#include <LiquidCrystal_I2C.h>

#define I2C_ADDR 0x27
#define LCD_COLUMNS 20
#define LCD_LINES 4

LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

int num = 100;

void setup() {
  // put your setup code here, to run once:
  lcd.init();
  lcd.backlight();

  lcd.print("Hello World");


}

void loop() {
  // put your main code here, to run repeatedly:
delay(1000);
lcd.clear();
lcd.print(readTemp());

}

float readTemp(){
  const float BETA = 3950;
  int analogValue = analogRead(A0);
  float celsius = 1 / (log(1 / (1023. / analogValue - 1)) / BETA + 1.0 / 298.15) - 273.15;
  return celsius;
}