#include <Keypad.h>

const int RELAY_PIN = 10; // Relay pin
const int ROW = 4;       // Number of rows
const int COLUMN = 4;    // Number of columns

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

byte pin_rows[ROW] = {9, 8, 7, 6};     // Row pins
byte pin_column[COLUMN] = {5, 4, 3, 2}; // Column pins

Keypad keypad = Keypad(makeKeymap(keys), pin_rows, pin_column, ROW, COLUMN);

const String Pass = "1234"; // Set the password
String input_password;

void setup() {
  Serial.begin(9600);
  pinMode(RELAY_PIN, OUTPUT);        // Set relay pin as output
  digitalWrite(RELAY_PIN, LOW);      // Set relay to NC (Normally Closed)
  Serial.println("Masukkan Pin :");  // Initial prompt
}

void loop() {
  char key = keypad.getKey();

  if (key) {
    Serial.println(key);

    if (key == '*') { // Reset password input if '*' is pressed
      input_password = "";
      Serial.println("Input direset");
    } 
    else if (key == '#') { // Check password when '#' is pressed
      if (input_password == Pass) {
        Serial.println("PIN BENAR");
        digitalWrite(RELAY_PIN, HIGH); // Activate relay
        delay(5000);                   // Set duration
        digitalWrite(RELAY_PIN, LOW);  // Deactivate relay
      } 
      else {
        Serial.println("PIN SALAH");
        delay(3000); // Delay after incorrect password
      }
      input_password = ""; // Reset input for new attempts
      Serial.println("Masukkan Pin :"); // Prompt again
    } 
    else {
      input_password += key; // Add key to input
    }
  }
}