Smoke detection using MQ-2 gas sensor

 

AIM: a. To  interface MQ-2 Gas sensor to Arduino board

APPARATUS: 1. Arduino Uno Board – 1 No.

                           2. LED - 1No.

                           3. Resistor-100 Ohm -1 No.

                           4. Bread Board – 1 No.

                           5. Connecting Wires

                           6. USB Cable.

                           7. MQ-2 Gas Sensor -1No.

THEORY:

The MQ series of gas sensors use a small heater inside with an electro-chemical sensor. They are sensitive for a range of gasses and are used indoors at room temperature. The output is an analog signal and can be read with an analog input of the Arduino.

The MQ-2 Gas Sensor module is useful for gas leakage detecting in home and industry. It can detect LPG, i-butane, propane, methane ,alcohol, hydrogen and smoke.

Some modules have a built-in variable resistor to adjust the sensitivity of the sensor.

Note: The sensor becomes very hot after a while, don't touch it!

In this tutorial we will use the serial monitor of Codebender (or Arduino IDE) to see how the sensor acts in variable gasses.

The connections are pretty easy:

• Vcc to Arduino 5V pin

• GNG to Arduino GND pin

• Output to Arduino Analog A0 pin

Note: The sensor becomes very hot after a while, don't touch it!

So, let's get started!

  

PROGRAM:

const int gasPin = A0; //GAS sensor output pin to Arduino analog A0 pin

void setup()

{

Serial.begin(9600); //Initialize serial port - 9600 bps

}

void loop()

{

Serial.println(analogRead(gasPin));

delay(1000); // Print value every 1 sec.

}