you could also use some max128's or ads7828's if you went the i2c route.

On 9/14/06, Dave Hylands <dhylands@gmail.com > wrote:
Hi Zach,

> I need to make an alarm system that goes off at certain temperature.
> I'm measuring the temperature of the electrolyte (water and acid)
> inside a row of batteries.  I need to measure 16 to 32 batteries over
> a period of a few weeks.
> Can I make the alarm system with gumstix/robostix?   Can either one
> handle that many inputs? Where would I find the temperature sensors?

You should look at the DS18S20 temperature sensor. These use the
Dallas 1-wire interface which means you can connect as many of them as
you want. Each sensor has a unique 64-bit ID.

Sparkfun sells them for $3.95 each:
http://www.sparkfun.com/commerce/product_info.php?products_id=245

Atmel has an Application Note (#318) which describes use the onewire
interface. it includes some sample code (but it will almost certainly
need modifications for use under gcc).

You could also use some type of analog sensor and use a few 4:1 or 8:1
analog muxes (maxim-ic.com has a bunch) to feed into the 8 A/D inputs
on the robostix.

--
Dave Hylands
Vancouver, BC, Canada
http://www.DaveHylands.com/

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