This is using the MQ-2 sensor to detect methane using Photon. The idea is to control variables over wifi so it can use IFTTT to send you messages or emails when it detects gas leakage... Or farts.

This is using the MQ-2 sensor to detect methane using Photon. The idea is to control variables over wifi so it can use IFTTT to send you messages or emails when it detects gas leakage... Or farts.

 

When using the MQ-2 without a brick or breakout board, you must solder wires to each pin - the two middle pins are the heater coil pins, and must go to a positive rail and negative rail, respectively. The two pins by the side of either middle pins are "A" pins and the other two are "B" pins. A pins must be connected togheter as well as B, but you must choose which one will be the load resistance (the one you're going to read throught the analog pins of Arduino or Photon boards).

 

Bear in mind that the load resistance, according to the MQ-2 datasheet (check the link) must have a 20K resistance - but since the Photon receives only 3.3V on each pin, I had to calculate the resistance to be around 4.7K.

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guzforster 3 years, 4 months ago

This is actually the MQ-3 sensor (it detects alcohol), but the connections are exactly the same as any MQ-X sensor.