AVR-Chat

--- In AVR-Chat@yahoogroups.com, Ralph Hilton <ralph@r...> wrote:

> Connect [the piezo buzze ] between
> 2 output pins and switch them
> alternately. That effectively
> doubles the voltage.

We're talking about a buzzer, here, not a speaker. You just apply a 
voltage and the buzzer does the rest using an internal oscillator.

I think we should start this thread again.  I don't have much to 
suggest except to say that the piezo buzzers I bought from All 
Electronics are too loud and I leave the tape over the hole!

Is the OP sure that both systems are running from the same supply 
voltage? Does he have a voltmeter to measure the voltage across the 
buzzer when it is on?

Graham.