void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, STM32!");
  pinMode(PA13, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  delay(10); 
  digitalWrite(PA13, HIGH);
  delay(1000);
  digitalWrite(PA13, LOW);
  delay(1000);
}