#include <Keypad.h>

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

byte colPins[COLS] = {32, 33, 25, 14}; // pin 2,3,4,5 untuk pin kolom keypad (lihat gambar)
byte rowPins[ROWS] = {5, 17, 16, 4}; // pin 6,7,8,9 untuk pin baris keypad (lihat gambar)

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

void setup(){
  Serial.begin(9600);
}

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