#include <LiquidCrystal_I2C.h>

const int btnUp = 2;
const int btnDown = 3;
const int btnRight = 4;
const int btnLeft = 5;

int x = 0; 
int y = 0; 
bool tUp = false, tDown = false, tRight = false, tLeft = false; 

LiquidCrystal_I2C lcd(0x27,20,4);

void setup() {
  lcd.begin(20, 4); 
  pinMode(btnUp, INPUT_PULLUP);
  pinMode(btnDown, INPUT_PULLUP);
  pinMode(btnRight, INPUT_PULLUP);
  pinMode(btnLeft, INPUT_PULLUP);
  lcd.setCursor(x, y);
  lcd.print("X");
}

void loop() {
  if (digitalRead(btnUp) == LOW && !tUp && y > 0) {
    y--;
    tUp = true;
  }
  if (digitalRead(btnUp) == HIGH) {
    tUp = false; 
  }

  if (digitalRead(btnDown) == LOW && !tDown && y < 3) {
    y++;
    tDown = true;
  }
  if (digitalRead(btnDown) == HIGH) {
    tDown = false;
  }

  if (digitalRead(btnRight) == LOW && !tRight && x < 15) {
    x++;
    tRight = true;
  }
  if (digitalRead(btnRight) == HIGH) {
    tRight = false;
  }

  if (digitalRead(btnLeft) == LOW && !tLeft && x > 0) {
    x--;
    tLeft = true;
  }
  if (digitalRead(btnLeft) == HIGH) {
    tLeft = false;
  }

  lcd.clear();
  lcd.setCursor(x, y);
  lcd.print("X");
}