#include "DHT.h" 
#define DHTPIN 3  
#define DHTTYPE DHT22 
DHT dht(DHTPIN, DHTTYPE); 
void setup() {
  Serial.begin(9600); 
  Serial.println(F("DHT22 test!")); 
  dht.begin(); 
}
void loop() {
  float t = dht.readTemperature(); 
  float h = dht.readHumidity();
  if (isnan(t) || isnan(h)) 
  {
    Serial.println(F("Failed to read from DHT sensor!"));
    return; 
  }
  Serial.print(F("Humidity: ")); 
  Serial.print(h);
  Serial.print(F("%  Temperature: ")); 
  Serial.print(t);
  Serial.println(F("°C "));
  delay(1000);
}