> There are many possible solutions, but simple "ovening" and a half
> tolerable crystal to start would be a lot easier than many other
> solutions.

This was my thought too. Stick the whole electronics unit inside a thermos =
flask, with a suitable resistor for heating. When synchronising at the begi=
nning of the event the unit could be attached to a suitable mains based pow=
er source, and the heating resistor run for long enough to get the internal=
s to a stable temperature. This should hold the temperature to a much close=
r tolerance than the total temperature range originally given.=20

If it is possible to have the unit powered from a car battery or other 'rel=
atively beefy' power pack (which you may need any way to run 7-segment disp=
lays for 8 hours) then a simple temperature control can be implemented to k=
eep the unit with 10 degrees easily, without too much extra current draw.
--=20
Scanned by iCritical.

--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.