#include <Keypad.h>
#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);

const byte ROWS = 4; //four rows
const byte COLS = 3; //three columns
char keys[ROWS][COLS] = {
  {'1','2','3'},
  {'4','5','6'},
  {'7','8','9'},
  {'*','0','#'}
};
byte rowPins[ROWS] = {5, 4, 3, 2}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {8, 7, 6}; //connect to the column pinouts of the keypad

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

void setup(){
  Serial.begin(9600);
  lcd.init();
  lcd.backlight();

  // Print something
  lcd.setCursor(1, 0);
  lcd.print("Hello");
  lcd.setCursor(1, 1);
  lcd.print("Keypad Matriks");
  delay(2000);
  lcd.clear();
}
  
void loop(){
  lcd.setCursor(0, 0);
  lcd.print("Key pressed : ");
  char key = keypad.getKey();
  if (key){
    Serial.println(key);
    lcd.setCursor(14, 0);
    lcd.println(key);
    if (key == '1') {
      tone(9, 500);
      lcd.setCursor(6,1);
      lcd.print("Do");
    }
    else if (key == '2') {
      tone(9, 1000);
      lcd.setCursor(6,1);
      lcd.print("Re");
    }
    else
      noTone(9);
  }
}