Automatic LPG Gas Leakage Detection using Arduino

The Automatic LPG Gas Leakage Detection system uses an Arduino Uno as the central processing unit to continuously monitor air quality for combustible gases. An MQ6 or MQ2 gas sensor is placed in the environment where a leak might occur; as it detects LPG, its analog output changes based on the gas concentration. The Arduino Uno reads this sensor value and compares it against a predefined threshold. If the gas level exceeds the safe limit, the microcontroller triggers an immediate local alarm by activating a buzzer and signaling an LED indicator through a ULN2003 driver circuit. Simultaneously, the system takes automated preventive actions. It utilizes a 5V relay to manage higher-power states if needed and commands an MG996R high torque servo motor to physically actuate and shut off a gas valve, stopping the leak at its source. To ensure remote awareness, the Arduino communicates with a SIM900A GSM module using the SoftwareSerial library, sending an automated SMS text message warning to a pre-programmed emergency contact number. The entire circuit is powered reliably by a 12V 2A adapter, while a breadboard helps organize the low-voltage signal distribution among the sensors and modules.