#include <Keypad.h>

// Define the number of rows and columns in the keypad
const byte ROWS = 4;
const byte COLS = 4;

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

// Define the pin numbers for the keypad
byte rowPins[ROWS] = {9, 8, 7, 6};  
byte colPins[COLS] = {5, 4, 3, 2};  

// Define the pin numbers for the LEDs
const int ledPins[] = {10, 11, 12, 13};  

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

void setup() {
  for (int i = 0; i < sizeof(ledPins) / sizeof(ledPins[0]); i++) {
    pinMode(ledPins[i], OUTPUT);
  }
  Serial.begin(9600);
}

void loop() {
  char key = keypad.getKey();
  if (key) {
    Serial.println("Key Pressed: " + String(key));
    handleLED(key);
  }
  
}

void handleLED(char key) {
  // Turn off all LEDs initially
  for (int i = 0; i < sizeof(ledPins) / sizeof(ledPins[0]); i++) {
    digitalWrite(ledPins[i], LOW);
  }

  // Determine which LED to turn on based on the pressed key
  switch (key) {
    case 'A':
      digitalWrite(ledPins[0], HIGH);  // Turn on LED corresponding to 'A'
      break;
    case 'B':
      digitalWrite(ledPins[1], HIGH);  // Turn on LED corresponding to 'B'
      break;
    case 'C':
      digitalWrite(ledPins[2], HIGH);  // Turn on LED corresponding to 'C'
      break;
    case 'D':
      digitalWrite(ledPins[3], HIGH);  // Turn on LED corresponding to 'D'
      break;
    default:
      break;
  }
}