void setup()
{
  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(3, OUTPUT);

  digitalWrite(LED_BUILTIN, LOW);
  analogWrite(3, 0);
}

void loop()
{
  digitalWrite(LED_BUILTIN, HIGH);
  analogWrite(3, 1);
  delay(1000); // Wait for 1000 millisecond(s)
  analogWrite(3, 0);
  digitalWrite(LED_BUILTIN, LOW);
  delay(1000); // Wait for 1000 millisecond(s)
}