Subject: Re: [linux-audio-dev] read it and drool
From: Chris Baugher (baugher_AT_enteract.com)
Date: Tue Dec 05 2000 - 05:18:47 EET
On Tue, 5 Dec 2000, David Olofson wrote:
> On Monday 04 December 2000 18:00, Chris Baugher wrote:
> > On Mon, 4 Dec 2000, David Olofson wrote:
> > >
> > > There are optical high resolution rotary encoders that would be
> > > suitable for this. One of those, a counter chip and a few gates
> > > on a bidirectional parallel port would probably be the easiest
> > > prototype hack. (The counter wrapping at 256 is ok, as you only
> > > deal with deltas. Just read frequently enough to get at least two
> > > readings per full counter cycle.)
> >
> > This is exactly the kind of thing I've been thinking of trying.
> > Where might one find these high resolution encoders you speak of?
>
> Bigger electronic component dealers have all kinds of stuff like
> this; industrial strength joysticks, trackballs, chassis monitors
> etc. Try
>
> http://www.farnell.com
Ok, yeah. I was thinking you had some specific model from some specific
place in mind that you had used before and thought might be good for this
application.:)
Anyway, one issue with encoders is whether to use the absolute or
incremental types. The absolute encoders behave more like potentiometers
in that they "remember" their positions and therefore offer some feedback
as to their current position. Incremental encoders do not and that could
be annoying in some(many?) places.
Also the rotary encoders I have seen don't have position stops like
potentiometers do. (It wouldn't make sense for the incremental variety,
but maybe it would for the absolute).
Thoughts anyone?
Chris|
>
> for example. You'll also find the rest of the stuff you need there.
>
>
> //David
>
> .- M A I A -------------------------------------------------.
> | Multimedia Application Integration Architecture |
> | A Free/Open Source Plugin API for Professional Multimedia |
> `----------------------> http://www.linuxaudiodev.com/maia -'
> .- David Olofson -------------------------------------------.
> | Audio Hacker - Open Source Advocate - Singer - Songwriter |
> `--------------------------------------> david_AT_linuxdj.com -'
>
>
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