//RANGGA AULIA RAHMAN
//20/456849/TK/50673

/*********************************************/

const byte ROWS = 4; //four rows
const byte COLS = 4; //three columns
char keys[ROWS][COLS] = {//mapping karakter
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};
byte rowPins[ROWS] = {4, 5, 6, 7}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {8, 9, 10, 11}; //connect to the column pinouts of the keypad
//Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );
//LiquidCrystal_I2C lcd(0x27,16,2);  // set the LCD address to 0x27 for a 16 chars and 2 line display

unsigned char debouncing (int i)
{
      delay(10);
      if(digitalRead(colPins[i])==LOW)
      {
        delay(10);
        while (!(digitalRead(colPins[i]))){};
        return i;
      }
    
}

unsigned char cek_kolom(void)
{
  for (int i = 0; i < 4; i++)
  {
    if (digitalRead(colPins[i])==LOW)
    
    {
    return debouncing(i);
    }
  }
  return (4);
}
  
unsigned char _activate_row(unsigned char row_th)
{

  unsigned char out_clm;
  
  //DDRF|=0x0F;
  //PORTF=0xFF;
  for(char i=0;i<4;i++){
    digitalWrite(rowPins[i], HIGH);
  }
  digitalWrite(rowPins[row_th],LOW);
  out_clm=cek_kolom();
  return out_clm;
}
unsigned char ReadKeypad(void)
{
  unsigned char tmp, get_dt_loop,conter_tmb;
  
  tmp=4;
  for (conter_tmb=0;conter_tmb<4;conter_tmb++)
  {
    tmp=_activate_row(conter_tmb);
    if(tmp<4)
      return keys[conter_tmb][tmp];     
  }
  if(conter_tmb==4) return 0;
}
void setup() {
  // put your setup code here, to run once:
    char i;
    for(i=0;i<4;i++){
      pinMode(rowPins[i], OUTPUT);
      pinMode(colPins[i], INPUT_PULLUP);
    }
    Serial.begin(115200);
}

void loop() {
  // put your main code here, to run repeatedly:
    unsigned char keypressed = ReadKeypad();
    if (keypressed != 0)
    {
      Serial.println((char)keypressed);
    }
}