/*
  Project:  4x4 rigid keypad, LEDs, active piezo buzzer, LCD1602 I2C module / security code
  Function: This sketch takes input from a keypad for secret code.  If the code is
           entered correctly it turns on a green LED to simulate access granted and
           prints access granted in Serial Monitor and on LCD screen. Otherwise the red LED is lit and
           access denied is printed in Serial Monitor and on LCD screen.
*/
//**********************************************************************************
#include <Keypad.h>//include library code
#include <EEPROM.h>//include library code
#include "pitches.h"//include library code
#include <LiquidCrystal_I2C.h>//include library code
//******************************************************************************************
// Melodies definition: access and rejection - you can change melodies. see in file pitches.h
int keypadRead;  // keypad read 1 = good, 0 = bad for playTune function
int access_melody[] = { NOTE_C4, NOTE_G3, NOTE_G3, NOTE_A3, NOTE_G3, 0, NOTE_B3, NOTE_C4};
int access_noteDurations[] = {4, 8, 8, 4, 4, 4, 4, 4};
int noaccess_melody[] = {NOTE_G2, NOTE_G2};
int noaccess_noteDurations[] = {8, 8};
const int buzzerPin = 12;           //active piezo buzzer attached to digital pin 12

LiquidCrystal_I2C lcd(0x3F, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);//Initialise the LCD 1602 I2C module

const int greenledPin = 10; //green LED attached to digital pin 10
const int redledPin = 11;   //red LED attached to digital pin 11
char password[8];
char pass[8], pass1[8];
int i = 0;
char customKey = 0;
const byte rows = 4;      //number of keypad rows
const byte cols = 4;      //number of keypad columns
char keys[rows][cols] = { //enter the setup of your keypad
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};
byte rowPins[rows] = {5, 4, 3, 2}; //ROW1, ROW2, ROW3 and ROW4 pins declared here. Change them to yours
byte colPins[cols] = {6, 7, 8, 9}; //COL1, COL2, COL3 and COL4 pins declared here. Change them to yours
Keypad customKeypad = Keypad(makeKeymap(keys), rowPins, colPins, rows, cols);
//************************************************************************************************
void setup()
{
  pinMode(buzzerPin, OUTPUT);           //sets buzzerPin as OUTPUT
  pinMode(greenledPin, OUTPUT);         //sets greenledPin as OUTPUT
  pinMode(redledPin, OUTPUT);           //sets redledPin as OUTPUT
  Serial.begin(9600);                   //initialise the serial communication at 9600 bps

  lcd.begin (16, 2);//Define the LCD as 16 column by 2 rows
  lcd.setBacklightPin(3, POSITIVE);//Switch on the backlight
  lcd.setBacklight(HIGH);
  lcd.print("***Electronic***");//Print at cursor Location
  lcd.setCursor(0, 1); //goto first column (column 0) and second line (line 1)
  lcd.print("***Keypad Lock**");//Print at cursor Location

  Serial.println("********************");
  Serial.println("*****Electronic*****");
  Serial.println("*****Keypad Lock****");
  Serial.println("********************");
  delay(2000);

  lcd.clear();
  lcd.print("Enter code:");
  lcd.setCursor(0, 1); //goto first column (column 0) and second line (line 1)
  lcd.blink();
  Serial.println("*****Enter code*****");

  for (int j = 0; j < 8; j++) //password set to 8 symbols: default is 12345678
    EEPROM.write(j, j + 49);  //if you want to have a different password lengh - change number 8 everywere in void loop() to your number
  for (int j = 0; j < 8; j++)
    pass[j] = EEPROM.read(j);
}

void loop()
{
  customKey = customKeypad.getKey();
  if (customKey == '#')
    change();
  if (customKey)
  {
    password[i++] = customKey;

    lcd.setCursor(i - 1, 1);
    lcd.print(customKey);

    Serial.print(customKey);
  }
  if (i == 8)
  {
    delay(200);
    for (int j = 0; j < 8; j++)
      pass[j] = EEPROM.read(j);
    if (!(strncmp(password, pass, 8)))
    {
      lcd.clear();
      lcd.print("***Electronic***");//Print at cursor Location
      lcd.setCursor(0, 1); //goto first column (column 0) and second line (line 1)
      lcd.print("*Access granted*");

      keypadRead = 1;
      playTune(keypadRead);
      digitalWrite(greenledPin, HIGH);
      Serial.println("");
      Serial.println("********************");
      Serial.println("** ACCESS GRANTED **");
      Serial.println("**   WELCOME!!    **");
      Serial.println("********************");
      delay(2000);

      lcd.clear();
      lcd.print("Use # to change code");//Print at cursor Location

      Serial.println("Use # to change code");
      delay(2000);

      lcd.clear();
      lcd.print("Enter code:");
      lcd.setCursor(0, 1); //goto first column (column 0) and second line (line 1)
      lcd.blink();

      Serial.println("********************");
      Serial.println("*****Enter code*****");
      i = 0;
      digitalWrite(greenledPin, LOW);
    }

    else
    {
      keypadRead = 0;
      playTune(keypadRead);
      digitalWrite(redledPin, HIGH);

      lcd.clear();
      lcd.print("***Electronic***");//Print at cursor Location
      lcd.setCursor(0, 1); //goto second column (column 2) and second line (line 1)
      lcd.print("**Access denied*");

      Serial.println("");
      Serial.println("********************");
      Serial.println("** ACCESS DENIED! **");
      Serial.println("**  INVALID CODE  **");
      Serial.println("********************");
     
      delay(2000);
      lcd.clear();
      lcd.print("Use # to change code");//Print at cursor Location

      Serial.println("Use # to change code");
      delay(2000);

      lcd.clear();
      lcd.print("Enter code:");
      lcd.setCursor(0, 1); //goto first column (column 0) and second line (line 1)
      lcd.blink();

      Serial.println("********************");
      Serial.println("*****Enter code*****");
      i = 0;
      digitalWrite(redledPin, LOW);
    }
  }
}
void change()
{
  int j = 0;

  lcd.clear();
  lcd.print("Enter old code:");
  lcd.setCursor(0, 1); //goto first column (column 0) and second line (line 1)
  lcd.blink();

  Serial.println("*Enter current code*");
  while (j < 8)
  {
    char key = customKeypad.getKey();
    if (key)
    {
      pass1[j++] = key;

      lcd.setCursor(j-1, 1);
      lcd.print(customKey);

      Serial.print(key);
    }
    key = 0;
  }
  delay(500);

  if ((strncmp(pass1, pass, 8)))
  {
    keypadRead = 0;
    playTune(keypadRead);

    digitalWrite(redledPin, HIGH);
    lcd.clear();
    lcd.print("***Electronic***");//Print at cursor Location
    lcd.setCursor(0, 1); //goto second column (column 2) and second line (line 1)
    lcd.print("**Access denied*");

    Serial.println("");
    Serial.println("********************");
    Serial.println("** ACCESS DENIED! **");
    Serial.println("**  INVALID CODE  **");
    Serial.println("********************");
    delay(1000);
  }
  else
  {
    j = 0;

    lcd.clear();
    lcd.print("Enter new code:");
    lcd.setCursor(0, 1); //goto first column (column 0) and second line (line 1)
    lcd.blink();

    Serial.println("");
    Serial.println("***Enter new code***");
    while (j < 8)
    {
      char key = customKeypad.getKey();
      if (key)
      {
        pass[j] = key;

        lcd.setCursor(j, 1);
        lcd.print(customKey);

        Serial.print(key);
        EEPROM.write(j, key);
        j++;
      }
    }

    lcd.clear();
    lcd.print("Code changed");//Print at cursor Location

    Serial.println("");
    Serial.println("**Your code changed*");
    Serial.println("********************");
    delay(2000);
  }
  lcd.clear();
  lcd.print("Enter code:");
  lcd.setCursor(0, 1); //goto first column (column 0) and second line (line 1)
  lcd.blink();
  Serial.println("*****Enter code*****");
  customKey = 0;
}
//**************************************************************
//Function to play the melody during Access and No access
void playTune(int Scan) {
  if (Scan == 1) // Correct secret code entered - Access granted
  {
    for (int i = 0; i < 8; i++)    //loop through the notes
    { // Good secret code read
      int access_noteDuration = 1000 / access_noteDurations[i];
      tone(buzzerPin, access_melody[i], access_noteDuration);
      int access_pauseBetweenNotes = access_noteDuration * 1.30;
      delay(access_pauseBetweenNotes);
      noTone(buzzerPin);
    }
  }
  else // Wrong secret code entered - No Access
    for (int i = 0; i < 2; i++)    //loop through the notes
    {
      int noaccess_noteDuration = 1000 / noaccess_noteDurations[i];
      tone(buzzerPin, noaccess_melody[i], noaccess_noteDuration);
      int noaccess_pauseBetweenNotes = noaccess_noteDuration * 1.30;
      delay(noaccess_pauseBetweenNotes);
      noTone(buzzerPin);
    }
}