DHT11 - Temperatura ed umidità

      /*Librerie:
            dht11.cpp VER.0.4.1
            dht11.h   VER 0.4.1 */
            
        
      #include <dht11.h>
     
      #define SensoreDHT11 2
     
      dht11 ValoreDHT11;
       
      void setup()
          {Serial.begin(9600);   }
      
      void loop(){
        
           Serial.println("\n");
      
           ValoreDHT11.read(SensoreDHT11);
                             
      
           float h =ValoreDHT11.humidity;
               Serial.print("Humidity (%): ");
               Serial.println(h);
      
           float t =ValoreDHT11.temperature;
               Serial.print("Temperature (C): ");
               Serial.println(t);
           
        delay(2000);
      }
  

// FILE: dht11.cpp
// VERSION: 0.4.1
// PURPOSE: DHT11 Temperature & Humidity Sensor library for Arduino
// LICENSE: GPL v3 (http://www.gnu.org/licenses/gpl.html)
//
// DATASHEET: http://www.micro4you.com/files/sensor/DHT11.pdf
//
// HISTORY:
// George Hadjikyriacou - Original version (??)
// Mod by SimKard - Version 0.2 (24/11/2010)
// Mod by Rob Tillaart - Version 0.3 (28/03/2011)
// + added comments
// + removed all non DHT11 specific code
// + added references
// Mod by Rob Tillaart - Version 0.4 (17/03/2012)
// + added 1.0 support
// Mod by Rob Tillaart - Version 0.4.1 (19/05/2012)
// + added error codes
//

#include "dht11.h"

// Return values:
// DHTLIB_OK
// DHTLIB_ERROR_CHECKSUM
// DHTLIB_ERROR_TIMEOUT
int dht11::read(int pin)
{
// BUFFER TO RECEIVE
uint8_t bits[5];
uint8_t cnt = 7;
uint8_t idx = 0;

// EMPTY BUFFER
for (int i=0; i< 5; i++) bits[i] = 0; // REQUEST SAMPLE pinMode(pin, OUTPUT); digitalWrite(pin, LOW); delay(18); digitalWrite(pin, HIGH); delayMicroseconds(40); pinMode(pin, INPUT); // ACKNOWLEDGE or TIMEOUT unsigned int loopCnt = 10000; while(digitalRead(pin) == LOW) if (loopCnt-- == 0) return DHTLIB_ERROR_TIMEOUT; loopCnt = 10000; while(digitalRead(pin) == HIGH) if (loopCnt-- == 0) return DHTLIB_ERROR_TIMEOUT; // READ OUTPUT - 40 BITS => 5 BYTES or TIMEOUT
for (int i=0; i<40; i++) { loopCnt = 10000; while(digitalRead(pin) == LOW) if (loopCnt-- == 0) return DHTLIB_ERROR_TIMEOUT; unsigned long t = micros(); loopCnt = 10000; while(digitalRead(pin) == HIGH) if (loopCnt-- == 0) return DHTLIB_ERROR_TIMEOUT; if ((micros() - t) > 40) bits[idx] |= (1 << cnt); if (cnt == 0) // next byte? { cnt = 7; // restart at MSB idx++; // next byte! } else cnt--; } // WRITE TO RIGHT VARS // as bits[1] and bits[3] are allways zero they are omitted in formulas. humidity = bits[0]; temperature = bits[2]; uint8_t sum = bits[0] + bits[2]; if (bits[4] != sum) return DHTLIB_ERROR_CHECKSUM; return DHTLIB_OK; } // // END OF FILE // // // FILE: dht11.h // VERSION: 0.4.1 // PURPOSE: DHT11 Temperature & Humidity Sensor library for Arduino // LICENSE: GPL v3 (http://www.gnu.org/licenses/gpl.html) // // DATASHEET: http://www.micro4you.com/files/sensor/DHT11.pdf // // URL: http://playground.arduino.cc/Main/DHT11Lib // // HISTORY: // George Hadjikyriacou - Original version // see dht.cpp file // #ifndef dht11_h #define dht11_h #if defined(ARDUINO) && (ARDUINO >= 100)
#include
#else
#include
#endif

#define DHT11LIB_VERSION "0.4.1"

#define DHTLIB_OK 0
#define DHTLIB_ERROR_CHECKSUM -1
#define DHTLIB_ERROR_TIMEOUT -2

class dht11
{
public:
int read(int pin);
int humidity;
int temperature;
};
#endif
//
// END OF FILE
//