#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 20, 4);

void setup() {
  lcd.backlight();
  lcd.begin(20, 4);
  initLCD();
  for(int i=2;i<6;i++) {
  	pinMode(i, INPUT_PULLUP);
  }
  pinMode(12, OUTPUT);
  pinMode(13, OUTPUT);
}

void initLCD() {
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Type passcode: ");
}

int currentNum=0;
int currentPass=0;
const int pass=2345;

void loop() {
  for(int i=2;i<6;i++) {
  	if(digitalRead(i) == LOW) {
      currentPass=currentPass*10;
      currentPass+=i;
      
      currentNum++;
      
      lcd.print(i);
      
      if(currentNum>3) {
        if(currentPass==pass) {
        	digitalWrite(12, HIGH);
        } else {
        	digitalWrite(13, HIGH);
        }
        currentNum=0;
        currentPass=0;
        initLCD();
      }
      delay(250);
      digitalWrite(13, LOW);
  	  digitalWrite(12, LOW);
    }
  }
  delay(10);
}