کد:
#include<string.h>
byte buff[2];
int pin = 8;//DSM501A input D8
unsigned long duration;
unsigned long starttime;
unsigned long endtime;
unsigned long sampletime_ms = 30000;
unsigned long lowpulseoccupancy = 0;
float ratio = 0;
float concentration = 0;
int i=0;
void setup()
{
Serial.begin(9600);
pinMode(8,INPUT);
starttime = millis();
}
void loop()
{
duration = pulseIn(pin, LOW);
lowpulseoccupancy += duration;
endtime = millis();
if ((endtime-starttime) > sampletime_ms)
{
ratio = (lowpulseoccupancy-endtime+starttime + sampletime_ms)/(sampletime_ms*10.0); // Integer percentage 0=>100
concentration = 1.1*pow(ratio,3)-3.8*pow(ratio,2)+520*ratio+0.62; // using spec sheet curve
Serial.print("lowpulseoccupancy:");
Serial.print(lowpulseoccupancy);
Serial.print("\n");
Serial.print("ratio:");
Serial.print("\n");
Serial.print(ratio);
Serial.print("DSM501A:");
Serial.println(concentration);
Serial.print(";\n\n");
lowpulseoccupancy = 0;
starttime = millis();
}
مرجع: