#include <Keypad.h>

#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27,20,4); 

const char LED_RED = A0;
const char LED_GREEN = A1;
const char LED_BLUE = A2;

const char LED_OP = A3;

const char Buzzer = 125;

#define Password_Length 9 // Length of password + 1 for null character

char Data[Password_Length]; // Character to hold password input

char Master[Password_Length] = "17293364"; // Password

byte data_count = 0; // Counter for character entries

const byte numRows= 4; //number of rows on the keypad
const byte numCols= 3; //number of columns on the keypad

char keymap[numRows][numCols]= 
{
{'1', '2', '3'}, 
{'4', '5', '6'}, 
{'7', '8', '9'},
{'*', '0', '#'}
};

byte rowPins[numRows] = {8,7,6,5}; //Rows 0 to 3
byte colPins[numCols]= {4,3,2}; //Columns 0 to 3

Keypad myKeypad= Keypad(makeKeymap(keymap), rowPins, colPins, numRows, numCols);


void setup()
{
  lcd.init();   // initialize the lcd
  lcd.backlight();
  lcd.setCursor(6,0);
  lcd.print("WELCOME");
  
  delay(1000); 

  lcd.setCursor(0,2);
  lcd.print("Enter Password:");
  
  pinMode(LED_GREEN,OUTPUT);
  pinMode(LED_RED,OUTPUT);
  pinMode(LED_OP,OUTPUT);
  
  digitalWrite(Buzzer,HIGH);
  delay(2000);
  digitalWrite(Buzzer, LOW);
  digitalWrite(LED_RED,HIGH);
}

void loop()
{
  
  char keypressed = myKeypad.getKey();
  
if (keypressed != NO_KEY && keypressed != '*') // Data input for array 
{
  if (keypressed != NO_KEY && keypressed != '#')
  {
     
    Data[data_count] = keypressed;
    lcd.setCursor(data_count, 3);
    lcd.print(Data[data_count]);
    data_count++;
      
   }  
}
  
  if(keypressed == '*') // to delit last char entry (*-key)
  { 
     data_count = data_count-1;  
     lcd.setCursor(data_count, 3);
     lcd.print(' ');
    
   }  
  
 if(keypressed == '#') // to delit last char entry (*-key)
  { 
   
    clearData();
    lcd.setCursor(0,3);
    lcd.print("          ");
   }   
  
   
if (data_count == Password_Length - 1) // See if we have reached the password length
 {
     lcd.clear();
 
    if (!strcmp(Data, Master)){// Password is correct
     
      ATH_DONE();                      
  }
    else 
      
   {
      ATH_FAIL();
   }
    clearData();
  }
}  


void ATH_DONE() {
      
      digitalWrite(LED_RED,LOW);
      digitalWrite(LED_GREEN,LOW);
  
      lcd.setCursor(2,0);
      lcd.print("CORRECT PASSWORD");
      delay(1000);
      lcd.setCursor(2,2);
      lcd.print("SENSORS ACTIVATED");
      
      digitalWrite(LED_GREEN,HIGH);
      digitalWrite(LED_OP,HIGH);
} 


void ATH_FAIL() {
      
      digitalWrite(LED_RED,LOW);
      digitalWrite(LED_GREEN,LOW);
  
      lcd.setCursor(5,0);
      lcd.print("ATH FAILED");
      lcd.setCursor(0,2);
      lcd.print("Incorrect Password");

      delay(1000);
      
       clearData();
       lcd.clear(); 
       lcd.setCursor(6,0);
       lcd.print("WELCOME");
       lcd.setCursor(0,2); // Initialize LCD and print
       lcd.print("Re-Enter PSWRD:");
      
      digitalWrite(LED_RED,HIGH);
} 


void clearData() {
  
  while (data_count != 0) // Go through array and clear data
  {
    Data[data_count--] = 0;
  }
  return;
}