Gas Leak Detection System

Intelligent LPG gas leak detection system on ESP32 with machine learning early detection, OpenAI alerts, MQTT, Telegram, and a local web dashboard.

Features

• ML-based early leak detection (EMA gradient)
• OpenAI API for dynamic warning messages
• MQTT publishing for external dashboards
• Local web dashboard at ESP32 IP
• Telegram instant notifications
• OTA wireless firmware updates
• Watchdog timer for stability
• AP fallback mode if WiFi fails

Hardware Required

Component	Quantity
ESP32 DevKit	1
MQ-2 Gas Sensor	1
MQ-7 Smoke Sensor	1
DHT22 Temperature/Humidity	1
Active Buzzer	1
LED Green / Yellow / Red	3
220 ohm Resistors	3
Push Button	1
Relay Module	1
Solenoid Valve (optional)	1

Pinout

Component	ESP32 Pin
Gas Sensor (Analog)	GPIO 34
Smoke Sensor (Analog)	GPIO 35
DHT22 Data	GPIO 4
Solenoid	GPIO 26
Relay	GPIO 27
Buzzer	GPIO 14
LED Green	GPIO 12
LED Yellow	GPIO 13
LED Red	GPIO 15
Reset Button	GPIO 0
Status LED	GPIO 2

Setup

1. Clone the repository

git clone https://github.com/nn0z/Gas-Detector.git
cd Gas-Detector

2. Create secrets.h

cp secrets.h.example gas_leak_detector/secrets.h

Edit gas_leak_detector/secrets.h and fill in your credentials:

#define WIFI_SSID       "YOUR_WIFI_SSID"
#define WIFI_PASSWORD   "YOUR_WIFI_PASSWORD"
#define OPENAI_API_KEY  "YOUR_OPENAI_API_KEY"
#define TELEGRAM_TOKEN  "YOUR_TELEGRAM_BOT_TOKEN"
#define TELEGRAM_CHAT   "YOUR_TELEGRAM_CHAT_ID"
#define OTA_PASSWORD    "YOUR_OTA_PASSWORD"
#define AP_PASSWORD     "YOUR_AP_PASSWORD"

OpenAI and Telegram are optional. Leave them empty if not used.

3. Install libraries

In Arduino IDE, go to Sketch > Include Library > Manage Libraries and install:

• PubSubClient
• ArduinoJson
• DHT sensor library
• Adafruit Unified Sensor

4. Install ESP32 board package

Go to File > Preferences and add this URL to "Additional Boards Manager URLs":

https://espressif.github.io/arduino-esp32/package_esp32_index.json

Then go to Tools > Board > Boards Manager, search esp32, and install it.

5. Open and upload

1. Open gas_leak_detector/gas_leak_detector.ino in Arduino IDE
2. Select Tools > Board > ESP32 Dev Module
3. Select your COM port under Tools > Port
4. Click Upload

6. Open Serial Monitor

Set baud rate to 115200. Note the IP address shown.

7. Open web dashboard

Navigate to http://<esp32-ip> in your browser.

MQTT Topics

Topic	Description
gas/leak/data	Sensor readings every 5s
gas/leak/alert	Critical alerts only
gas/leak/stats	Aggregated stats every 30s

Subscribe via HiveMQ WebSocket Client (https://www.hivemq.com/mqtt-websocket-client/):

• Host: broker.hivemq.com
• Port: 8000

Telegram Setup

1. Create a bot via @BotFather
2. Get your chat ID from @userinfobot
3. Fill them in secrets.h

OTA Updates

After first upload, the board appears in Arduino IDE under:

Tools > Port > Network Ports > gas-detector

Security

• Never commit secrets.h
• Regenerate any leaked API keys immediately
• Use secrets.h.example as a template only

---

⭐ Show Your Support

If you like this project, give it a star ⭐ on GitHub!