Arduino MQ135气体感应器
一、接线
MQ135有4个引脚，分别为VCC、GND、A0、D0,这里只需要使用到VCC、GND、A0.以下图是esp8266接线图。由于测量气体值PPM时，跟空气的温湿度是相关的。所以我们这里加了一个DHT22。DHT22传送门
VCC->3V
GND->G
A0->A0
二、MQ135库
下载地址：https://github.com/zhao007z4/MQ135
下载完成后，拷贝到arduino库目录下
三、代码
#define DHT_TYPE DHT11
#define DHT_PIN 2 //pin d4
#define ANALOGPIN A0
DHT dht(DHT_PIN, DHT_TYPE);
MQ135 gasSensor = MQ135(ANALOGPIN);
void setup() {
Serial.begin(9600);
dht.begin();
}
void loop() {float h = dht.readHumidity();
// Read temperature as Celsius (the default)
float t = dht.readTemperature();
// Check if any reads failed and exit early (to try again).
if (isnan(h) || isnan(t))
{
Serial.println("Failed to read from DHT sensor!");
delay(1000);
return;
}
Serial.print("hum=");
Serial.print(h); // this to display the rzero value continuously, uncomment this to get ppm value
Serial.println("%");
Serial.print("temp=");
Serial.print(t); // this to display the rzero value continuously, uncomment this to get ppm value
Serial.println("C");
rzero = gasSensor.getRZero(); //this to get the rzero value, uncomment this to get ppm value
Serial.print("RZero=");
Serial.println(rzero); // this to display the rzero value continuously, uncomment this to get ppm value
ppm = gasSensor.getPPM(); // this to get ppm value, uncomment this to get rzero value
Serial.print("PPM=");
Serial.println(ppm); // this to display the ppm value continuously, uncomment this to get rzero value
ppmbalanced = gasSensor.getCorrectedPPM(t, h); // this to get ppm value, uncomment this to get rzero value
Serial.print("PPM Corrected=");
Serial.println(ppmbalanced); // this to display the ppm value continuously, uncomment this to get rzero value
}
四、总结
从MQ135文档中，我们了解到，MQ135要正常工作，需要预热不少于48小时。中文文档传送门