Description
Reviews
| Brand | - |
| Category | Robotics / STEM Teaching Tools / Sensors |
| Origin | - |
| Model Compatibility | MQ-2, MQ-3, MQ-4, MQ-5, MQ-6, MQ-7, MQ-8, MQ-9, MQ-135 |
| Operating Voltage | 5V DC |
| Output Signal | Digital Switch Output (0 and 1) and Analog Output |
| Detection Range | Varies by specific sensor type (e.g., LPG, Alcohol, CO, Smoke) |
| Interface Type | 3-Pin Connector (VCC, GND, DO/AO) |
| Adjustable Sensitivity | Yes, via onboard potentiometer |
| Indicator LED | Power LED and Digital Switch Output LED |
| PCB Dimensions | 32mm x 20mm x 14mm |
| Primary Application | Gas leakage detection, safety monitoring, DIY electronics projects |
| Package Includes | 1x Sensor Module Board (Sensor chip pre-soldered) |
Anonymous
Mar 31, 2026
Rating: 5/5
Great for learning
Bought this for my university embedded systems class. The documentation online is plentiful, and the analog output allows for detailed data logging. Highly recommend for students.
Anonymous
Mar 29, 2026
Rating: 5/5
Perfect for Arduino Projects
I bought the MQ-2 version for my home safety prototype. It connects easily to my Arduino Uno and the sensitivity adjustment works great. Very responsive to smoke tests.
Anonymous
Mar 26, 2026
Rating: 5/5
Reliable gas detection
Using the MQ-4 for natural gas monitoring in my workshop. The digital output triggers my buzzer alarm instantly when I test it with a lighter nearby. Solid build quality.
Anonymous
Mar 24, 2026
Rating: 5/5
Bulk buy success
Purchased multiple units for our robotics club. All modules arrived in good condition and performed consistently across different microcontrollers including ESP32 and Raspberry Pi.
Anonymous
Mar 24, 2026
Rating: 4/5
Works well, gets hot
The sensor functions perfectly for detecting alcohol vapors with the MQ-3. Note that the heating element gets quite warm during operation, which is normal for this type of sensor. Ensure proper ventilation in your enclosure.
Anonymous
Mar 07, 2026
Rating: 4/5
Good value but needs calibration
The module works as described. Just remember these sensors need a burn-in time of about 24-48 hours before they give stable readings. Once calibrated, the MQ-135 detects air quality changes well.
Q: Does this module work with 3.3V logic microcontrollers like ESP8266?
A: Yes, the digital output is compatible. However, the module itself requires a 5V power supply for the heater. You may need a voltage divider or level shifter if connecting the DO pin directly to a 3.3V GPIO without internal tolerance.
Q: Can I detect Carbon Monoxide with the MQ-2 sensor?
A: No, the MQ-2 is primarily designed for LPG, i-butane, propane, methane, alcohol, hydrogen, and smoke. For Carbon Monoxide detection, please select the MQ-7 or MQ-9 model specifically.
Q: Is this sensor waterproof for outdoor use?
A: No, the bare sensor module is not waterproof. If you plan to use it outdoors, you must house it in an IP-rated enclosure with a breathable membrane to allow gas entry while protecting against rain and dust.
Q: How long does the sensor need to warm up before use?
A: For accurate readings, we recommend powering the sensor for at least 24 to 48 hours initially to burn in the heating element. After the initial burn-in, a warm-up period of 1-2 minutes before each reading session is sufficient.
Q: What is the difference between the DO and AO pins?
A: AO (Analog Output) provides a continuous voltage signal proportional to the gas concentration, allowing you to measure levels. DO (Digital Output) acts as a switch; it goes HIGH or LOW when the gas concentration exceeds the threshold set by the potentiometer.
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