#include <LiquidCrystal_I2C.h>  


// define LED display
#define I2C_ADDR    0x27    
#define LCD_COLUMNS 16                              
#define LCD_LINES   2  

// create led display with defined parameters
LiquidCrystal_I2C lcd(I2C_ADDR,LCD_COLUMNS, LCD_LINES);

// define LED pins
int GreLED = 9;
int RedLED = 8;

// define button pins
int RedButton = 3;
int GreButton = 2;

// other variables
int theVariable = 0;

void setup() {
  // put your setup code here, to run once:
  // initialize LED Display
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0,0);
  lcd.print("   *MY  MENU*   ");  
  delay(1000);

  pinMode(GreLED, OUTPUT);
  pinMode(RedLED, OUTPUT);
  pinMode(GreButton, INPUT_PULLUP);
  pinMode(RedButton, INPUT_PULLUP);

  attachInterrupt(digitalPinToInterrupt(GreButton), menuUp, FALLING);
  attachInterrupt(digitalPinToInterrupt(RedButton), menuDown, RISING);

  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  if (digitalRead(RedButton) == 0) {

    theVariable = 1;

  } else if (digitalRead(GreButton) == 1) {

    theVariable = 2;
  }
  if (theVariable = 1){

    menuDown;

  } else if(theVariable = 2){

    menuUp;

  }
}


void menuUp(){

  digitalWrite(GreLED, HIGH);
  digitalWrite(RedLED, LOW);
  //lcd.setCursor(1,0);
  //lcd.print("*  START TOO   *");
  theVariable = 0;

}
void menuDown(){

  digitalWrite(RedLED, HIGH);
  digitalWrite(GreLED,LOW);
  //lcd.setCursor(1,0);
  //lcd.print("*  MAIN Won  *");
  theVariable = 0;

}