//************************************************
//* ลิงค์ศึกษา https://youtu.be/fuL3fRTxCuk        *
//************************************************


#include <LiquidCrystal_I2C.h>


// Define the LCD I2C interface
LiquidCrystal_I2C lcd(0x27, 20, 4);   //Module IIC/I2C Interface บางรุ่นอาจจะใช้ 0x3f


const byte BUTTON_SET = A0;
const byte BUTTON_UP = A1;
const byte BUTTON_DW = A2;
const byte BUTTON_CANCEL = A3;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  lcd.begin(20,4);

  pinMode(BUTTON_SET, INPUT_PULLUP);
  pinMode(BUTTON_UP, INPUT_PULLUP);
  pinMode(BUTTON_DW, INPUT_PULLUP);
  pinMode(BUTTON_CANCEL, INPUT_PULLUP);
}

void loop() {
  static boolean Display = true;
  static boolean ButtonSet = false;

  if(Display == true){
    Display = false;
    lcd.setCursor(0,2);
    lcd.print("hrllo1");
    lcd.setCursor(0,2);
    lcd.print("hrllo2");
  
  }

  if(digitalRead(BUTTON_SET)==0){
    delay(1);
    if(digitalRead(BUTTON_SET)==0){
      if(ButtonSet==false){
        ButtonSet = true;
        lcd.clear();
        SelectMenu();
        Display = true;
      }
    }
  }else{
    ButtonSet = false;
  }

}


void SelectMenu (void)
{
  boolean Display = true;
  boolean Exit = false;
  boolean ButtonSet = false;
  boolean ButtonUp = false;
  boolean ButtonDown = false;
  boolean ButtonExit = false;

  byte Menu = 0;
  const char MenuText[4][17] = {"1: Menu 1",
                                "2: Menu 2",
                                "3: Menu 3",
                                "4: Menu 4"};

  while(Exit==false){
    if(Display==true){
      Display = false;
      lcd.setCursor(0,0);
      lcd.print("Select Menu 1-4");
      lcd.setCursor(0,1);
      lcd.print(MenuText[Menu]);
    }


    if(digitalRead(BUTTON_SET)==0){
      delay(1);
      if(digitalRead(BUTTON_SET)==0){
        if(ButtonSet==false){
          ButtonSet = true;
          switch(Menu){
            case 0: Serial.print("you 1"); break;
            case 1: Serial.print("you 2"); break;
            case 2: Serial.print("you 3"); break;
            case 3: Serial.print("you 4"); break;
          }
        }
      }
    }else{
      ButtonSet = false;
    }
    //_______________________________________________
    if(digitalRead(BUTTON_UP)==0){
      delay(1);
      if(digitalRead(BUTTON_UP)==0){
        if(ButtonUp==false){
          ButtonUp = true;
          if(Menu<3){
            Menu++;
          }else{
            Menu=0;
          }
          Display = true;
        }
      }
    }else{
      ButtonUp = false;
    }
    //_______________________________________________
    if(digitalRead(BUTTON_DW)==0){
      delay(1);
      if(digitalRead(BUTTON_DW)==0){
        if(ButtonDown==false){
          ButtonDown = true;
          if(Menu>3){
            Menu--;
          }else{
            Menu=0;
          }
          Display = true;
        }
      }
    }else{
      ButtonDown = false;
    }
    //_______________________________________________
    if(digitalRead(BUTTON_CANCEL)==0){
      delay(1);
      if(digitalRead(BUTTON_CANCEL)==0){
        if(ButtonExit==false){
          ButtonExit = true;
          lcd.clear();
          Exit = true;
        }
      }
    }else{
      ButtonExit = false;
    }
    //_______________________________________________





  }
}