Analog Piezoelectric Vibration Sensor

A ceramic piezoelectric disc generates a small voltage whenever it is flexed, so this module responds to knocks, taps and vibration without needing power for the sensing element itself. The board conditions that signal into an analog output that can be read on an Arduino, ESP32 or other microcontroller ADC, with stronger impacts producing higher readings. It is a contact-type sensor, so it works best glued or taped to the surface you want to monitor. Common uses include electronic drum pads, knock-activated locks, impact counters and machine-vibration alarms.