//------------------------------------------------Include|
  #include <Keypad.h>
  #include <LiquidCrystal.h>
//------------------------------------------------setup|
  LiquidCrystal lcd(13, 12, 11, 10, 9, 8);
  void setup() {
    lcd.begin(16, 2); }
//------------------------------------------------pinPad|
  #define passLength 16
  char userInput[passLength];
  char Master[passLength] = "1234"; //change the numbers in the "" to change the password
  char customKey;
  byte pressCount = 0;
  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', 'D' },
    { 'E', '0', 'C', 'F' } 
  };
  uint8_t colPins[COLS] = { 18, 19, 20, 21 }; // Pins connected to C1, C2, C3, C4
  uint8_t rowPins[ROWS] = { 14, 15, 16, 17 }; // Pins connected to R1, R2, R3, R4
  Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);
//------------------------------------------------password, clear and check|
  void password(){  //checks what number is pressed
    customKey = keypad.waitForKey(); //waits until a button is pressed
    if(customKey != 'E' && customKey != 'C'){ //if anything except clear and enter button is pressed
    userInput[pressCount] = customKey; 
    lcd.setCursor(pressCount,1);
    lcd.print("*"); //if you input a number it prints a *
    pressCount++; } else {
      check(); //if a clear or enter button is pressed
    } }
  void clearData() { //code to clear 
  while (pressCount != 0) {
  userInput[pressCount] = 0; 
  pressCount--; }
  setup(); 
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Password:");
  lcd.setCursor(0,0); }
  void check(){ //code that checks if e or c is pressed
    if(customKey == 'E'){
      if (!strcmp(userInput, Master)){
        //what happens if you put in the correct password
        clearData();
      } else if (strcmp(userInput, Master)){
        //what happens if you put in the incorrect password
        clearData();
      } }
  if(customKey == 'C'){ //clear button
      clearData(); }  }
//------------------------------------------------loop|
  void loop() {
    password(); 
  }