I was interested in making a smoke detection unit which starts taking a video and also sends an SMS once the detector detects smoke; the problem is, which smoke detector should I use? Also, how do I connect and program this? I'm thinking of using B+ and using an MQ-2 sensor, should I also use an Arduino for this?

  • 1
    I've used MQ sensors with the Pi. You'll need an analog-to-digital converter chip like the MCP3008. Fairly easy. Take a look at raspberrypi-spy.co.uk/2013/10/…
    – recantha
    Dec 19, 2014 at 14:52
  • 1
    @recantha, Can I use this guide? learningaboutelectronics.com/Articles/… it seems simple and my question is if I could use it with raspberry pi B+ and another sensor.. Dec 19, 2014 at 22:22
  • 1
    @HayzamSherif Yes, that guide will do nicely. The B+ is pin compatible with the B, so will work. The analog to digital chip is smaller than the one I suggested but will work just as well. :-)
    – recantha
    Dec 20, 2014 at 7:02
  • 1
    One more question @recantha, In the guide they use a 3 pin sensor(Output VCC and GND), I want to use a 4 pin sensor(VCC, AO, DO, GND) this one : amazon.com/MQ-135-Quality-Hazardous-Detection-Arduino/dp/… and its MQ-135 so which analog should I use? Does the analog depend on the model of the sensor I use? Dec 20, 2014 at 8:27
  • 2
    Anywhere you like, honestly :-) Plug it into the breadboard horizontally so the pins aren't connected to each other then connect up your 5V and GND pins from your Pi to the relevant columns on the breadboard. Then connect an analog input pin from the chip to the analog output of the sensor
    – recantha
    Jan 21, 2015 at 18:23

1 Answer 1


just use FC-22 type MQ2 sensor. It has both Digital and Analog output. For a precise measurement you can do analog-digital conversion using MCP3008, But to keep things simple you can just use the digital pin to detect if there is smoke. You can also set the sensor sensitivity by a variable resistor on the sensor.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.