حســاس الرطــوبــة DHT22

// Example testing sketch for various DHT humidity/temperature sensors

#include "DHT.h"

#define DHTPIN 2 // what digital pin we're connected to

// Uncomment whatever type you're using!

//#define DHTTYPE DHT11 // DHT 11

#define DHTTYPE DHT22 // DHT 22 (AM2302), AM2321

//#define DHTTYPE DHT21 // DHT 21 (AM2301)

// Connect pin 1 (on the left) of the sensor to +5V

// NOTE: If using a board with 3.3V logic like an Arduino Due connect pin 1

// to 3.3V instead of 5V!

// Connect pin 2 of the sensor to whatever your DHTPIN is

// Connect pin 4 (on the right) of the sensor to GROUND

// Connect a 10K resistor from pin 2 (data) to pin 1 (power) of the sensor

// Initialize DHT sensor.

// Note that older versions of this library took an optional third parameter to

// tweak the timings for faster processors. This parameter is no longer needed

// as the current DHT reading algorithm adjusts itself to work on faster procs.

DHT dht(DHTPIN, DHTTYPE);

void setup() {

   Serial.begin(9600);

   Serial.println("DHTxx test!");

   dht.begin();

}

void loop() {

   delay(2000); // Wait a few seconds between measurements

   float h = dht.readHumidity();

   // Reading temperature or humidity takes about 250 milliseconds!

   float t = dht.readTemperature();

   // Read temperature as Celsius (the default)

   float f = dht.readTemperature(true);

   // Read temperature as Fahrenheit (isFahrenheit = true)

   // Check if any reads failed and exit early (to try again).

   if (isnan(h) || isnan(t) || isnan(f)) {

      Serial.println("Failed to read from DHT sensor!");

      return;

   }

   // Compute heat index in Fahrenheit (the default)

   float hif = dht.computeHeatIndex(f, h);

   // Compute heat index in Celsius (isFahreheit = false)

   float hic = dht.computeHeatIndex(t, h, false);

   Serial.print ("Humidity: ");

   Serial.print (h);

   Serial.print (" %\t");

   Serial.print ("Temperature: ");

   Serial.print (t);

   Serial.print (" *C ");

   Serial.print (f);

   Serial.print (" *F\t");

   Serial.print ("Heat index: ");

   Serial.print (hic);

   Serial.print (" *C ");

   Serial.print (hif);

   Serial.println (" *F");

}