Hello all,
after my series of posts in my blog about photointerrupters and rotary encoders I wrote another post with a practical example: a winding machine. This is a simple homebrew construction but it makes winding a coil comfortable and you can be sure that the number of turns of your coil is correct.
If interested look here:
http://heliosoph.mit-links.info/make-your-own-winding-machine
Here are the other posts of the series:
about photointerrupters:
http://heliosoph.mit-links.info/photointerrupter-basics
http://heliosoph.mit-links.info/photointerrupter-schematic-details
about rotary encoders:
http://heliosoph.mit-links.info/make-your-own-rotary-encoder
http://heliosoph.mit-links.info/make-your-own-quadrature-rotary-encoder
http://heliosoph.mit-links.info/rotary-encoder-software-for-arduino
Hope it helps
Elektrix