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

#define codeLength 5  // Password length (including null terminator)
Servo myservo;  // Servo object
char Code[codeLength];  // Array to store entered password
char PassW[codeLength] = "1234";  // Correct password
byte keycount = 0;  // Track the number of keys pressed

// Keypad setup (4x4 matrix)
const uint8_t ROWS = 4;
const uint8_t COLS = 4;
char keys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};

// LCD setup (connected to pins 13, 11, 9, 8, 7, 6)
LiquidCrystal lcd(13, 11, 9, 8, 7, 6);
uint8_t rowPins[ROWS] = {26, 22, 21, 20}; 
uint8_t colPins[COLS] = {19, 18, 17, 16}; 

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

void setup() {
  lcd.begin(16, 2);  // Initialize the LCD with 16 columns and 2 rows
  lcd.print("Enter a Key:-");  // Display initial message on the LCD
  myservo.attach(28);  // Attach the servo to pin 28
}

void loop() {
  int pos;
  char customKey = customKeypad.getKey();  // Read the pressed key from the keypad
  
  if(customKey) {  // If a key is pressed
    Code[keycount] = customKey;  // Store the pressed key
    Serial.print(Code[keycount]);  // Print the key to the Serial Monitor
    lcd.setCursor(5, 1);  // Move the cursor to the second row
    lcd.print(Code[keycount]);  // Display the entered key
    keycount++;  // Increment the key count
  }
  
  // When the full password is entered (4 keys)
  if(keycount == codeLength - 1) {
    Serial.println("");  // Add a newline in the Serial Monitor for clarity
    
    // Check if the entered password matches the correct password
    if(strcmp(Code, PassW) == 0) {  // If passwords match
      Serial.println("Correct Password");
      lcd.clear();  // Clear the LCD screen
      lcd.setCursor(0, 0);  // Move the cursor to the first row
      lcd.print("Correct Password");  // Display "Correct Password"
      
      // Open the servo (rotate from 90 to 180 degrees)
      for(pos = 90; pos <= 180; pos++) {
        myservo.write(pos);  // Move the servo to the new position
        delay(40);  // Wait for the servo to reach the position
      }
      
      delay(1000);  // Wait for 1 second

      // Close the servo (rotate back from 180 to 90 degrees)
      for(pos = 180; pos >= 90; pos--) {
        myservo.write(pos);  // Move the servo back to 90 degrees
        delay(40);  // Wait for the servo to reach the position
      }
    } else {  // If the passwords do not match
      Serial.println("Incorrect Password");
      lcd.clear();  // Clear the LCD screen
      lcd.setCursor(0, 0);  // Move the cursor to the first row
      lcd.print("Wrong Password");  // Display "Wrong Password" on the LCD
      delay(2000);  // Wait for 2 seconds to display the message
    }
    
    deletecount();  // Reset the password input after checking
  }
}

// Function to reset the password input
void deletecount() {
  while(keycount != 0) {
    Code[keycount--] = 0;  // Clear the entered password
  }
  return;
}