8A1 MQ-2 Smoke methane Gas LPG Butane Hydrogen Gas Sensor Detector Module

What is an MQ2 Gas Sensor? 

MQ2 sensor is a gas sensor having high sensitivity to LPG, propane, hydrogen, methane and other combustible steam. 

The SnO2 semiconductor material is used in the MQ2 for detecting the gases. It has lower conductivity in clean air. It helps in detecting the rising levels of gases through rise in its conductivity. Users can convert the change of conductivity to gas concentration through a simple electronic circuit.

Datasheet

An MQ2 gas sensor has a wide array of applications such as:

• Domestic gas leakage detector
• Portable gas leakage detector
• Industrial Combustible gas detector

The applicability of an MQ2 gas sensor is enhanced by the following features:

• Good sensitivity to a wide range of combustible gas
• High sensitivity to LPG, Propane and Hydrogen
• Simple drive circuit
• Long life
• Low cost 

MQ2 Gas Sensor specifications

• Operating Voltage: 5V 
• Operating Current: 150mA
• Concentration: 300-10000ppm

MQ2 Gas Sensor pin diagram

Pin1: It is VCC Pin. It is used to connect 5V to the sensor.
Pin2: It is GND Pin. It is used to connect GND to the sensor.
Pin3: It is analog output Pin. From this pin you will get analog data.
Pin4: It is digital output Pin. From this pin you will get digital data HIGH/LOW.

Circuit diagram of MQ2 Gas Sensor with Arduino

Pin connection of MQ2 Gas Sensor with Arduino

• Connect the VCC pin of the sensor to the 5V pin of the Arduino UNO board
• Connect the GND pin of the sensor to the GND pin of the Arduino UNO board
• Connect the AO pin of the sensor to the A3 pin of the Arduino UNO board

Arduino code for interfacing MQ2 Gas Sensor with Arduino

int sensorPin=A4;
int sensorData;
void setup()
{  
  Serial.begin(9600);   
  pinMode(sensorPin,INPUT);                         
 }
void loop()
{
  sensorData = analogRead(sensorPin);       
  Serial.print("Sensor Data:");

  delay(100);                                   
}

Arduino code working

Create a variable named sensorPin to the pin number of the Arduino UNO board where you have connected the AO pin of the sensor. In our case, it is A3 pin of the Arduino UNO board.

Create another variable named sensorData. We will use this variable to store the data that will be received by the Arduino from the sensor.

Inside the void setup block, set the baud rate for the serial communication and initiate the serial communication using Serial.begin() command.

Then use the pinMode() function to set the sensorPin as INPUT. The Arduino will use this pin to get the analog data from the sensor.

Inside the void loop() function, use sensorData variable to store the data that is received by the Arduino from the sensor. 

Then, print the data on the serial monitor using the print and println command.

Note: The sensor can detect LPG, propane, hydrogen, methane and other combustible steam. So, the value that you will get from the sensor will depend on the gas that is present.