void setup() {
  // put your setup code here, to run once:
  pinMode(11, OUTPUT);
  Serial.begin(115200);
}

void loop() {
  // put your main code here, to run repeatedly:
  static int16_t blinkTime = millis();
  int16_t now = millis();
  int16_t diff = abs(now - blinkTime);
  if(diff == 250) {
    blinkTime = now + 250;
  }
  analogWrite(11, diff);
  Serial.println(diff);
  Serial.flush();
}