#define LED 2

void setup() {
  // Set pin mode
  pinMode(LED,OUTPUT);
}

void blinkled(uint8_t myled, int duration) {
  digitalWrite(myled,HIGH);
  delay(duration);
  digitalWrite(myled,LOW);
}

void loop() {
  blinkled(LED, 500);
  delay(500);
  blinkled(LED, 250);
  delay(250);
// you can set the delay time by adjusting the parameter of delay();

}