MQ - 2 Gas Sensor Brick

Overview

The electronic brick of gas sensor can be used in fire protection systems to detect hydrogen, isobutane, liquefied petroleum gas, methane, carbon monoxide, alcohol, smoke, propane and other harmful gases.

Features

1. Plug and play, easy to use. Compatible with the mainstream 2.54 interfaces and 4-Pin Grove interfaces in the market.

2. With use of M4 standard fixed holes, compatible with M4-standard kits such as Lego and Makeblock.

Specifications

PCB size	33.0mm X 14.0mm X 1.6mm
Working voltage	5V DC
Operating voltage	5V DC
Compatible interfaces	2.54 3-pin interface and 4-pin Grove interface(1)

Note 1: S for analog output port, V and G for voltage at the common collector and ground respectively

Electrical Characteristics

Parameter	Min.	Typical	Max.	Unit
Working voltage	4.5	5	5.5	VDC
Analog output voltage（VCC=5V）	0	-	5	V
Working current（VCC=5V）	-	122	-	mA

The sensitive characteristics of MQ-2 to various gases

Demo

Connect S port of electronic brick of gas sensor to A0 port of Arduino board, and we will use the following program to read the analog value. When the analog value exceeds the threshold, LED lamp will flash.

 const int ledPin =  13;      // the number of the LED pin
 const int thresholdvalue=400; //The threshold to turn the led on
 void setup() {
    pinMode(ledPin, OUTPUT); 
 }
 void loop() {
 int sensorValue = analogRead(A0); //use A0 to read the electrical signal
 if(sensorValue>thresholdvalue)
 digitalWrite(ledPin,HIGH); //if the value read from A0 is larger than 400,then light the LED
 delay(200);
 digitalWrite(ledPin,LOW);
 }