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MQ-2 Flammable Gas and Smoke Sensor

Sensor

SnO₂-based gas sensor sensitive to flammable gases such as LPG, propane, methane and hydrogen, and to cigarette smoke; used in gas leak and smoke alarm projects. Its heater makes it warm while it runs; preheat it for at least 24 hours before first use.

Specifications

Detected gases

LPG, propane, methane, hydrogen, alcohol, smoke

Detection range

300 - 10000 ppm

Supply voltage

5V DC

Heater power

≤ 800 mW

Preheating

≥ 24 hours (first use)

Output

Analog (AO) + digital (DO)

Pins

VCC, GND, DO, AO

Shop prices

• RobotzadeIn stock67.20 ₺
• RobocomboIn stock69.00 ₺
• Direnc.netIn stock69.74 ₺
• ElektrovadiIn stock72.14 ₺
• F1 DepoIn stock85.20 ₺
• Modül ElektronikIn stock85.74 ₺
• HatfonIn stock85.74 ₺
• SAMM MarketIn stock88.31 ₺
• Robo90In stock89.28 ₺
• RobotsepetiIn stock101.80 ₺
• Robolink MarketIn stock118.50 ₺
• MotorobitIn stock126.25 ₺
• HobiDevreIn stock144.00 ₺
• KomponentciIn stock177.52 ₺

Prices read from the shops' pages on 22 October 2026. Prices and stock may have changed since; check at the shop before you buy.

Projects with this part

• Smoke and Gas AlarmIntermediate35 minAn alarm that goes off when smoke or a flammable gas (LPG, natural gas, methane) shows up in the kitchen or a room: the MQ-2 sensor's analog output is read, the clean air value is measured at start-up, and once the reading rises well above it the buzzer plays the three-beep pattern (T3) that real smoke alarms use while the red LED flashes with the beeps. The green LED blinks while warming up and stays on once the alarm is armed. It teaches reading an analog sensor against its own clean air value, using two separate thresholds so the alarm does not flicker at the edge, and playing a sound pattern with millis() while still taking readings. No extra library needed. This is a learning project; it does not replace a certified smoke and gas alarm at home.Open project