//YWROBOT
//Compatible with the Arduino IDE 1.0
//Library version:1.1
#include <LiquidCrystal_I2C.h>
#include <Keypad.h>

// set the LCD address to 0x27 for a 20 chars and 4 line display
LiquidCrystal_I2C lcd(0x27,20,4);  
//set Pin Baris & Kolom Keypad
const byte ROWS = 4; //4 Baris
const byte COLS = 4; //4 Kolom
char keys[ROWS][COLS] = {
  {'1','2','3','A'}, //Mapping keypad Baris Pertama
  {'4','5','6','B'}, //Mapping keypad Baris ke dua
  {'7','8','9','C'}, //Mapping keypad Baris ke tiga
  {'*','0','#','D'}  //Mapping keypad Baris ke empat
};
byte rowPins[ROWS] = {5, 4, 3, 2};     //sambungan Pin baris (Row) Keypad
byte colPins[COLS] = {A0, A1, A2, A3}; //sambungan Pin kolom (column) Keypad

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

void setup()
{
  lcd.init();                      // initialize the lcd 
  // Print a message to the LCD.
  lcd.backlight();                 //Nyalakan Lampu Backlight
  lcd.setCursor(0,0);              //Set Kursor Kolom: 0 Baris: 0 
  lcd.print("Teknik Elektro S1");  //Menampilkan Tulisan: Teknik Elektro S1
  delay(1000);                     //jeda 1 detik (1000 ms)
  lcd.setCursor(0,1);              //Set Kursor Kolom: 0 Baris: 1 
  lcd.print("Kelas Karyawan");     //Menampilkan Tulisan: Kelas Karyawan
  delay(1000);                     //jeda 1 detik (1000 ms)
   lcd.setCursor(0,2);             //Set Kursor Kolom: 0 Baris: 2
  lcd.print("P.Mikroprosessor 3"); //Menampilkan Tulisan: P.Mikroprosessor 3
  delay(1000);                     //jeda 1 detik (1000 ms)
   lcd.setCursor(0,3);             //Set Kursor Kolom: 0 Baris: 3
  lcd.print("Keypad & LCD");       //Menampilkan Tulisan: Keypad & LCD
  delay(1000);                     //jeda 1 detik (1000 ms)
  lcd.clear();                     //hapus semua karakter di LCD
}

void loop()
{
  char key = keypad.getKey();//jika ada tombol keypad yang ditekan, 
                             //masukkan hasil pada variabel key
  if (key){                  //jika variabel key terdapat nilai
    lcd.setCursor(0,0);      //Set Kursor Kolom: 0 Baris: 0
    lcd.print(key);          //tampilkan hasil pembacaan Keypad pada LCD
  }
}