#include <LiquidCrystal_I2C.h>

#define temp A0
const float BETA = 3950;
#define I2C_ADDR    0x27
#define LCD_COLUMNS 20
#define LCD_LINES   4
LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

byte pos = 0;
boolean dir = true;

void setup ()
{
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(temp, OUTPUT);
  lcd.init();
  lcd.backlight();
  
}

void loop ()
{
  // put your main code here, to run repeatedly:
    float currTemp = analogRead(temp);
    float convertedTemp = 1 / (log(1 / (1023. / currTemp - 1)) / BETA + 1.0 / 298.15) - 273.15;
    
    if ( dir )
    {
      if ( pos < 15 )
      {
        pos ++;
        lcd.scrollDisplayRight ();
      }
      else dir = false;
    }
    else
    {
      if ( pos > 0 )
      {
        pos --;
        lcd.scrollDisplayLeft ();
      }
      else dir = true;
    
    }

    lcd.setCursor(0, 0);
    lcd.print(convertedTemp);
    delay(200);
}