Phantom YoYo Arduino compatible Mini MQ4 Gas Sensor

This ones a no brainer if you don't require actual ppm readings. You'd have to calibrate for that numerically. But if you just need to sense quantity "small, some, more, lots, danger!" Then this is EASY. This particular gas sensor picks up CNG best, but also propane and butane. You can use an unlit cigarette lighter puff to sense gas. Sensed values rise REAL quickly. Very sensitive. For just a quick reading, I just turn on the heater (VCC +5V) and wait for the values to go to the bottom (No gas). If they don't. Then there must be gas. It took mine about 40 secs to settle. It uses 150ma of current for the heater, so I advise a MOSFET. Keeping it on will provide a high level of accuracy since this is how it was designed. Yes. A heater. It gets warm, maybe hot. I heard tale of someone with a bad unit tuning red hot before it died. He burnt his fingie.

This sensor works well and has a high sensitivity.I've tested it with the standard Arduino Uno, a SainSmart Nano, and an Adafruit Trinket Pro.There are no special libraries to download, simply provide a 5V reference to the VCC pin, a ground to the ground, and tie the out to one of the analog pins on the 'duino.

Seems to work alright however I cannot find much information on it. All of the online documentation says the Q4 has 4 pins but mine has a 3 pin configuration. The lack of included instructions and inconsistency with online info is the only reason I rate this 3 stars. The values I get vary wildly as well, but I think that may be partly due to my own incompetence.

It actually works in Raspberry Pi3 using available python code. I believe I also saw C and C+ code for this on GitHub.

This component arrived in reasonable time and was functional after configuring it with my Arduino. The MQ4 is designed to detect combustibles, and was able to detect the ignition of a lighter within close proximity. Very pleased with this MQ4 sensor.