Sensors 4 pins

MQ-2 Gas Sensor

Gas sensor for LPG, propane, hydrogen, methane, smoke. Analog and digital output.

// connector diagram 4 pins

// loading diagram...

// Specifications

Supply Voltage

Heater Voltage

Gases Detected

LPG, propane, H2, CH4, smoke

Output

Analog + digital threshold

Warm-up Time

20s (stable after 48h burn-in)

Package

Module with 4 pins

// Pin Reference Table

Pin	Name	Function	Type
VCC	VCC	5V power supply	PWR
GND	GND	Ground	GND
DOUT	DOUT	Digital output, HIGH = gas detected	I/O
AOUT	AOUT	Analog output, higher = more gas	ADC

The MQ-2 is a gas sensor sensitive to LPG, propane, hydrogen, methane, and smoke. It has both analog output (concentration level) and digital output (threshold trigger) on the module version. Requires a 24–48 hour burn-in period for stable readings.