const int pinLED = 8;

void setup() {
  pinMode(pinLED, OUTPUT);
}
int timeDelay = 1000;
void loop() {
  timeDelay = timeDelay -100;
  if(timeDelay <= 0 ){
    timeDelay = 1000;
  }
  digitalWrite(pinLED, HIGH);
  delay(timeDelay);
  digitalWrite(pinLED, LOW);
  delay(timeDelay);
}