MQ-2 Gas / Smoke Sensor
by Winsen / generic
SKU: PSA-CMP-MQ2
No reviews yetTypical India street price
₹70–₹140
Tin-dioxide sensor for LPG, smoke, methane classroom demos.
Interface: Analog + digital
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Concept
A heated metal-oxide surface changes resistance in the presence of combustible gas.
A little theory
SnO2 at ~300 °C: reducing gases lower resistance. Not a calibrated ppm meter without curve fitting and fresh air baseline. In the classroom, treat MQ-2 Gas / Smoke Sensor as a intermediate part using Analog + digital. Typical India street price is about ₹70–₹140. Always verify voltage and pin labels on your exact module — silk screens vary across clones. Start with a datasheet or trusted learn guide, power the part correctly, share GND with the MCU, and test with a simple blink/read sketch before building the full project. Measure voltages with a multimeter when something fails, and keep actuator current off the MCU regulator.
How it works in a project
Preheat several minutes. Read AO; DO trips a pot threshold. Map AO to a “relative smoke” number for labs.
Classroom & project use
- Smoke alarm demo
- Kitchen LPG alert (demo only)
- Sensors classroom demo
Buying in India
Precautions
- Heater gets hot
- Not a certified smoke alarm
- Use in a ventilated lab
Specifications
| Gases | LPG, smoke, H2, CO (cross-sensitive) |
| Heater | 5V |
| Category | Sensors |
| Difficulty | Intermediate |
| Voltage | 5V |
| Interface | Analog + digital |
Pinout
VCC | GND | AO (and DO if comparator module)
