#include <DHT.h>
DHT dht22(4, DHT22); //Pin, SensorType

void setup (void)

{
    Serial.begin(9600);
    dht22.begin();
}

void loop (void)
{
  pinMode (8, OUTPUT);
  pinMode (9, OUTPUT);
  float temp = dht22.readTemperature();
  float hum = dht22.readHumidity();


 if (isnan(temp) || isnan(hum))
 {Serial.println("Failed to Read Sensor Data"); return;}

Serial.print("Temperature: ");
Serial.print(temp);
Serial.print("°C");
Serial.print("\t");

Serial.print("Humidity: ");
Serial.print(hum);
Serial.print("%");
Serial.println("");

delay(500);

   if(temp>=20){
    digitalWrite(8,LOW);
    digitalWrite(9,HIGH);
    delay(500);
  }
  else{
    digitalWrite(9,LOW);
    digitalWrite(8,HIGH);
    delay(500);
    }

}