#include <LiquidCrystal.h>
#include <Keypad.h>

/* Display */
LiquidCrystal lcd(12, 11, 10, 9, 8, 7);

/* Keypad setup */
const byte KEYPAD_ROWS = 4;
const byte KEYPAD_COLS = 4;
byte rowPins[KEYPAD_ROWS] = {5, 4, 3, 2};
byte colPins[KEYPAD_COLS] = {A3, A2, A1, A0};
const int npm=2332061;
char keys[KEYPAD_ROWS][KEYPAD_COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, KEYPAD_ROWS, KEYPAD_COLS);

String sel_npm="2332061";
int is_right = 0;

// Cara Membaca Input Dari Keypad Adalah 
// keypad.getKey()

void setup() {
  lcd.begin(16, 2);
  lcd.print("Masukan NPM ");
}

void loop() {
  char npm = keypad.getKey();
  if (npm != NO_KEY) {
    if (npm == '#') {
      if (input == sel_npm) {
        lcd.clear();
        lcd.print("NPM Benar");
      } else {
        lcd.clear();
        lcd.print("NPM Salah");
      }
    } else {
      input += npm;
      lcd.setCursor(0, 1);
      lcd.print(input);
    }
    }}