http://www.ar.com.au/~softmark/page46.html
Just a suggestion, this would allow you to use the USB port to interface to a digital source, all you should need is a power supply (actually this board can supply 5V at 100mA, you don't need an extra power supply) and personally, I would just put a spot of good flat white paint on the wheel and use a red led and infrared phototransistor.
Should cost less then $50.00 and work pretty well.
Sigmason
Just a suggestion, this would allow you to use the USB port to interface to a digital source, all you should need is a power supply (actually this board can supply 5V at 100mA, you don't need an extra power supply) and personally, I would just put a spot of good flat white paint on the wheel and use a red led and infrared phototransistor.
Should cost less then $50.00 and work pretty well.
Sigmason