The MQ-2 Gas Sensor Module is a widely used gas detection sensor capable of sensing flammable gases and smoke. It works using a tin dioxide (SnO₂) sensing material, whose resistance changes when exposed to combustible gases. The module includes a comparator circuit (LM393) and provides both analog and digital outputs, allowing it to be easily interfaced with microcontrollers. A built-in potentiometer allows users to adjust the sensitivity level. Due to its reliability and low cost, the MQ-2 sensor is commonly used in gas leakage alarms, safety monitoring systems, air quality monitoring, and smart home automation projects. Key Features Detects LPG, methane, propane, hydrogen, and smoke Adjustable sensitivity using onboard potentiometer Both analog and digital output Onboard power and status LED indicators Easy interface with Arduino and other microcontrollers Fast response and high sensitivity Technical Specifications Parameter Value Operating Voltage 5V Sensor Type Gas / Smoke Sensor Detection Gases LPG, Methane, Propane, Hydrogen, Smoke Output Type Analog and Digital Comparator IC LM393 Preheat Time ~20 seconds Pin Configuration Pin Description VCC Power Supply (5V) GND Ground DO Digital Output AO Analog Output
