- Mon Jul 22, 2019 1:38 pm
If the output you're getting from the piezo is large enough to register as a logic high, you might be OK with no additional circuitry. (Other than a resistor to limit voltage)
An analog comparator (op-amp) might be a better choice though since you can adjust where your signal begins and noise ends. Plus, you get a nice solid single voltage output from the comparator rather than a varying analog signal.
Give it a try without the comparator, if it works, great! If not, you're probably going to want to build a comparator circuit with an op-amp and use the output from that to trigger your interrupt.
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