Dr. Joe wrote:

> You might try using the DalSemi Ibutton / Thermochron.
> www.ibutton.com  It has temp/rtc/ram in a can that fits in a coin
> battery holder and only needs 1 pin to communicate.  10year life on
> Lithium battery in the can.

  And an serial number function too?  That would *really* go down well
with the software developers - a product *guaranteed* to wear out in ten
years!
--
  Cheers,
        Paul B.