Harold,

Agree completely with you on keeping parts down. KISS should be printed=20
in the forehead of every engineers.  I forgot to look at the dsPic's=20
which have 12-bit A/D's (dsPIC30F3014) and is at almost the same price=20
as the 18F258 which was my original choice.  This is probably the way to=20
go. However I got so interested in this circuit now and can learn a lot=20
from it so I have to test it also I think. :-)

Thanks!
/Ake

Harold Hallikainen wrote:

>The Maxim part (16 bit data acquisition system) was not too bad, as I
>recall. In the thermometer circuit (which uses a precision thermistor), =
I
>use a 0.1% pull-up on the thermistor, then go directly into the A/D. The
>top of the pull-up is the on-chip reference, so reference errors cancel.
>This one part eliminated the need for differential amplifiers and a bunc=
h
>of precision parts. You connect it - it works. I often say "The ideal
>design has zero parts." If you can get one part to do the work of 10, I
>use the one. It may appear cheaper to use the 10 cheap parts, but the
>hassles in getting it to work reliably, deal with adjustments, etc. is
>just not worth it to me. I ended up with a circuit with no adjustments. =
It
>just works...
>
>Harold
>"The ideal design has zero parts."
>
>
> =20
>
>>Harold,
>>
>>I was trying to keep away from 12-bit A/D's due to cost reason. I have
>>the uP and it have a 10-bit A/D. If there are any 12-bit A/D's availabl=
e
>>at a good price oh well its another situation. Suggestions?
>>
>>/Ake
>>   =20
>>
>
>
>
> =20
>


--=20
 ---
Ake Hedman (YAP - Yet Another Programmer)
eurosource, Brattbergav=E4gen 17, 820 50 LOS, Sweden
Phone: (46) 657 413430 Cellular: (46) 73 84 84 102
Company home: http://www.eurosource.se     =20
Kryddor/Te/Kaffe: http://www.brattberg.com
Personal homepage: http://www.eurosource.se/akhe
Automated home: http://www.vscp.org


--=20
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