MQ-4 Methane Gas Sensor

  The MQ-4 gas sensor uses tin oxide (SnO₂) as its sensing material, which has a low conductivity in clean air. When combustible gases are present in the environment, the conductivity of the sensor increases with the concentration of these gases in the air. A simple circuit can convert this change in conductivity into an output signal corresponding to the concentration of the gas. The MQ-4 sensor is highly sensitive to methane and also responds well to propane and butane. This sensor is capable of detecting various combustible gases, particularly natural gas, making it a low-cost solution suitable for a wide range of applications.

Module Source

Purchase Link: https://detail.tmall.com/item.htm?abbucket=0&id=696222346171&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
DO (Digital Output): Digital signal output AO (Analog Output): Analog signal output Reading Method: ADC (Analog-to-Digital Converter)
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
  * Modified By: www.lckfb.com
  * Modification Date: April 8, 2024
  * Function Overview:
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int MQ4_AO_Pin = A0; // 定义甲烷传感器的AO连接到开发板的A0引脚
int MQ4_DO_Pin = 8;  // 定义甲烷传感器的DO连接到开发板的8号引脚
int MQ4Value = 0; // 用于存储甲烷浓度值的变量
#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(MQ4_DO_Pin, INPUT_PULLUP);
}

void loop() {
  // 读取状态
  int MQ4State = digitalRead(MQ4_DO_Pin);
  if (MQ4State == LOW) {
    Serial.println("检测到甲烷");
  } else {
    Serial.println("未检测到甲烷");
  }

  MQ4Value = analogRead(MQ4_AO_Pin); // 读取A0引脚的电压值
  Serial.print("甲烷浓度: ");
  Serial.println( MQ4Value); // 将读取的值发送到电脑的串行监视器
  delay(1000); // 延时1秒
}

Usage Testing