Interface Gas Sensor With Arduino Uno

A Gas detector is a device that detects the presence of gases in an area.

  • Gas sensors spontaneously react to the gas present .
  • These sensors usually employ an audible alarm to alert people when a dangerous gas has been detected.
  • Different types of gas sensor available in market like MQ2, MQ3, MQ4, MQ5, MQ6, MQ7, MQ8, MQ9.
  • Each type have unique characteristics to detect the gas.
  • Sensitive material of gas sensor is SnO2 which have lower conductivity in clean air..
  • When the target flammable gas exist, the sensor conductivity gets higher along with the gas concentration rising.
  • Gas sensor can detect different kinds of flammable gases,especially has high sensitivity to LPG (propane).


  • Domestic gas leakage alarm.
  • Industrial flammable gas alarm.
  • Portable gas detector.

Hardware Required

  • Gas Sensor.
  • Arduino.

Pin Diagram

  • VCC: +5v.
  • A0: Analog Output.
  • GND: GND.



 int gasPin = A0;
 int gasValue = 0;
 void setup()
 void  loop()
 gasValue = analogRead(gasPin);
 if(gasValue >500);