This was a new implementation of the hard disk rotary input project I tried last year, the old one never worked correctly (think the opamp was fried) and I tried some variations on the schematic and user suggestions given on the Instructable ...
by S Crafts
by Origami Video
by TheCookiinCompany
by CraftyLefty
by Jennifer Priest
by Cristina Crochet
by Shree Bhagwati