#include <Keypad.h>

const byte ROWS = 4; // Four rows
const byte COLS = 4; // Four columns

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

// Define the keypad connection pins
byte rowPins[ROWS] = {19, 18, 5, 17}; // Connect to the row pinouts of the keypad
byte colPins[COLS] = {16, 4, 0, 2}; // Connect to the column pinouts of the keypad

// Create the Keypad object
Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );

// Define the pin connected to the LED
const int ledPin = 15;

void setup() {
  Serial.begin(9600); // Initialize serial communication
  pinMode(ledPin, OUTPUT);
  digitalWrite(ledPin, LOW); // Ensure LED is initially turned off
}

void loop() {
  // Get the key from the keypad
  char key = keypad.getKey();
  
  // Check if a key is pressed
  if (key != NO_KEY) {
    // Print the pressed key
    Serial.print("Key pressed: ");
    Serial.println(key);
    
    // Check which key is pressed
    if (key == '1') {
      digitalWrite(ledPin, HIGH); // Turn on the LED
      Serial.println("LED turned ON");
    } else if (key == '0') {
      digitalWrite(ledPin, LOW); // Turn off the LED
      Serial.println("LED turned OFF");
    }
  }
}