const long interval =200;
const int ledPin = 13;
unsigned long previousMillis = 0;
int ledState = LOW;

void setup() {
  pinMode(ledPin, OUTPUT);
  pinMode(9, OUTPUT);
  digitalWrite(LED_BUILTIN, HIGH);
}

void loop() {
  unsigned long currentMillis = millis();
  if(currentMillis - previousMillis >= interval){
    previousMillis = currentMillis;
    if(ledState == LOW){
      ledState = HIGH;
    }
    else{
      ledState = LOW;
    }
    digitalWrite(ledPin,ledState);
    digitalWrite(9,ledState);
  }
}