Newsgroups: comp.robotics
Path: brunix!news.Brown.EDU!agate!howland.reston.ans.net!cs.utexas.edu!csc.ti.com!tilde.csc.ti.com!mksol!strohm
From: strohm@mksol.dseg.ti.com (john r strohm)
Subject: Re: 2 circuit design questions
Message-ID: <1994Feb25.171354.13736@mksol.dseg.ti.com>
Organization: Texas Instruments, Inc
References: <8549@falcon.ukc.ac.uk>
Date: Fri, 25 Feb 1994 17:13:54 GMT
Lines: 36

In article <8549@falcon.ukc.ac.uk> jf2@ukc.ac.uk (The Black Baron) writes:
>I have 2 questions about circuit design, and I can't find a completely
>appropriate newsgroup for them (so if anyone knows of one, could they
>point me in it's direction please !)
>
>1. How do I go about producing a programmable variable resistance ?
>   i.e. I want to be able to send either serial, or preferably parallel
>   data to a 'device'/piece of circuit/whatever that will make the
>   device/thing change it's resistance. A computer controlled potentiometer,
>   if you will.

One of the IC manufacturers makes a part that does exactly this.  Check back
issues of "Modern Electronics", in Don Lancaster's column.  This might be
difficult, you being on the wrong side of the puddle and all that, but
"Electronics & Wireless World" probably mentioned the part.  I don't recall
the part number, but someone here will recognize it and post it.


>
>2. How can I multiplex 10 serial lines that each send irregular commands
>   of 2 bytes into a single serial line, and be sure that I don't miss any
>   data on any of the lines (while servicing another line) ?

With great difficulty.  This is called a "statistical multiplexer", and is
a nontrivial piece of hardware and software development.

>
>Anybody got any pointers for me ?!
>
>Thanks for any help,
>
>Black Baron
>aka Julian
>


