#include "DHT.h"
#define DHTPIN 3     
#define DHTTYPE DHT22   

byte i=0;
float temperature, humidity;

DHT dht(DHTPIN, DHTTYPE);

void setup() {
  Serial.begin(115200);
  pinMode(12,1);
  pinMode(13,1);
  pinMode(11,1);
  pinMode(10,1);
  dht.begin();
}

void loop() {
  temperature = dht.readTemperature();
  humidity = dht.readHumidity();

  if (isnan(temperature) || isnan(humidity)) {
    Serial.println(F("Failed to read from DHT sensor!"));
    return;
  }
  Serial.print(F("Humidity: "));
  Serial.print(humidity);
  Serial.print(F("%  Temperature: "));
  Serial.print(temperature);
  Serial.println(F("°C "));
if ((temperature>=20)&&(temperature<30)){
if(i==0)                 {
  digitalWrite(13,1);
  i=1;
 }
else      {

  digitalWrite(13,0);
  i=0;  
 }

 }
if ((temperature>=30)&&(temperature<40)){
if (i==0){
digitalWrite(13,1);
digitalWrite(12,1);
i=1; 
} else{
digitalWrite(13,1);
digitalWrite(12,0);
i=0;
}
}
if ((temperature>=40)&&(temperature<50)){
if (i==0){
digitalWrite(13,1);
digitalWrite(12,1);
digitalWrite(11,1);
i=1; 
} else{
digitalWrite(13,1);
digitalWrite(12,1);
digitalWrite(11,0);
i=0;
}
}
if (temperature>=50){
if (i==0){
digitalWrite(13,1);
digitalWrite(12,1);
digitalWrite(11,1);
digitalWrite(10,1);
i=1; 
} else{
digitalWrite(13,0);
digitalWrite(12,0);
digitalWrite(11,0);
digitalWrite(10,0);
i=0;
}
}
  // Wait a few seconds between measurements.
  delay(1000);
}