MQ2 Gas Sensor Module (LPG, Smoke, Methane Detection)

The MQ2 Gas Sensor Module is one of the most popular and affordable gas detection sensors used in electronics and IoT projects. It is widely used by students, engineers, and hobbyists in Bangladesh for detecting combustible gases such as LPG, methane, propane, hydrogen, and smoke.

This module is highly compatible with platforms like Arduino, ESP32, Raspberry Pi, making it ideal for gas leakage detection systems, fire alarms, and smart home safety projects.

The MQ2 sensor works based on a tin dioxide (SnO2) semiconductor, which changes its resistance when exposed to gases. The module provides both analog and digital outputs, allowing flexible integration into different systems.

Features:

• Detects LPG, methane, propane, hydrogen, smoke, alcohol
• Dual output: Analog + Digital
• Adjustable sensitivity via onboard potentiometer
• Fast response and recovery time
• Simple interface for microcontrollers
• Long lifespan and stable performance
• Cost-effective for student projects in Bangladesh

Specifications:

MQ2 Sensor Pinout:

• VCC → 5V
• GND → Ground
• A0 → Analog Output
• D0 → Digital Output

Use Cases:

• Gas leakage detection in homes (LPG cylinder safety)
• Smart kitchen monitoring system
• Industrial gas safety projects
• Fire alarm systems
• Arduino/IoT academic projects
• Robotics competitions & university labs

How It Works:

The MQ2 sensor contains a heating element and sensing layer. When gas is present:

• Gas concentration increases
• Sensor resistance changes
• Output voltage varies
• Microcontroller reads the value