Newsgroups: comp.robotics
Path: cantaloupe.srv.cs.cmu.edu!das-news2.harvard.edu!news2.near.net!howland.reston.ans.net!news.sprintlink.net!news.indirect.com!s41.tucslip.indirect.com!user
From: scott@ioinc.tucson.az.us (Scott Forbes)
Subject: Re: SCSI vs. Serial on MAC Plus, etc.
Message-ID: <scott-2404950046100001@s41.tucslip.indirect.com>
Sender: usenet@indirect.com (Internet Direct Admin)
Organization: Internet Direct, indirect.com
Date: Mon, 24 Apr 1995 07:46:10 GMT
References: <3n0cqu$6ph@sundog.tiac.net> <3n4fah$qdm$1@mhade.production.compuserve.com> <Pine.OSF.3.91i.950422103236.18790B-100000@saul2.u.washington.edu>
X-Newsreader: Value-Added NewsWatcher 2.0b24.0+
Lines: 21

In article
<Pine.OSF.3.91i.950422103236.18790B-100000@saul2.u.washington.edu>, Roger
Leger <roger8@u.washington.edu> wrote:

>  This continues my search for wireless. It was written:
> "1) A serial cable is cheaper than a SCSI cable.  (And easy to 
> replace with a couple of ifrared transceivers, later)"
> 
> Is this diffuse wireless infrared, or line of sight?
> What infrared transceivers? HP's are only line of sight.
> 
> thanks for any replies

There's one other way to control a robot with a Mac that may be even
cheaper: the sound output.  I've built a 7-servo arm this way by sending a
string of pulse-width-modulated pulses out of the sound port, demuxed them
with a PAL, and sent the pulses straight into hobby servos.  This is
basically the same way radio-control transmitter/receivers work, so it
would be trivial to broadcast it.

 -- Scott
