> Getting back to my incubator project, I want to build an
incubatotor
>that uses a micro controller that will maintain temperture with in
one
>degree farenhite and use a stepper motor to move the eggs every
couple
>of hours. I would also like to monitor relitive humidity. Would the
>16f84 be a good choice of chips?



The 16F84 would be a good PIC to use due to its ease of
reprogrammability.
However, you want to measure temperature - the 16F84 does not have an
A2D converter. You can interface external A2D's to a PIC with some
additional complexity.

The BASIC Stamp computer is PIC based and has a much easier to learn
language (BASIC) than PIC machine language. HOWEVER, STAMPS are
vastly overpriced, IMHO, and become limiting in capability with time.

For about $US100 you can get the ME labs PICBasic which allows you to
make stamp like devices for much less per each. The language is a
slighly extended form of STAMP BASIC plus you can add PIC assembler
as you need to, and become more experienced.

If money is a significant consideration then a straight PIC plus one
of the very cheap PIC programmers, often mentioned on this list,
would be a good start.

PIC is not the simplest processor family to understand (it has some
very strange programming features related to its development
history.)
For small programs these will (probably) not bother you too much. A
good feature of PICs is this list where you have over 1000 people to
answer your questions :-). PIC is also forgiving from a hardware
point of view. Overall its not a bad hobbyist choice.

Re incubators. Some I have seen use motor driven rotating rods which
the eggs are placed on.
You don't really need a stepper motor for this. Any small geared
motor sufficiently geared down will do with input signals from eg
switches which indicate when eg 1/4 of a turn of the rods has been
made. Much simpler than steppers to start.

Control to 1 degree F is possible but you may need to learn a little
about control principles.


regards

    Russell McMahon