How to use the MQ3 Alcohol Sensor for Arduino

INTRODUCTION

The MQ3 Alcohol Gas Sensor is a low cost semiconductor sensor which can detect the presence of alcohol gases at concentrations from 0.05 mg/L to 10 mg/L. The sensitive material used for this sensor is SnO2 (Tin Oxide) which conductivity is lower in clean air.

APPLICATIONS

The alcohol sensor is suitable for detecting alcohol concentration in your breath, just like your common breathalyzer.

WIRING DIAGRAM

VCC – 5V

AOUT – Analog Pin A0

DOUT – Digital Pin 5

GND – GND

 

CODE

int analogsensor = A0;

void setup() {
  // put your setup code here, to run once:

pinMode(analogsensor, OUTPUT);
Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
int inputdigital = digitalRead(digitalsensor);
int inputanalog = analogRead(analogsensor);

Serial.println(inputanalog);

delay(100);
}

END RESULT

Open serial monitor and place some alcohol in front of the sensor, rubbing alcohol will do just fine. The numbers displayed on the serial monitor should increase with the presence of alcohol.

ADDITIONAL RESOURCES

http://www.learningaboutelectronics.com/Articles/MQ-3-alcohol-sensor-circuit-with-arduino.php

https://www.elprocus.com/mq-135-alcohol-sensor-circuit-and-working/