private void OnTriggerEnter(Collider other)
 {
     if (other.gameObject.tag == "StartArea")
     {
         UIOpenDoor doorScript = doorController.GetComponent <UIOpenDoor>();
         doorScript.ToggleDoor();
     }
 }
 private void Start()
 {
     arduino    = ArduinoController.GetComponent <SendMsgArduino>();
     doorScript = doorController.GetComponent <UIOpenDoor>();
 }