Hello. I have been reading on linux kernel development and device drivers for a while. I feel ready to give it a go. I would like to write a driver for a, preferably usb (otherwise pci), device for a desktop computer. But every device I seem to think of is already supported (including everything I own atm). So, would welcome any suggestions.

P.S. Willing to buy it, provided it's under £100 (150$).