35 lines
668 B
C++
35 lines
668 B
C++
#include <Arduino.h>
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#define analogMQ7 33
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#define digitalMQ7 32
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float sensor_volt;
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float RS_air;
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float R0;
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float sensorValue;
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void MQ7_init(){
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pinMode(digitalMQ7, INPUT);
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pinMode(analogMQ7, INPUT);
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}
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void MQ7_read()
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{
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analogWrite(analogMQ7, 1023);
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delay(60000);
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analogWrite(analogMQ7, (1023/5)*1.4 );
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for(int i = 0; i<100; i++){
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sensorValue = sensorValue + analogRead(analogMQ7);
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delay(90000);
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}
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sensorValue = sensorValue/100.0;
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sensor_volt = sensorValue/1024*5.0;
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RS_air = (5.0-sensor_volt)/sensor_volt;
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R0 = RS_air/(26+(1/3));
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Serial.print("R0 = ");
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Serial.println(R0);
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delay(1000);
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} |