/*
 Voltaat learn (http://learn.voltaat.com)
 Link for full tutorial:
 LiquidCrystal I2C Library:
 Wire Library:
 Keypad Library:
 Servo Library:

 Tutorial: Build a Secure Safe with Password Protection

 Connections from the keypad to Arduino:
 • Keypad pin 1 → Arduino pin 2
 • Keypad pin 2 → Arduino pin 3
 • Keypad pin 3 → Arduino pin 4
 • Keypad pin 4 → Arduino pin 5
 • Keypad pin 5 → Arduino pin 6
 • Keypad pin 6 → Arduino pin 7
 • Keypad pin 7 → Arduino pin 8
 • Keypad pin 8 → Arduino pin 9

 Connections from the servo motor:
 • Servo GND pin→ breadboard GND line
 • Servo 5V pin→ breadboard 5V line
 • Servo signal pin → Arduino pin 10

 Connections from the LCD:
 • I2C module GND pin → Breadboard GND line
 • I2C module 5V pin → breadboard GND line
 • I2C module SDA pin → Arduino pin A4
 • I2C module SCL pin → Arduino pin A5

*/

// Define libraries
#include "Keypad.h"
#include "Wire.h"
#include "LiquidCrystal_I2C.h"
#include "Servo.h"

// Define the 4x4 keypad pins
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] = {9, 8, 7, 6}; // Connect to the row pinouts of the keypad
byte colPins[COLS] = {5, 4, 3, 2}; // Connect to the column pinouts of the keypad

// Initialize the keypad, LCD, and servo
Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );
LiquidCrystal_I2C lcd(0x27, 16, 2); // Set the LCD I2C address and dimensions
Servo myServo; // Create a Servo object

// Set password and other variables
String password = "1234B"; // Set the password to open the safe
const int MAX_PASSWORD_LENGTH = 4; // maximum password length, change accordingly
String enteredPassword = ""; // Store the entered password
bool safeOpen = false; // Store the state of the safe (open or closed)

// Commands inside void setup run once
void setup() {
 Serial.begin(9600); // Initialize serial communication
 lcd.init(); // Initialize the LCD
 lcd.backlight(); // Turn on the LCD backlight
 myServo.attach(10); // Attach the servo to pin 10
 myServo.write(0); // Initialize the servo to closed position
 lcd.setCursor(1, 0);
 lcd.print("Voltaat Learn"); // Display "Security Safe" on the first line
 lcd.setCursor(1, 1);
 lcd.print("Security Safe"); // Clear the second line
}

// Commands inside void loop run forever
void loop() {
 static bool showEnterPassword = false;
 static unsigned long prevMillis = 0;
 const unsigned long delayTime = 5000; // 5 seconds
 static bool showSafeClosed = false;
 static unsigned long safeClosedMillis = 0;
 const unsigned long safeClosedDelayTime = 2000; // 2 seconds

 // Show "Enter Password" message after 5 seconds
 if (!showEnterPassword && millis() - prevMillis >= delayTime) {
   showEnterPassword = true;
   prevMillis = millis();
   lcd.clear();
   lcd.setCursor(0, 0);
   lcd.print("Enter Password:");
 }

 // Read keypad input and handle password entry
 char key = keypad.getKey();
 if (showEnterPassword && key != NO_KEY) {
   if (key == '#') { // Check if enter key is pressed
     if (enteredPassword == password) { // Compare entered password with the correct password
       if (safeOpen) { // If safe is already open, close it and ask to enter password again
         safeOpen = false;
         lcd.clear();
         lcd.setCursor(0, 0);
         lcd.print("Press C to close");
         enteredPassword = ""; // Clear entered password
       } else { // If safe is closed, open it and ask to close it
         safeOpen = true;
         lcd.clear();
         lcd.setCursor(0, 0);
         lcd.print("Safe is open");
         lcd.setCursor(0, 1);
         lcd.print("Press C to close");
         myServo.write(90); // Open the safe by turning the servo to 90 degrees
         enteredPassword = ""; // Clear entered password

       }
     } else { // Incorrect password entered
       lcd.clear();
       lcd.setCursor(0, 0);
       lcd.print("Wrong Password!");
       delay(2000);
       lcd.clear();
       lcd.setCursor(0, 0);
       lcd.print("Enter Password:");
       enteredPassword = ""; // Clear entered password
     }
   } else if (key == '*') { // Check if clear key is pressed
     enteredPassword = ""; // Clear entered password
     lcd.clear();
     lcd.setCursor(0, 0);
     lcd.print("Enter Password:");
   } else if (key == 'C' || key == 'c') { // Check if C key is pressed
     if (safeOpen) { // If safe is open, close it
       safeOpen = false;
       lcd.clear();
       lcd.setCursor(0, 0);
       lcd.print("Safe is closed");
       myServo.write(0); // Close the safe by turning the servo to 0 degrees
       showSafeClosed = true;
       safeClosedMillis = millis();
       enteredPassword = ""; // Clear entered password
     }
   } else if (key == 'D' || key == 'd') { // Check if D key is pressed
     if (enteredPassword.length() > 0) { // If password is not empty, delete last character
       enteredPassword = enteredPassword.substring(0, enteredPassword.length() - 1);
       lcd.setCursor(0, 1);
       lcd.print("            "); // Clear the password field on the LCD screen
       lcd.setCursor(0, 1);
       // Print asterisks instead of the actual password characters
       for (int i = 0; i < enteredPassword.length(); i++) {
         lcd.print("*");
       }
     }
   } else { // Append entered key to the entered password
     if (enteredPassword.length() < 5 && !safeOpen) { // Limit password to 5 characters
       enteredPassword += key;
       lcd.setCursor(0, 1);
       // Print asterisks instead of the actual password characters
       for (int i = 0; i < enteredPassword.length(); i++) {
         lcd.print("*");
       }
     }
   }
 }

 // show "Safe Closed" message for 2 seconds after the safe is closed
 if (showSafeClosed && millis() - safeClosedMillis >= safeClosedDelayTime) {
   showSafeClosed = false;
   lcd.clear();
   lcd.setCursor(0, 0);
   lcd.print("Enter Password:");
 }
}