MQ-2 sensor does not detect smoke

I have an MQ-2 sensor connected to Arduino Nano and i read values with analog A0 pin.

Arduino 5V goes to the VCC pin and the Arduino Ground to the GND pin on the sensor.

When i hold an butan torch under it i can se the values in serial monitor changes from around 100 to 5-600.

But it does not seams to detect smoke from for example my solder iron. (solder fume). It does not detect smoke from burned wire isolation either.

Is it something i doing wrong?

No. Its not a smoke detector, its a gas detector. Smoke is not gas.


And that is the first and last time they mention smoke apart from a graph.
Can you please post a circuit diagram of your project?

Did you try smoke from a match like in the video.
Along with that smoke would be all sorts of burning products.

Tom… :grinning: :+1: :coffee: :australia:

But what is smoke? Its any particulate matter dispersed in the air, could be soot,
sooty wax particles, condensed flux vapours, metal oxides, anything really - the way you
detect smoke is optically by scattering of light, not but a surface-sensing gas detector (which may be sensitive to some kinds of smoke, but its not likely to be reliable as there
are so many kinds of smoke).