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36 lines
1.0 KiB
36 lines
1.0 KiB
#include <math.h>
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int DustSensePin = 13;
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unsigned long duration;
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unsigned long starttime;
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unsigned long sampletime_ms = 30000;//sample 30s ;
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unsigned long lowpulseoccupancy = 0;
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float ratio = 0;
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float concentration = 0;
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void setup()
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{
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Serial.begin(9600);
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Serial.println("Starting Air Sensor, please wait for readings...");
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pinMode(DustSensePin,INPUT);
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starttime = millis();//get the current time;
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}
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void loop()
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{
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duration = pulseIn(DustSensePin, LOW);
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lowpulseoccupancy = lowpulseoccupancy+duration;
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if ((millis()-starttime) > sampletime_ms)//if the sample time == 30s
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{
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ratio = lowpulseoccupancy/(sampletime_ms*10.0); // Integer percentage 0=>100
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concentration = 1.1*powf(ratio,3)-3.8*powf(ratio,2)+520*ratio+0.62; // using spec sheet curve
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Serial.print(lowpulseoccupancy);
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Serial.print(",");
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Serial.print(ratio);
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Serial.print(",");
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Serial.println(concentration);
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lowpulseoccupancy = 0;
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starttime = millis();
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}
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}
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