code: func (d *Driver) Halt() (err error) {
  	// send a landing command when we disconnect, and give it 500ms to be received before we shutdown
  	d.Land()
  	time.Sleep(500 * time.Millisecond)
  
  	// TODO: cleanly shutdown the goroutines that are handling the UDP connections before closing
  	d.cmdConn.Close()
  	d.videoConn.Close()
  	return
  }
docs: // Halt stops the driver.