701600005.00, Duration: 2.0
...

To verify UDP output, you can listen on port 5005 (if mapped to host) or check the logs.

Configuration

Environment variables can be set in docker-compose.yml:

• UDP_HOST: Destination host for UDP messages (default: 127.0.0.1).
• UDP_PORT: Destination port for UDP messages (default: 5005).

Project Structure

• src/main.py: Application entry point.
• src/state_machine.py: Traffic light logic.
• src/udp_sender.py: UDP communication.
• src/dds_publisher.py: DDS publisher implementation.
• src/dds_subscriber.py: DDS subscriber for debugging.
• src/TrafficLight.idl: IDL definition for DDS topics.
• Dockerfile: Multi-stage build for Fast DDS and Python environment.

License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.