OCPP Backend

This project is an OCPP (Open Charge Point Protocol) backend built using Django and Django Channels. It manages WebSocket connections from EV chargers and processes OCPP 1.6 messages.

Tech Stack

• Django backend
• Django Channels (ASGI) for WebSockets
• Python OCPP 1.6 library

Architectur Diagram

+-----------------+          WebSocket (OCPP 1.6)          +--------------------+
|                 | -------------------------------------> |                    |
|   EV Charger    |                                       | Django Channels     |
| (Charge Point)  | <------------------------------------- |   Consumer         |
+-----------------+          OCPP Responses               | (WebSocket Handler) |
                                                        /  +--------------------+
                                                       /
                                                      /  forwards messages to
                                                     /
                                     +----------------------------+
                                     |        OCPPHandler         |
                                     | - Validate OCPP Actions    |
                                     | - Process OCPP Messages    |
                                     +----------------------------+
                                                       |
                                                       |
                                       persists state to / retrieves session
                                                       |
                                     +----------------------------+
                                     |      ChargerSession        |
                                     | - Maintain connection info |
                                     | - Last heartbeat timestamp |
                                     | - Charger status           |
                                     +----------------------------+

Features

• WebSocket-based communication with EV chargers using OCPP 1.6.
• Tracks charger sessions and handles heartbeat, boot notifications, and more.
• RESTful API for charger management.
• Simulator script (ocpp_simulator.py) to test the system.

🏗️ Folder Structure

ocpp_backend
├── chargers               # Charger app handling OCPP messages
│   ├── chargerSession.py  # Handles charger session state
│   ├── consumers.py       # WebSocket consumer for charger connections
│   ├── ocpp_handler.py    # Processes OCPP messages
│   ├── models.py          # Database models
│   ├── routing.py         # WebSocket routing
│   ├── views.py           # REST API views
│   ├── admin.py, apps.py, tests.py  # Django app files
├── ocpp_backend           # Main Django project folder
│   ├── settings.py        # Project settings
│   ├── asgi.py            # ASGI server configuration (WebSockets)
│   ├── urls.py            # URL routing
│   ├── wsgi.py            # WSGI server configuration
├── ocpp_simulator.py      # Simulator for testing OCPP messages
├── manage.py              # Django management script
├── requirments.txt        # Dependencies

---

🛠️ Installation & Setup

1️⃣ Clone the Repository

git clone git@github.com:Mostafa95/ocpp_module.git
cd ocpp_backend

2️⃣ Create a Virtual Environment & Install Dependencies

python3 -m venv env
source env/bin/activate

pip install -r requirments.txt

3️⃣ Apply Migrations & Start Django Server

python manage.py migrate
python manage.py runserver

The Django server will start at http://127.0.0.1:8000/

---

⚡ Running the OCPP WebSocket Server

To enable WebSocket communication for chargers:

daphne -b 0.0.0.0 -p 8000 ocpp_backend.asgi:application -v2

This will listen for WebSocket connections at:

ws://127.0.0.1:8000/ws/ocpp/<charger_id>/

---

🏎️ Running the OCPP Simulator

You can simulate an EV charger connecting to the backend:

python ocpp_simulator.py

This will send test OCPP messages (e.g., BootNotification, Heartbeat) to the server.

---

📡 API Endpoints

🔹 WebSocket Endpoint

• ws://127.0.0.1:8000/ws/ocpp/<charger_id>/
  • Handles OCPP 1.6 messages
  • Expects JSON-formatted messages

🔹 REST API Endpoints

Method	Endpoint	Description
GET	/chargers/	List all chargers
GET	/chargers/<id>/status	Retrieve charger details
GET	get_logs/	retrieve logs

For further issues, check the logs using:

tail -f logs/events.log