const int pinLED=8;

void setup() {
  // put your setup code here, to run once:
pinMode(pinLED, OUTPUT);
}
int timeDelay=1000;

void loop() {
  // put your main code here, to run repeatedly:
timeDelay=timeDelay-100;

if(timeDelay<=0){
timeDelay=1000;
}
digitalWrite(pinLED, HIGH);
delay(timeDelay);
digitalWrite(pinLED, LOW);
delay(timeDelay);
}