termo_comm

#include <wiringPi.h>
#include <stdio.h>
#include <math.h>

//Declara a porta 7 como o PWM
#define PWM    7
#define LAMP   2
#define TE     3
#define CONT   5000000

int main (void) {

  int high=0, low=0, read=0, i;
  float resistance=0, temperature=0, vref = 0;
  float (dutyCycle);

  printf("\n");
  printf("Leitura da temperatura através do RasPi\n\n");

  wiringPiSetup ();
  //Configura a porta 7 como entrada
  pinMode(PWM, INPUT);
  pinMode(LAMP, OUTPUT);
  pinMode(TE, OUTPUT);

  for(;;) {
    for (i=0; i<CONT; i++) {

      read = digitalRead(PWM);

      if(read){
        high++;
      }

      else {
        low++;
      }

    }

    dutyCycle = (float)high/(high+low);
    high = 0;
    low = 0;
    vref = 5.0*dutyCycle;
    resistance = (float)(1936*vref)/(5-vref);
    temperature = -log(resistance/6883)/0.03774;

    printf("Tensão de Referência: %0.2f V\n", vref);
    printf("Duty Cycle: %0.2f %\n", 100*dutyCycle);
    printf("Temperatura: %0.2f ºC\n", temperature);
    printf("\n");

    if (temperature > 43) {
      digitalWrite(LAMP, LOW);
      delay(50);
      digitalWrite(TE, LOW);
      delay(50);
      digitalWrite(TE, HIGH);
    }

    else if (temperature < 42) {
      digitalWrite(LAMP, HIGH);
      delay(50);
      digitalWrite(TE, LOW);
      delay(50);
      digitalWrite(TE, HIGH);
    }

  }

  return 0;

}