HomeRoast Digest

Topic: Thermocouple? (8 msgs / 154 lines)
1) From: Chris McAvoy
Hi All,
I'm interested in plotting my roast profiles, just for fun, not for profit.
Any thermocouple advice out there? Is there an industry standard way to get
the temperature data onto a laptop? I've built some basic electronics stuff
in the past, and have found thermocouple kits that work with my preferred
brand of microcontroller (the BASIC Stamp from parallax) but wanted to know
what the general consensus was out there.
If for some reason I end up making something that would be useful to others
(software wise), I'd like to work with a thermocouple that people are used
to, rather than building a homebrew one that people would have to adapt to.
Any insight would be very much appreciated.

2) From: Robert Avery
This is a multi-part message in MIME format.
Hi Chris .. I think the most popular thermocouple type is the K-Type =
... I'm sure someone else will chime in with something else. I know =
from my experience ... you would have to come up with some type of A to =
D converter .... but software wise ...don't have a guess ... I know =
someone here has already started a program ... forget right now .... =
sure they will give you feedback. Later,Bob

3) From: Chris McAvoy
Thanks Bob,
I realize now I'm mixing up my terms, I'd really like to know what sort of
data loggers people are using.
On 10/6/05, Robert Avery  wrote:

4) From: blizardj
This is what we use here at CCSN (Community College of Southern Nevada).
If you want to go cheap, you might look at the "Go Link" and Logger Light software.
I haven't personally used this setup, but the full size stuff works really well.
Hope this helps.http://www.vernier.com/John

5) From: Matthew Price
On 10/6/05, Chris McAvoy  wrote:
I looked at the Dallas 1-wire stuff when I was trying to get an idea
of what was available at the lowest level.  There are some really
interesting parts over there and they even have a USB terminator
module that will connect a 1-wire network to your PC.  I'm sure
there's code out there to make a Stamp bit-bang out the 1-wire
protocol as well.  If you hunt around there is a thermocouple reader
already designed from the laptop battery manager chip.
I'm exclusively Linux, and there is a very nice 1-wire USB driver that
drops all the 1-wire network stats to /proc on a fixed interval.  You
could easily hack up a data logger for that.  I don't know what your
skills or preferences are on the software side. I have no idea what is
available for Windows, but it would probably be glitzier, but more
locked down if experience is any guide.
P.S. If money was no object I'd get a Fluke two channel thermometer
for the data-logger piece.

6) From: Chris McAvoy
I'm a big Linux guy, but I think my preferred platform for this is OSX,
which isn't too terribly different other than the lack of a standard serial
Thanks for the info,
On 10/6/05, Matthew Price  wrote:

7) From: Greg Scace
K type is fine I think.  As for dataloggers, I use a Picotech TC-08, which 
can handle 8 thermocouples.  The new ones run off of a USB port.  Mine uses 
a serial port.  Software for mine is a bit rudimentary, but it will provide 
graphical results and the files are easily translated into text files, 
which of course means you can import them into the spreadsheet of your 
choice.  Dunno much about the new USB version's software wrt improvements.
Swangate International is the east coast US distributor for Picotech.
At 10:49 AM 10/6/2005 -0500, you wrote:

8) From: Erik Gilling
chrismcavoy wrote on Thu, 06 October 2005 11:26
The Maxim 6675 http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3149)is a nice SPI thermocouple sensor chip with built in A to D and cold junction compensation.  More for connecting to a microcontroller than a PC.

HomeRoast Digest