Attributes

Brand	-
Category	Robotics / STEM Teaching Tools / Sensors
Origin	-
Sensor Type	MQ-2 Semiconductor Gas Sensor
Detectable Gases	LPG, Propane, Hydrogen, Methane, Smoke
Operating Voltage	5V DC
Output Signal	Digital Switch Output (0 and 1) & Analog Voltage Output
Preheat Time	Approx. 24 hours for stable readings
Concentration Range	300 to 10,000 ppm
Load Resistance	Adjustable via onboard potentiometer
Interface	3-pin connector (VCC, GND, DO/AO)
Dimensions	32mm x 20mm x 15mm
Compatibility	Arduino, Raspberry Pi, ESP8266, STM32

6 reviews

Anonymous

Mar 30, 2026

Rating: 4/5

Good value but needs patience

The module is well-built and the sensitivity adjustment pot is useful. Just remember that it needs a long preheat time (about a day) before the readings stabilize. Once warmed up, it's quite accurate.

Anonymous

Mar 29, 2026

Rating: 4/5

Solid performance for the price

I integrated this into a custom smoke detector prototype. The digital threshold is easy to set with the screwdriver. It's not industrial grade, but for prototyping and DIY projects, it cannot be beaten at this price point.

Anonymous

Mar 28, 2026

Rating: 5/5

Perfect for my home safety project

This sensor works exactly as described. I connected it to an Arduino Uno and had it detecting LPG within minutes after the initial preheat. The analog output is very responsive to changes in gas concentration.

Anonymous

Mar 25, 2026

Rating: 5/5

Easy to use for beginners

As someone new to sensors, I found the pinout very straightforward. VCC, GND, and Data. The online tutorials for MQ-2 are plentiful, and this module followed all of them perfectly. No issues so far.

Anonymous

Mar 04, 2026

Rating: 5/5

Great for educational kits

We bought ten of these for our student robotics kits. They are robust enough to handle beginner wiring mistakes and provide clear digital signals for simple alarm circuits. Highly recommended for schools.

Anonymous

Mar 04, 2026

Rating: 3/5

Works but gets hot

The sensor detects gas well, but the heating element gets quite hot during operation. Make sure your enclosure has ventilation. Also, ensure you don't touch the sensor mesh while it is powered on.

5 FAQ

Q: Is the digital output active high or active low?

A: The digital output is typically active low. This means the DO pin goes LOW (0V) when the gas concentration exceeds the threshold set by the potentiometer, and HIGH (5V) when the air is clean.

Q: Can this detect carbon monoxide (CO)?

A: The MQ-2 is primarily sensitive to LPG, propane, hydrogen, and smoke. For Carbon Monoxide detection, we recommend using the MQ-7 sensor module, which is specifically tuned for CO.

Q: How long does the sensor actually need to preheat?

A: For initial stabilization, we recommend powering the sensor for 24 to 48 hours. After the first burn-in, it usually only requires a few minutes of preheating upon subsequent power-ups to function correctly.

Q: What is the purpose of the two pairs of pins on the sensor element?

A: One pair connects to the internal heating element required to maintain the operating temperature. The other pair connects to the sensing electrode that changes resistance based on gas concentration.

Q: Does this module work with 3.3V logic levels like the ESP32?

A: Yes, the module operates at 5V, but the digital output is generally compatible with 3.3V microcontrollers. However, for the analog output, you may need a voltage divider if your MCU's ADC cannot handle 5V input.

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