// UNO - Hello Serial (non-blocking uptime, hemat SRAM)

void setup() {
  Serial.begin(9600);                  // Inisialisasi UART @9600 bps
  Serial.println(F("Hello, Board!"));  // F() => string disimpan di Flash
}

void loop() {
  static unsigned long t = 0;
  unsigned long now = millis();        // waktu sejak boot (ms), berbasis Timer

  if (now - t >= 1000) {               // cek tiap 1000 ms (tanpa delay)
    t = now;
    Serial.print(F("Uptime (ms): "));
    Serial.println(now);
  }
}