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If you find the notion of adding a high frequency hardware clock
daunting (and I do) you may want to think about using an ADC chip with
a built in clock. The MAXIM MAX186DCPP comes to mind and seems well
suited to your needs. It has 8 single-ended channels (four if
differential), the same 4.096 volts full scale, and does not care how
slow the Stamp is in communicating with it. Both will read temperature
using the LM34 or LM35 to tenths of a degree without any arithmetic.
Downsides are that the 186 is $10 more expensive ($19.69 at Digi-Key)
and that there is yet another learning curve to behold.
I haven't developed code for this chip but the simpler MAX187 required
fewer than 10 lines of PBasic. Perhaps someone on the list has
MAX186 code they could share with you. If not, I would be willing to
give it a try as I have the chip, a prototyping Bread Board and your
choice of a BS2 or BS2p-24! I also have debugged code for displaying
temperature on the LED Terminal AppMod board.
73
Fred, K1IZM
daunting (and I do) you may want to think about using an ADC chip with
a built in clock. The MAXIM MAX186DCPP comes to mind and seems well
suited to your needs. It has 8 single-ended channels (four if
differential), the same 4.096 volts full scale, and does not care how
slow the Stamp is in communicating with it. Both will read temperature
using the LM34 or LM35 to tenths of a degree without any arithmetic.
Downsides are that the 186 is $10 more expensive ($19.69 at Digi-Key)
and that there is yet another learning curve to behold.
I haven't developed code for this chip but the simpler MAX187 required
fewer than 10 lines of PBasic. Perhaps someone on the list has
MAX186 code they could share with you. If not, I would be willing to
give it a try as I have the chip, a prototyping Bread Board and your
choice of a BS2 or BS2p-24! I also have debugged code for displaying
temperature on the LED Terminal AppMod board.
73
Fred, K1IZM
Comments
Good morning, Fred
Thanks for you e-mail. I'm very new at this ADC stuff. I have the Parallax
LTC1298 AppKit with all the code, so I understand and can use a 2-channel
ADC. What I would like to do is to be able to use a 4-channel ADC. I have
the ADC12034 chip from National and Tracy Allen @ ecosystems was kind enough
to send me the code to operate Channel 0. I responded to him with questions
about operating all 4 channels but he has not yet responded. He did tell me
that the 12034 was much more difficult to work with than the LTC1298, which I
am beginning to appreciate.
So, to sum it up, I am looking for a 4-channel chip which is less expensive
than the 12034 to run single ended along with the code to operate it. I have
a spare BOE I am using for this learning procedure, and it has a BS2E, which
is compatible with BS2 code. Once I get all this accomplished, my ultimate
goal is to marry an ADC to my URIO Jr. control board to provide sensor
monitoring/control of external devices. Sort of like reinventing the
thermostat or something.
Thanks again, Fred
Sid - W4EKQ
> suited to your needs. It has 8 single-ended channels (four if
> differential), the same 4.096 volts full scale, and does not care
how
> slow the Stamp is in communicating with it. Both will read
temperature
> using the LM34 or LM35 to tenths of a degree without any arithmetic.
> Downsides are that the 186 is $10 more expensive ($19.69 at Digi-
Key)
> and that there is yet another learning curve to behold.
Don't forget Maxim will give you samples of their products (up to
two) if you ask them.
> I haven't developed code for this chip but the simpler MAX187
required
> fewer than 10 lines of PBasic. Perhaps someone on the list has
> MAX186 code they could share with you.
Try Shaun's Basic Stamp Page. I don't have the url handy, but their
is a link to it on Parallax's site, under Links.
James.