#include <LiquidCrystal_I2C.h>
 #define I2C_ADDR    0x27
#define LCD_COLUMNS 20
#define LCD_LINES   4
LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

 #define clk 2
 #define data 3
  
 int counter = 0; 
 int State;
 int LastState;  
 
 void setup() { 
  lcd.init();
  lcd.backlight();
  //Define the pins as inputs
   pinMode (clk,INPUT);
   pinMode (data,INPUT); 
  
   Serial.begin (9600); //Start serial com so we could print the value on the serial monitor
   // Reads the initial state of the clock pin
   LastState = digitalRead(clk);   
 } 
 void loop() { 
   State = digitalRead(clk); // Reads the "current" state of the clock pin
   // If the previous and the current state of the clock are different, that means a step has occured
   if(State != LastState){     
   // If the data state is different to the clock state, that means the encoder is rotating clockwise
     if (digitalRead(data) != State) { 
       counter = counter+1;
     }else{
       counter = counter-1;
     }

    lcd.setCursor(3, 0);
     lcd.print("Position:");
     lcd.println(counter);
     Serial.print("Position: ");
     Serial.println(counter);
   } 
   LastState = State; // Updates the previous state of the clock with the current state
 }