Grex Micros Conference

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Grex Micros Item 88: Microprocessor controllers and data loggers.
Entered by rcurl on Thu May 19 14:03:46 UTC 1994:

For discussing buying or building, and operating, micro microprocessor
data loggers or controllers.

18 responses total.

#1 of 18 by rcurl on Thu May 19 14:09:48 1994:

I would like to build, or buy and adapt, one of the "micro" micro-
processor boards that are available for under $50, for data logging.
Ive seen them advertised with 8085, 8052 and 8031 processors. I
would prefer a CMOS type for low rest current drain, which can be
programmed/read with a RS232 interface to a PC, with several I/O
lines, etc. The purpose will be remote data logging with the unit
left in place for up to six months, recording the dates and times of
events, and possibly some analog parameters. Therefore the unit
must be asleep most of the time, and wakened at specified times, or
when a random event occurs, to record the date, time and parameter
value. Can anyone here help me to find and adapt a microprocessor for
this?

#2 of 18 by n8nxf on Thu May 19 16:50:22 1994:

find the data sheet to a Motorola HC-11.  If memory serves, these have
an A to D built right into the cip.  They also have RS-232.  The Circuit
Cellar BBS may also be worth a call r.e. this toppic: 203/871-1988.

#3 of 18 by rcurl on Thu May 19 17:42:52 1994:

I have an article about such a data logger from Circuit Cellar Ink, but
one would have to have built a lot of such devices before to make use
of the article. I need Data Loggers for Dummies. But calling the CCI
BBS might be the ticket (unless we have that experience in house).

#4 of 18 by rcurl on Sat May 21 06:20:00 1994:

I posted an inquiry on the CCI BBS. The board seems Ok for posting
messages (in 3 categories), but I didn't find a vast library of
circuits, etc.

#5 of 18 by rcurl on Sun May 29 21:33:34 1994:

I got a response on the CCI BBS to the effect that if there had been
more about the 1990 article in CCI posted to the board, it would have
been posted. I did scan through a few thousand titles. However it 
looks like no one there either knows of complete instructions for that,
or any other, data logger. This is quite strange.

#6 of 18 by kentn on Sun May 29 21:39:43 1994:

Maybe they want you to buy up a lot of back issues where they cover
data loggers for dummies?  Is there a library at UM that carries CCI?

#7 of 18 by mkoch on Mon May 30 16:02:18 1994:

Well, I dunno, if you're looking for real early CCI stuff look through BYTE 
magazine 1980' and earlier.

#8 of 18 by rcurl on Mon May 30 16:14:17 1994:

I don't think they were doing embedded 8031 CMOS controllers then.

#9 of 18 by mkoch on Tue May 31 01:51:10 1994:

Uhh, I think they had a 8031 project, with all the stuff coming later (term,
gfx card, SCSI interface) and then a 8031 multiprocessor project. Could be
that it was a 8051, hmm, nope, well, look it up, maybe it gives you a couple
ideas, maybe not. Nope, seems like it was a 8052, well, similar...
byte  aug 85, jan 84, multiproc oct 88 ff

#10 of 18 by rcurl on Tue May 31 04:35:32 1994:

Thanks. Noted. I'll have a look. Maybe if its specific enough I could
figure out what the CCI 1990 design has as "improvements".

#11 of 18 by mkoch on Tue May 31 12:24:08 1994:

okidoki...

#12 of 18 by kentn on Tue May 31 15:34:54 1994:

Pulled up Mirlyn yesterday and looked at "s=embedded computer" and
got a few hits.  Not sure any of them are what you are looking for,
though (and I expect you've already done this exercise anyway).  At
any rate, there appear to be several embedded processor-type books
in the UM Engineering library that are copyrighted in the last 2-3
years.  This information just *must* be somewhere where we can find
it!

#13 of 18 by rcurl on Tue May 31 20:47:05 1994:

Easy enough for me to look (the Engineering library is downstairs),
but those I've seen before are all theory - how else do you get to
250-350 pages? I'm just looking for parts list and instructions . 
Libraries usually don't keep such practical things.

#14 of 18 by kentn on Tue May 31 23:47:09 1994:

That's what I was afraid of.

#15 of 18 by danr on Fri Jun 3 02:41:27 1994:

You used to be able to find these things advertised in the computer
mags all the time.  How much do you want to spend on this puppy?  I see
one advertised in the March 1994 Byte magazine for $500, but I think
this is probably a little more than you had in mind.

Here's another advertised for $200, but I'm not sure this one has an
A-to-D on it.

#16 of 18 by rcurl on Fri Jun 3 06:17:00 1994:

You can get the 8031 plus I/O on board for ca. $50, but I don't know
how to make it do what I need - if it can. Or, did you mean a complete
mico data-logger? Yes, I have a list of sources, near the $$ you cite.
Generally, too much.

#17 of 18 by danr on Fri Jun 3 12:00:42 1994:

If you have the info on the 8031 board, let me have a look at 
it sometime.  I could determine if it will do what you want.
I used to work for a data logger company and was teh project engineer
on a project that developed a temperature meter based on the 8031/8051.

#18 of 18 by rcurl on Fri Jun 3 14:52:28 1994:

That's great, Dan! I will gather my materials, and bring them to the
board meeting.

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