Hi @Wai32961,
A piezo is an electronic device that generates a voltage when it’s physically deformed by a vibration, sound wave, or mechanical strain. Similarly, when you put a voltage across a piezo, it vibrates and creates a tone. Piezos can be used both to play tones and to detect tones.
It won’t create enough voltage to illuminate an LED… Although something such as an Arduino could be used to sense the output of it. Here is a tutorial:
