Shaft Encoders

[brad sanders]

sasami at blaze.net.au (Ken Stone) was saying...

>>Im trying to figger out how that would be done with available components
>>w/o using servo encoders.. but those WOULD be really nifty if implemented
>
>Has anyone ever considered the usee of surplus stepper motors (ex flopp or 
>hard drive) as shaft encoders?

>The other great shaft encoder to adapt is the arcade video game track ball!

Seems to me the analog "interface" to use stepper motors would be more
trouble than it's worth - especially when you can buy MICE in quantity
10 for like 3 bucks each. One mouse=2 rotary encoders (minus the two
XOR gates needed to derive the clocks), so figger mebbe four bucks for
two shaft encoders.

Besides, all those motors would be HEAVY! Can you imagine even a
"Mini" with all stepper motor shaft encoders?

The problem with either of these approaches is deriving absolute
position. Without further mods you have about ZERO tactile feedback,
and you have no absolute "zero" setting to allow marking white lines
on knobs.