MQ-3 Alcohol Sensor

  The MQ-3 gas sensor uses tin dioxide (SnO₂) as the sensing material, which has low conductivity in clean air. When alcohol vapor is present in the environment, the sensor's conductivity increases with the concentration of alcohol vapor in the air. A simple circuit can convert this change in conductivity into an output signal that corresponds to the concentration of alcohol. The MQ-3 sensor is commonly used for alcohol detection in breathalyzers and other applications involving air quality monitoring, making it an essential tool for safety and environmental monitoring systems.

Module Source

Purchase Link:
https://detail.tmall.com/item.htm?abbucket=0&id=695089814069&ns=1&spm=a21n57.1.0.0.5668523c1NVcMb
Baidu Netdisk Download Link:
https://pan.baidu.com/s/1B8WhPIzTmWwQsFFVayRpAA?pwd=9966
Password: 9966

Specifications

Operating Voltage: 3.3V-5V
Operating Current: 150MA
Output Type:
DO (Digital Output): Digital signal output AO (Analog Output): Analog signal output Reading Method: ADC (Analog-to-Digital Converter)
Pin Count: 4 Pins (2.54mm pitch header)

Hardware Connection

• Connect the Vcc pin of the sensor to the 5V power supply of the development board.
• Connect the GND pin of the sensor to the GND of the development board.
• Connect the AO (Analog Output) pin to the A0 analog input pin of the development board.
• Connect the DO (Digital Output) pin to the digital pin 8 of the development board.

Usage Method

/******************************************************************************
  * Test Hardware: LCSC ColorEasyDuino Development Board
  * Version Number: V1.0
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  * Modification Date: April 8, 2024
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int MQ2_AO_Pin = A0; // 定义烟雾电阻传感器的AO连接到开发板的A0引脚
int MQ2_DO_Pin = 8;  // 定义烟雾传感器的DO连接到开发板的8号引脚
int MQ2Value = 0; // 用于存储烟雾浓度值的变量
#define ADC_MAX_VALUE 1023  //ADC的最大采集值

void setup() {
  Serial.begin(9600); // 开始串行通讯，设置波特率为9600
  pinMode(MQ2_DO_Pin, INPUT_PULLUP);
}

void loop() {
  // 读取按钮的状态
  int MQ2State = digitalRead(MQ2_DO_Pin);
  if (MQ2State == LOW) {
    Serial.println("检测到高浓度烟雾");
  } else {
    Serial.println("检测到低浓度烟雾");
  }

  MQ2Value = analogRead(MQ2_AO_Pin); // 读取A0引脚的电压值
  Serial.print("烟雾浓度: ");
  Serial.println( MQ2Value); // 将读取的值发送到电脑的串行监视器
  delay(1000); // 延时1秒
}

Usage Testing