title: List machine's serial ports
body: <p>I have an Arduino-based device which connects through USB.</p>
  
  <p>I'd like to detect it from my Qt 4 application, using <code>QExtSerialPort</code> (or whatever necessary), when it's plugged in. </p>
  
  <p>If this weren't possible, I thought I could somehow get a list of the system's port names and just try all of them in search for my Arduino (where I'd implement some kind of handshaking procedure for it to detect it correctly). My concern in this approach is that I'm not sure if a device (for example, printer) would get damaged if I send some kind of handshaking ack at a different baud rate.</p>
  
  <p>So, I don't really know where to start for any of them. Which would be the best approach? How would I implement it?</p>