temp_with_lcd.ino

// Example testing sketch for various DHT humidity/temperature sensors
// Written by ladyada, public domain
#include <LiquidCrystal.h>
#include "DHT.h"

#define DHTPIN 2     // what pin we're connected to

// Uncomment whatever type you're using!
//#define DHTTYPE DHT11   // DHT 11 
//#define DHTTYPE DHT22   // DHT 22  (AM2302)
#define DHTTYPE DHT21   // DHT 21 (AM2301)

// Connect pin 1 (on the left) of the sensor to +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

DHT dht(DHTPIN, DHTTYPE);
LiquidCrystal lcd(12, 11, 4, 5, 6, 7);

void setup() {
  lcd.begin(16, 2);
  dht.begin();
}

void loop() {
  // 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();
  float t = dht.readTemperature();
   lcd.clear();
   lcd.setCursor(0, 0);
   
  // check if returns are valid, if they are NaN (not a number) then something went wrong!
  if (isnan(t) || isnan(h)) {
    lcd.print("Failed to read from DHT");
  } else {
    lcd.print("Hum: "); 
    lcd.print(h);
    lcd.print(" %");
    lcd.setCursor(0, 1);
    lcd.print("Temp: "); 
    lcd.print(t);
    lcd.print(" *C");
  }
  
}