void on(int led){
  digitalWrite(led, HIGH);
}
void off(int led){
  digitalWrite(led, LOW);
}
void toggle(int led) {
  digitalWrite(led, !digitalRead(led));
}



void setup() {
  
}

void loop() {
  on(8);
  delay(500);
  //off(8);
  //delay(500);
  toggle(8);
  delay(500);
}