arduino.c

#include <Servo.h>
#include <Keypad.h>

Servo servoMotor;
const int servoPin = 913;  // Digital pin connected to the servo

const byte ROWS = 4; //four rows
const byte COLS = 4; //four columns
char keys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};
byte rowPins[ROWS] = {5, 4, 3, 2}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {9, 8, 7, 6}; //connect to the column pinouts of the keypad

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

const char* correctPIN = "6969"; // Change this to your correct PIN

void setup(){
  servoMotor.attach(servoPin);
  servoMotor.write(0); // Initialize servo at 0 degrees (closed position)
  Serial.begin(9600);
}

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

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

    static char enteredPIN[5]; // Stores entered digits
    static byte index = 0;   // Index to keep track of digit position

    if (key == '#'){
      // Check the entered PIN
      enteredPIN[index] = '\0'; // Null-terminate the string
      if (strcmp(enteredPIN, correctPIN) == 0){
        // Correct PIN entered, do something here (e.g., unlock the servo)
        servoMotor.write(90); // Rotate servo to 90 degrees (open position)
        delay(2000); // Wait for 2 seconds
        servoMotor.write(0); // Rotate servo back to 0 degrees (closed position)
        index = 0; // Reset index
      } else {
        // Incorrect PIN entered, do something here (e.g., indicate error)
        // In this example, we rotate the servo slightly as an error indication
        servoMotor.write(45); // Rotate servo to 45 degrees (partial open position)
        delay(500); // Wait for 0.5 seconds
        servoMotor.write(0); // Rotate servo back to 0 degrees (closed position)
        index = 0; // Reset index
      }
    } else {
      if (index < 4){
        enteredPIN[index] = key;
        index++;
      }
    }
  }
}