Mike M wrote:

> I understand how to overcome the problem and why it acts like that,
> but i ask, basic stamp book says use a 40ohm speaker..will that really
> make that much of a differnce in sound from a small wisper to a decent
> volume?

  If you are going to drive the speaker directly from the PIC pin, you
want to operate the PIC within specifications for one thing, which means
about 20mA at 5V.  This corresponds to 250 ohms.  If you are using a
capacitor in series and presuming this capacitor remains charged on
average to 2.5V, then you can use 125 ohms.  If you "stretch the limits"
a trifle, 40 ohms.

  Given that you are going to use a 40 ohm load on the PIC, you can do
this either by a 40 ohm speaker, or an 8 ohm speaker with a 33 ohm
resistor.  Obviously the latter will give only 1/5 the power.

  If you put too low a load onto the PIC, all sorts of odd things may
happen.  You need a CRO to tell what is *actually* happening in any
given situation.

  If you have set the bit by the TRIS register to be an output, the PIC
will pull up and down equally, so you don't need a pull-up (except for
port B.4).  Don't know why this was suggested.

  Do test your code with a CRO on no load to check that it actually does
what you think it does.
--
  Cheers,
        Paul B.