boolean toggle = false;
uint8_t pulsePin = 0;

void setup(){
  delay(10000);
  Serial.begin(115200);
  Serial.println("Starting Serial...");
  while( !Serial );
  Serial.println("Serial available!");
  for(uint8_t i = 0; i <= 16; i++){
    pinMode(i, OUTPUT);
    Serial.print("Pin ");
    Serial.print(i);
    Serial.println("as OUTPUT!");
  }
}

void loop(){
  toggle = !toggle;
  digitalWrite(pulsePin, toggle);
  delay(1000);
}