I want to use piezo transducers on digital inputs. I only need On/Off values, and am aware of the need to protect the digital inputs of the Arduino.
Am I right in thinking that in the circuit below: 1) the zener diode should protect the digital input from excess voltages (for 1N4730A, Vz =3.9v) 2) The RC should "debounce" the piezo in the order of 10ms. 3) I've seen suggestion that it might be worth using a schottky diode in paralel with the zener, but I'm not sure whether this is necessary or benficial.
FYI There aren't enough analog pins available, so Knock doesn't solve my problem, and I only want an on/off value from the piezo, and despite lots of time searching and reading threads about drum sensors (which are nothing like my project) I still can't dins an answer.