#define LED 8

void setup() {
  Serial.begin(115200);
  Serial.println("Start!");
  // put your setup code here, to run once:
  pinMode(LED, OUTPUT);
}

int i = 0;
void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(LED, HIGH);
  delay(100);
  digitalWrite(LED, LOW);
  delay(100);
  Serial.println(i++);
}