🔥 Gas Safety Monitoring System

A real-time LPG gas leak detection and alert system built with ESP32, Flask, and a web-based dashboard. The system monitors gas concentration levels, triggers physical safety mechanisms (servo valve shutoff, relay, buzzer), and sends email alerts when dangerous levels are detected.

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📋 Table of Contents

• Features
• System Architecture
• Gas Level States
• Hardware Components
• Pin Configuration
• Software Setup
• Environment Variables
• How It Works
• API Endpoints

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✨ Features

• Real-time gas monitoring with live dashboard updates every second
• Three-state detection system — Safe, Warning, and Danger
• Automatic gas valve shutoff via servo motor when danger is detected
• Buzzer alarm with mute control from the web dashboard
• Relay control for additional safety mechanisms
• Email alerts via Brevo (formerly Sendinblue) API on high gas levels
• Concentration history chart with real-time graph
• Responsive dark-themed dashboard built with Tailwind CSS
• Cloud deployment ready (designed for Render)

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🏗 System Architecture

┌──────────────┐        HTTP POST /update        ┌──────────────────┐
│   ESP32 +    │ ──────────────────────────────►  │  Flask Backend   │
│  MQ Gas      │                                  │  (backend.py)    │
│  Sensor      │  ◄──────────────────────────────  │                  │
│              │     JSON response (mute cmd)      │  Brevo Email API │
└──────────────┘                                  └────────┬─────────┘
   │  Servo (valve)                                        │
   │  Relay                                     GET /data  │
   │  Buzzer                                               ▼
                                                 ┌──────────────────┐
                                                 │  Web Dashboard   │
                                                 │  (index.html)    │
                                                 │  Polls every 1s  │
                                                 └──────────────────┘

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🚦 Gas Level States

The system classifies gas concentration into three states:

✅ Safe (0 – 1000 ppm)

All systems nominal. No action required.

⚠️ Warning (Above 1000 ppm)

Elevated gas levels detected. Monitor closely.

🚨 Danger (Above 2000 ppm)

Critical gas concentration! The system automatically:

• Activates the buzzer alarm
• Rotates the servo to shut off the gas valve
• Triggers the relay
• Sends an email alert
• Displays an alert banner on the dashboard

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🔧 Hardware Components

Component	Description
ESP32	Microcontroller with WiFi
MQ Gas Sensor	LPG/combustible gas detection
Servo Motor	Gas valve shutoff mechanism
Relay Module	Additional safety control (active low)
Buzzer	Audible alarm

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📌 Pin Configuration

Pin	Component
34	Gas Sensor (Analog)
18	Servo Motor
27	Relay
26	Buzzer

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💻 Software Setup

Prerequisites

• Python 3.x
• Arduino IDE (for ESP32 flashing)
• ESP32 board package installed in Arduino IDE

Backend Setup

1. Clone the repository

   git clone https://github.com/your-username/gas-safety-dashboard.git
   cd gas-safety-dashboard

2. Install dependencies

   pip install -r requirements.txt

3. Set environment variables (see Environment Variables)

4. Run the server

   python backend.py

   The server starts on http://localhost:5000

ESP32 Setup

1. Open Gas_Safety_esp32Code.ino in Arduino IDE
2. Update WiFi credentials:

   const char* ssid = "YOUR_WIFI_SSID";
   const char* password = "YOUR_WIFI_PASSWORD";

3. Update the server URL to point to your deployed backend:

   const char* serverName = "https://your-server-url.com/update";

4. Flash the code to your ESP32

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🔐 Environment Variables

Variable	Description
BREVO_API_KEY	API key for Brevo email service
EMAIL_SENDER	Sender email address for alerts
EMAIL_RECEIVER	Recipient email address for alerts
PORT	Server port (default: 5000)

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⚙️ How It Works

1. The ESP32 reads the gas sensor value every 200ms
2. If gas stays above 2000 ppm for 8 seconds, the system activates:
   • Servo rotates to 90° (shuts gas valve)
   • Relay turns ON
   • Buzzer starts ringing
3. Data is sent to the Flask backend every 5 seconds via HTTP POST
4. The backend triggers an email alert via Brevo when gas exceeds the threshold
5. The web dashboard polls the backend every 1 second and updates the UI
6. If gas drops below 1800 ppm:
   • Buzzer turns off after 5 seconds
   • Full system resets after 60 seconds below threshold
7. The buzzer can be muted remotely from the dashboard

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🌐 API Endpoints

Method	Endpoint	Description
GET	/	Serves the web dashboard
GET	/data	Returns latest gas data as JSON
POST	/update	Receives gas data from ESP32
POST	/mute	Sends mute command to ESP32
GET	/force-email	Triggers a test email alert
GET	/health	Health check endpoint

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📁 Project Structure

├── backend.py                  # Flask server & email logic
├── Gas_Safety_esp32Code.ino    # ESP32 Arduino code
├── requirements.txt            # Python dependencies
├── templates/
│   └── index.html              # Web dashboard
├── static/
│   └── screen.png              # Dashboard screenshot
└── Readme_images/
    ├── SAFE.png                # Safe state screenshot
    ├── WARNING.png             # Warning state screenshot
    └── DANGER.png              # Danger state screenshot