#include "DHT.h"
#define DHTPIN 2// you can use 
#define DHTTYPE DHT22//#define DHTTYPE DHT21
                     //#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);//you can also use pins 3, 4, 5, 12, 13 or 14
   // Pin 15 can work but DHT must be disconnected during program upload
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);
void setup() {
 Serial.begin(9600);
 Serial.println("DHT22 test!");
 dht.begin();// initialize the sensor
 lcd.backlight();// turn on lcd backlight
 lcd.init();// initialize lcd
 lcd.setCursor(0, 0); 
 lcd.print("RPCA");
 lcd.setCursor(2, 1);
 lcd.print("DHT22 Test");
 delay(2000);
}
void loop() {
  float h = dht.readHumidity();
  float t = dht.readTemperature();
  if (isnan(h) || isnan(t)) {
Serial.println("Failed to read from DHT sensor!");
return;
  }
 lcd.clear();
   lcd.setCursor(0,0);
   lcd.print("Temp : ");
   lcd.setCursor(7, 0);
   lcd.print(t);
   lcd.print(" C");
   lcd.setCursor(0,1);
   lcd.print("Humi : ");
   lcd.setCursor(7,1);
   lcd.print(h);
   lcd.print(" %RH");
   delay(2000);
}