// Pin Definitions #define MQ2PIN A0 // MQ-2 analog output to Analog Pin A0 #define BUZZER 8 // Buzzer connected to Digital Pin 8 #define LED 9 // LED connected to Digital Pin 9 // Smoke detection ...

This project uses an MQ2 gas sensor, relay module (for motor or exhaust fan), buzzer, and LEDs to create a complete gas leakage detection and alert system using Arduino. When gas concentration crosses ...