DHT22

// Example testing sketch for various DHT humidity/temperature sensors
// Written by ladyada, public domain
#include <Adafruit_Sensor.h>
#include "DHT.h"
#define DHTPIN 8     // 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() {
 // Wait a few seconds between measurements.
 delay(2000);
 // Reading temperature or humidity takes about 250 milliseconds!
 // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
 float h = dht.readHumidity();
 // Read temperature as Celsius (the default)
 float t = dht.readTemperature();
 // Read temperature as Fahrenheit (isFahrenheit = true)
 float f = dht.readTemperature(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");
}