You wrote... >let me give this a try - thanks You're welcome. One thing you might try is to hook up your piezo to the output of an audio signal generator and sweep the frequency around until you find the loudest output; then replicate this same frequency with your PIC. Worked for me... Dave -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu