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Home / Computer Hardware, Monitors & Peripherals / Smoke Sensor Module MQ-2/3/4/5/6/7/8/9, MQ135, Combustible Gas, Alcohol, Carbon Monoxide Detector

Attributes

Brand -
Category Electronic Components / Maker DIY / Computer Hardware, Monitors & Peripherals
Origin -
Sensor Series MQ-2 / MQ-3 / MQ-4 / MQ-5 / MQ-6 / MQ-7 / MQ-8 / MQ-9 / MQ-135
Operating Voltage 5V DC
Output Type Analog (AO) and Digital TTL (DO)
Comparator IC LM393 Wide Voltage Comparator
Sensing Target Combustible Gas, Alcohol, Smoke, CO, Hydrogen
Preheat Duration 24-48 Hours Recommended for Stability
Operating Temperature -10°C to 50°C
PCB Dimensions 32mm x 20mm x 22mm
Interface Pins VCC, GND, Digital Out, Analog Out
Application DIY Electronics, Prototyping, Education, Robotics

5 reviews

A

Anonymous

Apr 01, 2026

Rating: 4/5

Value for money

Cheaper than local electronics stores and works just as well for hobby projects. Shipping was fast.

A

Anonymous

Mar 26, 2026

Rating: 5/5

Perfect for students

Used in our workshop for teaching sensor interfacing. Students found it easy to integrate with Arduino boards.

A

Anonymous

Mar 05, 2026

Rating: 5/5

Solid build quality

PCB looks professional and soldering points are clear. The header pins were included which was a nice touch.

A

Anonymous

Feb 28, 2026

Rating: 4/5

Good sensitivity

Takes time to warm up as described, but once heated it detects gas changes quickly. Good value for the price.

A

Anonymous

Feb 23, 2026

Rating: 5/5

Works great with ESP32

Connected easily to my ESP32 project. The analog output is smooth and the digital threshold is adjustable via the potentiometer. Great for learning.

5 FAQ

Q: How do I calibrate the sensor?

A: Place the sensor in clean air for the preheat period, then read the baseline analog value to set your threshold.

Q: What is the exact pinout configuration?

A: The pins are labeled on the PCB: VCC for power, GND for ground, DO for digital output, and AO for analog output.

Q: Which model is best for detecting alcohol vapor?

A: The MQ-3 model is specifically optimized for alcohol and ethanol detection compared to the other variants.

Q: Does it work with 3.3V logic microcontrollers?

A: Yes, the digital output is compatible, but we recommend powering the module with 5V for proper heater operation.

Q: Is this certified for home safety alarm systems?

A: No, this module is designed for educational and prototyping purposes only. It is not certified for life-safety applications.

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