Newsgroups: comp.robotics
Subject: Re: PIC chips
From: robin.hunziker@mecheng.fullfeed.com (Robin Hunziker)
Path: brunix!cat.cis.Brown.EDU!agate!library.ucla.edu!europa.eng.gtefsd.com!howland.reston.ans.net!vixen.cso.uiuc.edu!uwm.edu!daffy!uwvax!gorgon!fullfeed!mecheng!robin.hunziker
Distribution: world
Message-ID: <af.5236.33.0NAF7C32@mecheng.fullfeed.com>
References: <2q945q$2uo@acme.gatech.edu>
Date: Fri, 13 May 94 08:58:00 -0600
Organization: MechEng / American Society of Mechanical Engineers
Lines: 22


GT RS-485 ? that like a 5v RS-232 if so your in business. I'm using
  the emp20 programmer with the pic16, but they have some 40 pin
  uControllers that might interest you. My biggest hassle right now is
  finding decent 3x4 matrix keypads to talk to the things, the ones
  I've got now are cheap & flimsy.

Rick, EIA-485 (formerly known as RS-485) is an enhancement to EIA-422
that permits multi-drop nodes.  Because of that and its long distances,
it's used alot in industrial applications to allow smart devices to talk
to each other.  IEEE 1118 Bitbus, Modbus, Profibus and Optomux are all
based on EIA-485.  LonTalk and CAN can be run atop EIA-485, but usually
are not.

Regarding keypads, one of the developers of our in-house card reader
looked around at different 4x4 keypads and settled on Grayhill.  The
keypads are used by drivers loading gasoline and diesel and therefore
take alot of abuse.  So far, the Grayhills have been very dependable.
He felt that the stainless-steel Storm keypads were excellent for their
price, but the legends on the keys cannot be easily changed whereas the
Grayhills have interchangeable caps.

