Library:
1.HD44780 By Bill Perry
https://github.com/duinoWitchery/hd44780
2.Keypad By Mark Stanley
https://github.com/Chris--A/Keypad


#include <Wire.h>
#include <hd44780.h>
#include <hd44780ioClass/hd44780_I2Cexp.h>
#include <Keypad.h>

hd44780_I2Cexp lcd;


const byte ROWS = 4;
const byte COLS = 4;

char keys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};

byte rowPins[ROWS] = {19, 18, 5, 17};
byte colPins[COLS] = {16, 4, 2, 15};

Keypad keypad = Keypad(
  makeKeymap(keys),
  rowPins,
  colPins,
  ROWS,
  COLS
);


#define BUZZER_PIN 27

int posisi = 0;

void setup() {

  Serial.begin(115200);

  Wire.begin(21, 22);

  int status = lcd.begin(16, 2);

  if (status) {
    Serial.print("LCD ERROR: ");
    Serial.println(status);
    while (1);
  }

  pinMode(BUZZER_PIN, OUTPUT);

  lcd.clear();

  lcd.setCursor(0, 0);
  lcd.print("Tekan Tombol:");

  lcd.setCursor(0, 1);
}

void loop() {

  char key = keypad.getKey();

  if (key != NO_KEY) {


    tone(BUZZER_PIN, 1000);
    delay(50);
    noTone(BUZZER_PIN);


    if (key == '*') {

      if (posisi > 0) {

        posisi--;

        lcd.setCursor(posisi, 1);
        lcd.print(" ");

        lcd.setCursor(posisi, 1);
      }

      Serial.println("HAPUS");

      return;
    }


    if (posisi < 16) {

      lcd.setCursor(posisi, 1);
      lcd.print(key);

      posisi++;
    }

    Serial.print("Tombol = ");
    Serial.println(key);
  }
}