Arduino MQ-2 Gas Sensor example

The MQ-2 is a fairly low cost sensor that can detect  LPG, i-butane, propane, methane ,alcohol, Hydrogen, smoke. There are a wide variety of shields and modules that can be bought and connected to your Arduino

You can see the sensor in the image below

VCC – 5V
GND – GND
AOUT – Analog pin 0

gas sensor

Code

[codesyntax lang=”cpp”]

const int analogInPin = 0;
 
int sensorValue = 0;
int count1;
 
void setup() 
{
  Serial.begin(9600); 
}
 
void loop() 
{
 
  count1++;
  // read the analog in value:
  sensorValue = analogRead(analogInPin);            
 
  if(count1==3000)
  {
    count1=0;
 
   Serial.println(sensorValue, DEC);  // prints the value read
  }
}

[/codesyntax]

When this run, open up the serial monitor and you should see something like the following

mq2 output

Link

You can pick up one of these modules from between $3 to $5

KEYES DIY 3 pin MQ2 Smoke Gas Sensor Module for Arduino with Connection Cable Red

SainSmart MQ2 Gas Sensor Module For LPG Propane Hydrogen Arduino Compatible