#include <LiquidCrystal_I2C.h>
#include <DS18B20.h>

#define I2C_ADDR    0x27
#define LCD_COLUMNS 20
#define LCD_LINES   2

LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);
DS18B20 ds(2);

float fTemp;

void setup() {
  // Init
  lcd.init();
  lcd.backlight();

  // Print something
  lcd.setCursor(3, 0);
  lcd.print("Thermometer");
}

void loop() {
  lcd.setCursor(1, 1);
  fTemp = ds.getTempC();
  lcd.print(fTemp);
}