Hi guys, well recently I've been looking for an inexspensive optical encoder for our bot. After some searching I found a pretty nice one and wanted to share it with you guys. It is the ep4 from US digital. What is nice is that you can specify the CPR from 100 to 360 free of charge as well as specify some other options. We decided to go with the low 100 resolution since we don't need it to be very high and to minimize the interrupts to the PIC. Also an important this is that it is cheap at a price of about $20 each! We only need one,but bought two! Be sure to buy a cable with the molex connector unless you have these lying around. If you don't need the quadrature output and dont need to know the direction of rotation you can just use either singal lines A or B to give you a squarewave pulse train.
Here is the link to it!
http://www.usdigital.com/products/e4p/
Hope that this helps!
Windell
#2477