Hello again

> Agrico LTX wrote:
You are welcome to use Roland <g>
> >
> > Hello everyone...
> >
> > There has been a recent discussion on using piezo buzzers on logic
pins...
> > I was unaware of of the whole capacitive loading problem etc. etc., but
> > find it very interesting. One thing that I have done to increase the
output
> > volume of the buzzer moderately is to connect both piezo terminals to
> > output bins,  and then to pull one pin high whilst pulling the other
low
> > (and vice versa).  This gives you ~10V accross the buzzer, if your pic
is
> > running at 5 V.
> >
> > Cheers
> >         Roland
> Eh?
> How'd you do that?
Sorry, that was probably badly explained (bins?? -> pins!!)
> I tought the PIC's only give +5v or 0V out? Or are you alternating the
> polaties in a voltage-doubler kind of way?
They do only give 5V....

Instead of connecting the one piezo terminal to ground, and the other to
the pic (and then pulling that high & low), connect each piezo terminal to
a different pic pin. Then pull one pin high and the other low, and switch
(other pin high and other pin low):

                 +5V
             <--------
+5V  -----Piezo-----  0V

                -5V
             <------
0V -------Piezo ----  +5V

I hope there aren't any alignment problems above. As shown, one moment
there is +5V  across the piezo, the next moment there is -5V. A difference
of 10V. As opposed to

0V ----Piezo----- 5V

&

0V-----Piezo-----0V

giving a 5V difference...

Cheers
        Roland