int exLED = 0;
int offTime = 250;
int onTime = 750;

void setup() {
  // put your setup code here, to run once:
pinMode(exLED, OUTPUT);
Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(exLED, HIGH);
Serial.println("LED is On");
delay(onTime);
digitalWrite(exLED, LOW);
Serial.println("LED is Off");
delay(offTime);
}