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

const int ROW_NUM    = 4; 
const int COLUMN_NUM = 4;

char keys[ROW_NUM][COLUMN_NUM] = {
  {'1','2','3', 'A'},
  {'4','5','6', 'B'},
  {'7','8','9', 'C'},
  {'*','0','#', 'D'}
};

byte pin_rows[ROW_NUM] = {13, 12, 11, 10};
byte pin_column[COLUMN_NUM] = {9, 8, 7, 6};

Keypad myKeypad = Keypad(makeKeymap(keys), pin_rows, pin_column, ROW_NUM, COLUMN_NUM );

LiquidCrystal_I2C lcd(0x27, 20, 4);

int cursorColumn = 0;
int currentState = 'MainMenu';
int messageState = 0;
char password[4];
char pass[4];

void setup(){
  lcd.init();
  lcd.backlight();
}

void loop(){
  switch(currentState) {

  case 'MainMenu': {
    char keypressed = myKeypad.getKey();
    lcd.setCursor(0,0);
    lcd.print("Select Menu");
    if (messageState == 0) {
      lcd.setCursor(0,1);
      lcd.print("Set Password");
    }
    if (messageState == 1) {;
      lcd.setCursor(0,1);
      lcd.print("Enter Password           ");
    }
    if (messageState == 2) {;
      lcd.setCursor(0,1);
      lcd.print("Set Tempt Threshold         ");
    }
    if (messageState == 3) {
      lcd.setCursor(0,1);
      lcd.print("Set Light Threshold       ");
    }
  }
  }
}