1-4 MQ-9

一、元件介紹

感測：一氧化碳，可燃氣體

Arduino UNO	MQ-9 元件
A0	A0
不接	D0
GND	GND
5V	VCC

 

二、接線範例

 

三、程式範例

Arduino程式參考：http://wiki.seeed.cc/Grove-Gas_Sensor-MQ9/

基礎

void setup() {
    Serial.begin(9600);
}

void loop() {
    float sensor_volt;
    float sensorValue;

    sensorValue = analogRead(A0);
    sensor_volt = sensorValue/1024*5.0;

    Serial.print("sensor_volt = ");
    Serial.print(sensor_volt);
    Serial.println("V");
    delay(1000);
}

 

測量近似值

1. Keep the Gas Sensor in clean air environment. Upload the program below.

   void setup() {
       Serial.begin(9600);
   }
   
   void loop() {
       float sensor_volt;
       float RS_air; //  Get the value of RS via in a clear air
       float R0;  // Get the value of R0 via in LPG
       float sensorValue;
   
       /*--- Get a average data by testing 100 times ---*/
       for(int x = 0 ; x < 100 ; x++)
       {
           sensorValue = sensorValue + analogRead(A0);
       }
       sensorValue = sensorValue/100.0;
       /*-----------------------------------------------*/
   
       sensor_volt = sensorValue/1024*5.0;
       RS_air = (5.0-sensor_volt)/sensor_volt; // omit *RL
       R0 = RS_air/9.9; // The ratio of RS/R0 is 9.9 in LPG gas from Graph (Found using WebPlotDigitizer)
   
       Serial.print("sensor_volt = ");
       Serial.print(sensor_volt);
       Serial.println("V");
   
       Serial.print("R0 = ");
       Serial.println(R0);
       delay(1000);
   
   }

    

2. Replace the R0 below with value of R0 tested above . Expose the sensor to any one of the gas listed above.

   void setup() {
       Serial.begin(9600);
   }
   
   void loop() {
   
       float sensor_volt;
       float RS_gas; // Get value of RS in a GAS
       float ratio; // Get ratio RS_GAS/RS_air
       int sensorValue = analogRead(A0);
       sensor_volt=(float)sensorValue/1024*5.0;
       RS_gas = (5.0-sensor_volt)/sensor_volt; // omit *RL
   
             /*-Replace the name "R0" with the value of R0 in the demo of First Test -*/
       ratio = RS_gas/R0;  // ratio = RS/R0
             /*-----------------------------------------------------------------------*/
   
       Serial.print("sensor_volt = ");
       Serial.println(sensor_volt);
       Serial.print("RS_ratio = ");
       Serial.println(RS_gas);
       Serial.print("Rs/R0 = ");
       Serial.println(ratio);
   
       Serial.print("\n\n");
   
       delay(1000);
   
   }

    

其他程式參考：https://www.elecrow.com/wiki/index.php?title=Analog_CO/Combustible_Gas_Sensor(MQ9)