// LCD1602 and Pi Pico!

#include <LiquidCrystal.h>
#include <Keypad.h>
#define Password_Lenght 7

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' }
};

uint8_t colPins[COLS] = { 16, 17, 18, 19 }; // Pins connected to C1, C2, C3, C4
uint8_t rowPins[ROWS] = { 20, 21, 22, 5 }; // Pins connected to R1, R2, R3, R4

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

LiquidCrystal lcd(12, 11, 10, 9, 8, 7);

char Data[Password_Lenght]; 
char Master[Password_Lenght] = "A1B2C3"; 
byte data_count = 0, master_count = 0;
bool Pass_is_good;

void setup() {

  lcd.begin(16, 2);
  lcd.print("Input Password:");
  lcd.setCursor(0, 1);
  lcd.print("******");
}

void loop() {
  delay(1); 
  char key = keypad.getKey();

  if (key) // makes sure a key is actually pressed, equal to (customKey != NO_KEY)
  {
    Data[data_count] = key; // store char into data array
    lcd.setCursor(data_count,1); // move cursor to show each new char
    lcd.print(Data[data_count]); // print char at said cursor
    data_count++; // increment data array by 1 to store new char, also keep track of the number of chars entered
  }

  if(data_count == Password_Lenght-1) // if the array index is equal to the number of expected chars, compare data to master
  {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Pwd ");

    if(!strcmp(Data, Master)) // equal to (strcmp(Data, Master) == 0)
      lcd.print("Accepted");
    else
      lcd.print("Denied");

    delay(1000);// added 1 second delay to make sure the password is completely shown on screen before it gets cleared.   
    lcd.clear();
    clearData();
  }
}

void clearData()
{
  while(data_count !=0)
  {   // This can be used for any array size, 
    Data[data_count--] = 0; //clear array for new data
  }
  return;
}