docs: public void run() {
          while (!exiting) {
              if (!queue.isEmpty()) {
                  // wait for a small interval before attempting next transmission
                  try {
                      String data = queue.take();
  
                      if (serial.isOpen()) {
                          serial.write(data);
                          serial.flush();
                      }
  
                      Thread.sleep(delay);
                  } catch (IOException ioe) {
                      ioe.printStackTrace();
                  } catch (InterruptedException e) {
                      //e.printStackTrace();
                  }
              }
          }
      }