Attributes

Brand	-
Category	Robotics / STEM Teaching Tools / Sensors
Origin	-
Sensor Type	MQ-2 Semiconductor Gas Sensor
Detectable Gases	LPG, i-butane, propane, methane, alcohol, hydrogen, smoke
Operating Voltage	5V DC
Output Signal	Digital Switch Output (0 and 1) & Analog Output
Preheat Time	Approximately 24-48 hours for stable readings
Sensitivity Adjustment	Adjustable via onboard potentiometer
Interface Module Size	32mm x 20mm x 10mm
Fixed Hole Installation	4mm diameter mounting holes
Comparator Chip	LM393 Wide Voltage Comparator
Application Scope	Home safety alarms, industrial gas detection, DIY electronics

6 reviews

Anonymous

Mar 31, 2026

Rating: 5/5

Excellent sensitivity

I tested this against a professional meter, and while it's not lab-grade precision, it is perfectly adequate for hobbyist safety applications. It picked up alcohol vapors immediately.

Anonymous

Mar 22, 2026

Rating: 4/5

Good sensor, requires patience

The hardware works exactly as described. Just remember that it needs a long preheat time (about a day) before the readings stabilize. Once warmed up, it detects smoke from a match instantly.

Anonymous

Mar 18, 2026

Rating: 5/5

Solid build quality

The PCB looks clean and the soldering points are clear. I integrated three of these into my smart home system to monitor different rooms. No false alarms so far after calibration.

Anonymous

Mar 14, 2026

Rating: 5/5

Perfect for my home safety project

I used this MQ2 module to build a custom kitchen gas alarm. The analog output is very responsive to changes in air quality, and the digital threshold is easy to set with the small screwdriver. Great value for the price.

Anonymous

Mar 12, 2026

Rating: 5/5

Reliable and easy to interface

Connected this directly to my ESP32 without any issues. The voltage comparator chip makes it very easy to get a clean HIGH/LOW signal for triggering alarms. Highly recommended for beginners.

Anonymous

Mar 10, 2026

Rating: 4/5

Great for learning

Bought a pack of five for my students. They are robust and handle 5V logic well. The only downside is the power consumption when the heater is active, but that is expected for this type of sensor.

5 FAQ

Q: Is the enclosure included waterproof?

A: No, this is a bare module intended for integration into custom enclosures. The sensor elements should be protected from direct water exposure and dust for longevity. Please house it in a ventilated but protected case.

Q: How long does the sensor need to warm up before use?

A: For accurate and stable readings, the MQ2 sensor element requires a preheat time of approximately 24 to 48 hours upon first use or after being disconnected for a long period.

Q: Does this module work with 3.3V microcontrollers like the ESP8266?

A: Yes, the module operates at 5V, but the output signals are generally compatible with 3.3V logic. However, for optimal stability, we recommend using a level shifter or powering the module via a 5V pin if your board provides one.

Q: What is the purpose of the two output pins?

A: The module provides both an Analog Output (AO) which gives a voltage proportional to gas concentration, and a Digital Output (DO) which goes HIGH or LOW when the concentration exceeds the threshold set by the potentiometer.

Q: Can this detect carbon monoxide specifically?

A: The MQ2 is primarily sensitive to LPG, propane, methane, alcohol, hydrogen, and smoke. While it may show some reaction to carbon monoxide, the MQ-7 model is specifically designed and calibrated for better CO detection.

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