It's good to see this old thread come back to life! As they say "what goes around comes around" (pun intended).
For those of you who want more information, look back at my presentation from the 2012 AAW Symposium. A copy of the hand-out is at:
http://www.billooms.com/Resources/AAW/OomsAAW2012.pdf
Also, see the article I wrote in the June 2011 issue of American Woodturner:
http://www.billooms.com/OrnamentalTurning_AAWJUN11_LR.pdf
(both reprinted by permission of the American Association of Woodturners)
Details of the Indexer Software and mounting a stepper motor can be found at:
http://software.billooms.com/indexer.html
http://cornlathe.billooms.com/indexer.html
This software is no longer supported by me. Apple, Oracle, Microsoft, and Phidgets make changes faster than I can keep up with them.
The source code for this software is available to anyone who wishes to make their own changes or modify it for their own purposes. You can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 3 of the License. It was developed using the NetBeans interactive development environment which is available for free. To download the source code, see:
https://github.com/billooms/Indexer.git (and be sure to read the README file).
There is no good reason to avoid putting a computer in your shop. Our local Habitat for Humanity ReStore sells old refurbished computers for around $50 (including a flat screen monitor). I recently "upgraded" my shop computer to a used (but newer) Mac Mini that I bought on eBay for around $350.
I've considered running the software from a tablet (or smart phone), however the main issue is that on most tablets there is no USB output. You need some kind of output from the tablet to drive the electronics. Yes, there is a USB charger connection, but you generally can't connect some external device (like a printer or a USB thumb drive) to that port. There are only a few newer tablets that have that capability. The Bluetooth/Arduino idea is probably beyond the average woodturner's ability to get working. Furthermore, on Apple tablets and phones you can only run software that you buy through Apple's store. You can't run software that you buy from someone else.
Anyone who is actively building some hardware can email me directly for additional thoughts and comments.
Have fun!
Bill