Knock threshold adjustment

Hi All,

For my first Arduino project I am making my way through a variation of the Knock tutorial. I have no problems getting the basic circuit setup, but I am wondering if there is a way I could adjust the threshold sensitivity of the piezo sensor on PCB as opposed to having to adjust the value in the software (i.e., the value above which triggers the 'knock')? My first thought was to use a potentiometer as a voltage divider and put it in series with the analog input coming from the piezo (hoping this would allow me to adjust voltage that ultimately makes it to the Arduino), but this doesn't seem to work. Could someone set me straight or perhaps point me to some relevant reference material as to how I might accomplish this?

Thanks in advance!

A piezo element can deliver high voltage spikes that a capacitor in parallel should reduce and enable you to adjust sensitivity with your potentiometer. You'll have to experiment to find the correct value - an oscilloscope would help you visualize what is happening.