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:

if(timeDelay<=1000){
  delay(3000);
  timeDelay=1000;
}else
timeDelay = timeDelay -100;
digitalWrite(pinLed, HIGH);
delay(timeDelay);
digitalWrite(pinLed, LOW);
delay(timeDelay);
}