#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 20, 4);

int pole[4][5];
int cas = 0; 

void setup() {
  lcd.init();
  lcd.backlight();
  Serial.begin(9600);
  
  // Initialize the positions of the stars in the first row
  for (int i = 0; i < 5; i++) {
    pole[0][i] = random(0, 20);
  }
}

void loop() {

  if (millis() >= cas) {
    lcd.clear();

    for (int y = 0; y < 4; y++) {
      for (int i = 0; i < 5; i++) {
        if (pole[y][i] >= 0) {
          lcd.setCursor(pole[y][i], y);
          lcd.print("*");
        }
      }
    }

    for (int y = 3; y > 0; y--) {
      for (int i = 0; i < 5; i++) {
        pole[y][i] = pole[y - 1][i];
      }
    }

    for (int i = 0; i < 5; i++) {
      pole[0][i] = random(0, 20);
    }

    cas += 500;
  }
}