byte led_Pin = 4;
int timeOn = 1000;
int timeOff =500;
void setup() {
    // put your setup code here, to run once:
pinMode(led_Pin, OUTPUT);
}
void loop() {
  // put your main code here, to run repeatedly:
//int timeOn = 500;
//int timeOff =500;

digitalWrite(led_Pin, HIGH);
delay(timeOn);

digitalWrite(led_Pin, LOW);
delay(timeOff);
}