Newsgroups: comp.robotics
Path: cantaloupe.srv.cs.cmu.edu!das-news.harvard.edu!news2.near.net!MathWorks.Com!europa.eng.gtefsd.com!howland.reston.ans.net!vixen.cso.uiuc.edu!newsfeed.ksu.ksu.edu!moe.ksu.ksu.edu!osuunx.ucc.okstate.edu!olesun!gcouger
From: gcouger@olesun.okstate.edu (Gordon Couger)
Subject: Re: Need help thermometer to RS232?
Message-ID: <Cx4ICE.LnM@osuunx.ucc.okstate.edu>
Sender: news@osuunx.ucc.okstate.edu (USENET News System)
Nntp-Posting-Host: olesun.agen.okstate.edu
Reply-To: Gordon Couger <gcouger@olesun.agen.okstate.edu>=
Organization: Biosystems and Agricultural Engineering at Oklahoma State Univ.
References: <003302Z02101994@anon.penet.fi> <Cx2z9w.Hnu@news.cis.umn.edu> <Cx3oEL.CpB@osuunx.ucc.okstate.edu> <36ptt7$l6n@gazette.bcm.tmc.edu>
Date: Tue, 4 Oct 1994 00:50:38 GMT
Lines: 28

In article <36ptt7$l6n@gazette.bcm.tmc.edu>,
John C. Edwards <jedwards@bcm.tmc.edu> wrote:
>
>Although I haven't tried it, the Basic stamp that is bandied about has
>a temperature-logging circuit shown on one of the Parallax ads.  It has
>a command to read in a pot (5K-50K), so a thermistor in that range could
>probably be used...if all you're doing is temp --> serial out you could
>even compensate for nonlinearites and oversample a bunch.
>
The basic stamp used a resistor and capictor to charge up and you time
the time it takes to get up to a point that will pull a gate high. I have
never tried it but getting more than one sample very close togeather could
prove chalenging. The problems with this are you have to wait a pretty good
while until the capacitor discharges and the current will heat up the 
resistor. 

If you don't want to sample too often it should work ok. I am not sure 
about the accrucy(sp).

Good luck
Gordon

                            Gordon Couger                            
                            Biosystems & Agricultural Engineering              
                            Oklahoma State University                         
                            114 Ag Hall, Stillwater, OK  74074                 
gcouger@olesun.agen.okstate.edu 405-744-9763 day 624-2855 evenings 
    I do not speak for my employer
