Hello,

In this tutorial, we are going to learn how to make a breathalyzer using Arduino.

Hardware Required

Software Required

MQ3 Sensor

  • The MQ3 sensor works on the same principle as the MQ2 smoke sensor. It has a sensing element with six terminals, four output, and two heating terminals. 
  • It has 4 pins. 
  • VCC for power supply. 
  • GND for ground. 
  • DO for digital output. 
  • AO for analog output. 

Circuit Diagram

Pins on MQ3 Sensor

Pins on Arduino Mega

VCC

5V

GND

GND

AO

A0

Pins on OLED

Pins on Arduino Mega

VCC

5V

GND

GND

SDA

SDA

SCL

SCL

Working Concept

 

  • The working concept of this project consists of three components: Arduino board, MQ3 sensor, and the LCD Display.
  • First comes the sensing part. Here MQ3 alcohol sensor will sense the amount of alcohol in someone's breath. It then converts this data into output voltage which tells the concentration of the alcohol present.
  • These output signals are sent to the Arduino board. 
  • The Arduino board then converts these signals into suitable signals for the OLED Display and sends them to them via I2C communication.
  • The OLED Display shows the alcohol level to the user. 

Arduino Code

 

  • Upload the code. Perform the circuit diagram. 

Now your breathalyzer is ready for use.