#include <Keypad.h>
const uint8_t BARIS = 4;
const uint8_t KOLOM = 4;
char keys[BARIS][KOLOM] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};
uint8_t colPins[KOLOM] = {5, 4, 2, 15};
uint8_t rowPins[BARIS] = {22, 21, 19, 18};
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, BARIS, KOLOM);

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
}

void loop() {
  char key = keypad.getKey();
  if (key != NO_KEY) {
    Serial.println(key);
  }
}