#include <Keypad.h>

const byte ROWS = 4; 
const byte COLS = 4; 

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

byte rowPins[ROWS] = {2, 3, 4, 5};  
byte colPins[COLS] = {6, 7, 8, 9};  

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

const int ledPin = 13;  

void setup() {
    pinMode(ledPin, OUTPUT);
    Serial.begin(9600);
}

void loop() {
    char key = keypad.getKey();
    if (key) {  // 키가 눌렸을 때
        Serial.print("Pressed Key: ");
        Serial.println(key);

        digitalWrite(ledPin, HIGH);
        delay(300);
        digitalWrite(ledPin, LOW);
    }
}