// STM32 Nucleo-C031C6 I2C Example
// Simulation: https://wokwi.com/projects/365421666018061313

#include "LiquidCrystal_I2C.h"
#include <Keypad.h>
#include <Stepper.h>

#define I2C_ADDR    0x27
#define LCD_COLUMNS 20
#define LCD_LINES   4
LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

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] = { A1, A2, A3, A4 }; 
uint8_t rowPins[ROWS] = { 3, 4, 5, 6 }; 

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

const int stepsPerRevolution = 360;
Stepper myStepper(stepsPerRevolution, 10, 11, 12, 13);

const int length = 4;
char password[] = {'1', '2', '3', '4'};
char printedpw[length];
int count = 0;
bool same = true;

void setup() {
  Serial.begin(115200);
  Serial.println("Hello, STM32!");

  lcd.init();
  lcd.backlight();
  lcd.setCursor(0,0);
  lcd.print("pls enter");
  lcd.setCursor(0,1);
  lcd.print("password :");

  myStepper.setSpeed(60);
}

void display() {
  lcd.clear();
  if(same) {
    lcd.setCursor(0,0);
    lcd.print("successfully");
    lcd.setCursor(0,1);
    lcd.print("accessed");
  }
  else {
    lcd.setCursor(0,0);
    lcd.print("password");
    lcd.setCursor(0,1);
    lcd.print("incorrect");
  }
  
}

void loop() {
  char key = keypad.getKey();
  
  if (key != NO_KEY) {
    if (key >= '0' && key <= '9') {
      printedpw[count] = key;
      lcd.print(key);
      count++;
    }
    else if (key == '#') {
      if (count == length) {
        for (int i = 0; i < length; i++) {
          if (password[i] != printedpw[i]) {
            same = false;
            break;
          }
        }
      }
      else same = false;
    display();
    count = 0;
    }
  }
}