Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!oakhill!bill
From: bill@oakhill.UUCP (bill)
Newsgroups: sci.electronics
Subject: Re: Ultrasonic distance finder
Summary: Don't bother taking one of these apart
Message-ID: <2492@devsys.oakhill.UUCP>
Date: 17 Oct 89 18:35:54 GMT
References: <2900UD130322@NDSUVM1> <14056@well.UUCP> <73734@linus.UUCP>
Reply-To: bill@devsys.UUCP ()
Organization: Motorola Inc., Austin, Texas
Lines: 18
Sender:Bill Craig
Followup-To:ic.electornics
Distribution:usa
Keywords:Ultrasonic range finders

>                 -- Bob <Munck@MITRE.ORG>, linus!munck.UUCP
>For $29.95 at the local giant hardware store/lumber yard (Hechinger's),
>I got a little black box with LCD display that works acceptably for rough
>measurements (displays in feet with one digit after the decimal) of
>room sizes in a house.  It won't handle over about 50' outdoors, though.
>It may not be the learning experience you intended for your project, but
>you could buy one and take it apart.

  Some of us working on a "hobby" robotics group did just this and at 
least the B&D range finder most of the work is done by a chip which is mounted
on the board w/o a package (they must intend n selling a LOT of these units).
Seems to be covered with a lump of epoxy and while it would be possible to
reverse engineer this chip it really wouldn't be the learing experiance you 
intended. A far better way would be to talk to T.I.  or Polaroid applications 
engineer or sales rep. Poloroid makes the ranging device and T.I makes a set of
 "decode" chips to match. This is just the point we are at.  In addition there
 is a Byte "Circut Cellar" which gives the details of some devices based on the 
Polaroid sonar.