//LCD config
#include <Wire.h> 
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27,20,4);  //sometimes the LCD adress is not 0x3f. Change to 0x27 if it dosn't work.

uint8_t arrow[8] = {0x0, 0x04 ,0x06, 0x1f, 0x06, 0x04, 0x00, 0x00};

//Variables for the menu encoder
int counter = 0; 
int page=1;
int Ready=1;
int submenu=0;
int last_counter = 0; 
bool clk_State;
bool Last_State; 
bool dt_State;  
int pushed = 0;

//The pin for the push button
#define push 10

void setup() 
{
  pinMode (push,INPUT);       //Define the pin as input
  
  lcd.init();                 //Init the LCD
  lcd.backlight();            //Activate backlight
  lcd.createChar(1, arrow);   //Create the arrow symbol
  lcd.home();                 //Home the LCD
  
  PCICR |= (1 << PCIE0);    //enable PCMSK0 scan                                                 
  PCMSK0 |= (1 << PCINT0);  //Set pin D8 trigger an interrupt on state change. 
  PCMSK0 |= (1 << PCINT1);  //Set pin D9 trigger an interrupt on state change.  
  DDRB &= B11111100;        //8, 9 as input for the encoder clock and data pins

  Last_State =   (PINB & B00000001); //pin 8 state (clock pin)? 
  
  //Prepare the DFplayer module comunication and settings  
  Serial.begin(115200);  
 
  //Print the initial text. Delete these lines if you don't want that
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.write(0);  
  lcd.print("   ARCELIK  ");
  lcd.write(0);
  lcd.setCursor(0,1);  
  lcd.print(" ELEKTRONIK MTY ");
  delay(2000);

  //Print the first page menu.
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.write(1);  
  lcd.print("ACI KONTROLU");
  lcd.setCursor(0,1);  
  lcd.print(" PARAMETRE GIRISI");
}

void loop() { 
  
  if((last_counter > counter) || (last_counter < counter)  || pushed) //Only print on the LCD when a step is detected or the button is pushed.
  {
    Ready=1;

    //Menü ilk sayfası
    if(submenu == 0)
    {  
      if(0 <= counter && counter < 5)
      {
        lcd.clear();
        lcd.setCursor(0,0);
        lcd.write(1);  
        lcd.print("ACI KONTROLU");
        lcd.setCursor(0,1);  
        lcd.print(" PARAMETRE GIRISI");
        page=1;
        pushed=0;
      }
    
      if(5 < counter && counter < 10)
      {
        lcd.clear();
        lcd.setCursor(0,0);
        lcd.print(" ACI KONTROLU");
        lcd.setCursor(0,1);
        lcd.write(1);   
        lcd.print("PARAMETRE GIRISI");
        page=2;
        pushed=0;
      }
      
      if(10 < counter && counter < 15)
      {
        lcd.clear();
        lcd.setCursor(0,0);
        lcd.write(1);  
        lcd.print("BASLAT");
        page=3;
        pushed=0;
        }       
  }//submenu = 0;

    //menü ikinci sayfası
    if(submenu == 1)
      {  
        if(0 <= counter && counter < 5)
        {
          lcd.clear();
          lcd.setCursor(0,0);
          lcd.write(1);  
          lcd.print("Latte");
          lcd.setCursor(0,1);  
          lcd.print(" Cappuccino");
          page=1;
          pushed=0;    
        }
      
        if(5 < counter && counter < 10)
        {
          lcd.clear();
          lcd.setCursor(0,0);
          lcd.print(" Latte");
          lcd.setCursor(0,1);
          lcd.write(1);   
          lcd.print("Cappuccino");
          page=2;
          pushed=0;      
        }
      
        if(10 < counter && counter < 15)
        {
          lcd.clear();
          lcd.setCursor(0,0);
          lcd.write(1);  
          lcd.print("Americano");
          lcd.setCursor(0,1);  
          lcd.print(" Back");
          page=3;
          pushed=0;      
        }
      
      }//submenu = 1
  }//end of the MENU prints on the LCD

  last_counter = counter; //Save the value of the last state

//Now we detect when we push the button
if(digitalRead(push))
  {
     if(submenu == 1)
    {    
       if(page==1)
       {
        submenu=0;
        counter=1;
        pushed=0;
        Ready=0;
       
        lcd.clear();
        lcd.setCursor(0,0);
        lcd.write(1); 
        lcd.print("ILERI");
        lcd.setCursor(0,1);  
        lcd.print(" GERI");
        delay(10000);
       }
    
       if(page==2)
       {
        submenu=0;
        counter=0;
        pushed=0;
        Ready=0;
        
        lcd.clear();
        lcd.setCursor(0,0);
        lcd.print("DENEME");
        lcd.setCursor(0,1);  
        lcd.print("      Wait      ");
        delay(10000);
       }
    
       if(page==3)
       {
        submenu=0;
        counter=0;
        pushed=0;
        Ready=0;
        
        lcd.clear();
        lcd.setCursor(0,0);
        lcd.print("Making coffee...");
        lcd.setCursor(0,1);  
        lcd.print("      Wait      ");
        delay(10000);
       }
    
       if(page==4)
       {
        submenu=0;
        counter=0;
        pushed=0;
        Ready=0;
        
        lcd.clear();
        lcd.setCursor(0,0);
        lcd.print(" Going back...  ");
        lcd.setCursor(0,1);  
        lcd.print("      Wait      ");
        delay(10000);;
       }
    }//end of submenu 1

if(submenu == 0 && Ready==1)
    {    
       if(page==1)
       {
        submenu=1;
        counter=0;
        pushed=1;
        
        delay(500);
        
       }
    
       if(page==2)
       {
        submenu=2;
        counter=0;
         
        pushed=1;delay(500);
       }
    
       if(page==3)
       {
        submenu=3;
        counter=0;
       
        pushed=1;delay(500);
       }
    
    }//end of submenu 0
}
  //Add limit for the counter. Each line of the menu has 5 points. Since my menu has 4 lines the maximum counter will be from 0 to 20
  //If you add more lines for the menu, increase this value
  if(counter > 15)
  {
    counter=15;
  }
  if(counter < 0)
  {
    counter=0;
  }
}//end void

//Interruption vector
ISR(PCINT0_vect){
  
  clk_State =   (PINB & B00000001); //pin 8 state, clock pin? 
  dt_State  =   (PINB & B00000010); 
  if (clk_State != Last_State){     
     // If the data state is different to the clock state, that means the encoder is rotating clockwise
     if (dt_State != clk_State) { 
       counter ++;
     }
     else {
       counter --;
     } 
   } 
   Last_State = clk_State; // Updates the previous state of the data with the current state
}