Smart Parking System (IoT Project)

📖 Overview

• This project implements a Smart Parking System using an ESP32 microcontroller, sensors, and cloud services.
• It combines real-time parking slot monitoring, automated gate control, environment awareness (night mode & rain detection), and a chatbot assistant into a fully connected IoT ecosystem.

⚙️ Tech Stack

• ESP32 → Sensor readings, actuator control, MQTT communication
• HiveMQ Cloud → Secure MQTT broker for device ↔ cloud communication
• Node-RED → MQTT to Supabase data pipeline
• Supabase (Postgres + Auth) → Persistent database + user authentication
• Web App → Web app connected to MQTT + Supabase
• FastAPI + LangChain → AI-powered chatbot interface

🛠️ Hardware Components

• Parking Slots (x4) → IR / PIR sensors to detect occupancy
• RGB LEDs (x4 pairs) → Indicate free (green) or occupied (red) slot
• Gate Sensors → Before & after gate sensors to detect vehicles entering/exiting
• Servo Motors (x2) → Gate barrier + automatic ceiling cover
• Rain Sensor → Detects rainfall, triggers automatic ceiling close
• LDR Sensor → Detects light levels, triggers night mode lighting
• Corner LEDs → Lights for night mode
• Buzzer → Alerts for full parking, rain, or warnings
• LCD I2C Display → Shows parking availability & system status

🚦 System Functionalities

🔐 User Management

• Users register/login via Supabase Auth.
• Flutter App uses this for secure access.

🅿️ Parking Slot Management

• Each slot monitored by sensor.
• Occupied → LED turns red.
• Free → LED turns green.
• Slot changes are published via MQTT → stored in Supabase.
• Manual override possible via MQTT commands.

🚪 Gate Control

• Vehicle detected at entrance → gate opens if slots available.

• Vehicle exits → gate opens to allow departure.

• Gate automatically closes after timeout.

• Publishes status to MQTT → Supabase.

🌙 Night Mode

• LDR sensor detects darkness → activates corner LEDs.

• Can be overridden via MQTT (manual ON/OFF/AUTO).

🌧️ Rain Detection

• Rain sensor detects water → ceiling closes automatically.

• Rain stops → ceiling reopens.

• Warning buzzer triggered when rain starts.

🔔 Alerts & Buzzer

• Parking full → buzzer alert + LCD warning.

• Rain detected → buzzer + LCD warning.

• Alerts published via MQTT.

📟 LCD Display

• Displays available slots, system mode, alerts (Night/Rain).

📡 MQTT Topics (HiveMQ)

• parking/sensors/slots/# → Slot updates

• parking/sensors/environment → Light & rain data

• parking/actuators/gate → Gate control & status

• parking/actuators/ceiling → Ceiling control & status

• parking/actuators/buzzer → Alerts

• parking/control/# → Manual control commands

🌐 Cloud Integration

Node-RED

• Runs a flow that subscribes to MQTT topics.
• Stores sensor & actuator events into Supabase database in real-time.

Supabase

• Stores:

  • users → registered drivers.
  • parking_logs → entry/exit logs.
  • sensor_data → slot, rain, lighting, gate status.

Web App

• Connects to MQTT for live status updates.
• Connects to Supabase for user auth + historical data.
• Provides drivers with parking availability & gate control.

FastAPI Chatbot

• Built using FastAPI + LangChain.

• Connects to Supabase to answer queries like:

  • “How many slots are free now?”
  • “Show my last parking session.”

• Acts as a natural language assistant for the parking system.

🚀 Setup & Deployment

1️⃣ ESP32

• Flash the provided Arduino code to the ESP32.

• Update WiFi & MQTT credentials.

2️⃣ HiveMQ

• Create a free HiveMQ Cloud account.

• Replace mqtt_server, mqtt_user, mqtt_password in ESP32 code.

3️⃣ Node-RED

• Import the provided node-red-flow.json.
• Configure Supabase REST API endpoint & key.

4️⃣ Supabase

• Create tables: users, parking_logs, sensor_data.
• Enable Auth for Flutter app.

5️⃣ Web App

• Connect to Supabase (for auth + logs).
• Subscribe to MQTT topics for live updates.

6️⃣ FastAPI Chatbot

• Deploy chatbot with pythoneverywhere.
• Connect Supabase API + LangChain for natural language answers.

🚀 System Architecture Diagram

flowchart TB
    ESP32["ESP32 (Sensors & Actuators)"] <--> MQTT["MQTT Broker (HiveMQ)"]
    MQTT --> NodeRED["Node-RED"]
    NodeRED --> Supabase["Supabase (Database + Auth)"]
    Supabase --> WebApp["Web App"]
    WebApp <---> FastAPI["FastAPI + LangChain Chatbot"]
    FastAPI --> MQTT
    Supabase --> FastAPI                                                                             

Loading