Some users report issues with connecting the scanner to their computer systems. They receive an "Unknown Device" message instead of seeing the Arduino or camera driver.
If this is happening to you, you may be trying to connect the scanner through a USB hub. Hubs are extra USB port outlets. Unfortunately, they mask the ID of the devices plugging into them. You will need to plug the USB directly into your computer through a main USB port in order for the software to recognize the scanner.
Note: Some laptops use internal hubs to expand the number of USB ports available. The same masking of ID will happen. If you get this message while using your computer or laptop, try plugging into a different USB port on your laptop and attempt to connect again.