On Thu, 28 Aug 1997 16:06:55 -0500 Bob Fehrenbach <bfehrenb@EXECPC.COM>
writes:
>I frequently am involved in the design of products having programmable
>parameters.  Up/Down keys are used to set the values.  It is generally
>desireable to allow the user to press and hold Up or Down and to
>make the scroll rate faster, the longer the key is held.
>
>A simplified version of a way to do this:
[method of changing the sampling period deleted]
>
>--

I have used the much simpler approach of using a constant update rate,
but increasing/decreasing the value by more than 1.  The increment value
increases the longer the button is held down up to some maximum.  If the
increment isn't a power of 10, changing by more than 1 isn't noticeable
to the user, since the display is changing too fast to read any but the
most significant digits.  When the value is close they will release the
button and make a fine adjustment in any case, since it isn't possible to
stop a fast-moving value exactly where desired even if it is changing by
ones.