>> I did a search thru the archives and found David Horn's comments about 
>> using two pins to do a push-pull setup thru some HC invertors.  I assume 
>> thats still a valid and easy way to drive it.  I was hoping also to come 
>> across some references to an inexpensive and small element that still 
>> gives a good 'beep' when driven.  Presently the system voltage is 5V but 
>> could be migrating to 3.3V soon.  So anyone have some good suggestions or 
>> references to what they have used in the past?


I don't know about particular transducers. For the one project in which I 
used this technique, although without the inverters, I was using repurposed 
piezo transducers (as well as the display and case) from a small digital 
alarm clock. IIRC my circuit simple drove the piezo differentially through a 
pair of resistors. The R's, along with the parasitic diodes on the PIC pins 
are to protect the PIC from potential high voltages that will appear on the 
piezo at resonance.

[And yes, I know I shouldn't depend on the parasitic diodes, but...]

--- Bob Ammerman
RAm Systems



-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist