Jinx wrote...

>I've had a go at your circuit and operation (always in
>the market for more noise)
>
>http://home.clear.net.nz/pages/joecolquitt/davedong.html
>
>but it doesna seem to work as you described. What you
>get is a continuous tone for 1 second. No decay ;-(((
>
>The traces show the ~ 1kHz PIC output and the signal to the
>audio amp
>
>OK (if shorter) for a keyboard beep though
>
>Any ideas for a fixit ? A diode or two ?

Oh, great, now there's a page on the WWW dedicated to "Dave's Dong".
Thanks bunches, Jinx...

I think the problem is you're using RB0 to do the chopping, instead of
RA4 which is what I had; RB0 pulls both high and low, whereas RA4 is
open-drain.

If you really need to use RB0 (I see you're already using RA4 for
something), you could put a diode in series with it (pointing toward the
PIC), as you said. =20

Cheers,

DD

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