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.
Yandi Retainer Storage Case for Kids - Lightweight Portable Box for Orthodontic Aligners and Dentures
$8.42
Zhizhi Manshu Wen Zhengming Small Regular Script Collection of Twelve Ancient Texts: Yueyang Tower Record, Peach Blossom Spring Record, Farewell to Dongyang Ma Sheng Xu
$68.00
Factory Direct Rubber Molding Tools - Custom Production & Processing
$2,280.00
Catalytic Combustion Waste Gas Treatment Equipment - RCO Activated Carbon Adsorption and Desorption Integrated Machine for Industrial Exhaust Processing
$26,000.00
ASY Gravure Printing Machine for Plastic Film, 6-Color Flexographic Printer for Shopping Bags
$86,400.00
Coil Refractory Cement for Medium-Frequency Furnace Repair - Fine High-Temperature Bonding Agent for Copper Coils (White/Red)
$7,800.00
Over-Toilet Storage Rack - No-Drill Bathroom Organizer Shelf for Restrooms and Washrooms, Space-Saving Storage Solution
$8.90
NIU NXT Instrument Cover for FXT/FX Electric Scooters – Waterproof Protective Case and Modification Accessory
$6.50
Anlin FK1 Cheyenne Tattoo Pen Silent Model All-in-One for Lining and Shading
$221.25
![[Osstem Dental Implants] Imported Dental Crowns and Bridges by Aizhier Oral Care for Partial Tooth Loss](https://www.gosteppe.com/cache/small/product/269993/legacy-main-02952134e1556f7660e1525f.webp)
[Osstem Dental Implants] Imported Dental Crowns and Bridges by Aizhier Oral Care for Partial Tooth Loss
$230.00
Heavy-Duty Multi-Layer Warehouse Shelving Unit for Storage, Retail, and Home Use
$252.00
Rattle Car Teether Wooden Bead Educational Soothing Teething Set Baby Photo Prop
$15.00
Roast Duck and BBQ Warmer Cabinet - Constant Temperature Heating Display Case for Crispy Pork Belly and Hanging Ducks
$710.00
Traditional Handmade Baby Rattle with Chewable Sheepskin for Newborns
$12.50
5pcs Lily tubular length 7cm fish tank aquarium glass
$9.90
Data Cable Interface Safety Case for iPhone, Apple, and Android Charging Cables - Child and Pet Proof
$16.80
Commercial Roast Duck Warmer Cabinet Constant Temperature Food Heater Display Counter for Cooked Meat
$1,494.00
Over-Toilet Storage Rack - Multi-Layer Bathroom Organizer with No-Drill Installation for Tank and Supplies
$17.92
Natural 7A White Azeztulite Loose Beads for DIY Handmade Bracelets, Spacer Beads, Multi-Gem Jewelry Accessories
$2.07
Hanyue Cordura N66 Rafting Bag Outdoor Swimming Trekking Clothes Storage Ultra-Light Waterproof Dry Bag
$35.70
Electromagnetic Planetary Stir-Fry Pot Sugar Fillings Pre-made Dish Cooking Equipment Tomato Sauce Chili Sauce Stir-Fry Machine
$3,940.00
Factory Direct 6L Stainless Steel Round Buffet Warmer - Electric Heating with Flip-Top Lid for Hotel and Restaurant Use
$764.00
Polishing Workshop Grinding Platform Plasma Cutting Welding Fume Dust Removal Environmental Equipment 3000 Airflow Grinding Platform
$6,000.00
Tongyue Food Warmer Cabinet - Large Capacity Home Kitchen Hot Dish Heater for Autumn and Winter
$607.20
Taikang Bybo Dental - Swiss Straumann ITI Dental Implants with Metal Abutments (TK)
$20,000.00
Marie's Sketching Blending Stump Set for Artists - Highlight, Shadow, and Detail Tools with Silicone Tips and Sponge Blenders
$15.30
Bottled Water Stand – Inverted Rack with Pump Dispenser for Large Mineral/Pure Water Jugs
$18.50
Sketching Blending Stump Set - Fine & Round Tip Tools with Replaceable Sponge Heads for Highlight Creation, Drawing Correction, and Tracing
$7.26
Automatic Retractable Air Hose Reel Auto Repair Car Wash Shop Electric Reel Water Drum PU Air Pipe Sandblasting Hose
$72.20
![[Live Stream Exclusive] Taikang Bybo Dental - South Korean Dentium Dental Implants for Tooth Loss Restoration](https://www.gosteppe.com/cache/small/product/269973/legacy-main-5e274b6981a80a22f7dc25a6.webp)
[Live Stream Exclusive] Taikang Bybo Dental - South Korean Dentium Dental Implants for Tooth Loss Restoration
$2,480.00
![[Trial Pack] Xianlang Complete Cat Treat Sticks Meal Packs Main Course Cans Freeze-Dried Cat Food Sample Snacks Gift Set](https://www.gosteppe.com/cache/medium/product/208273/legacy-main-9ec245ebf781f65a434ba854.webp)
