The tapping parameter analyzer outputs a low-level voltage signal when a tapping signal is detected. A simple circuit can be built using the tapping sensor module and the built-in LED on the module's digital I/O interface to create a tapping flasher. Utilizing the LED on the digital I/O interface, the tapping sensor is connected to the digital I/O interface; when the tapping sensor detects a tapping signal, the LED flashes. Accurate Knock Detection: The KY-031 knock sensor module is designed to detect percussion, tapping, and vibration signals, making it ideal for interactive projects, alarms, and touch-activated systems. Stable Digital Output: Provides a clean digital output signal when a knock or vibration is detected, simplifying code development and reducing the need for complex signal processing. Color: Black Material: plastic Package Contents: 10Pcs KY-031 Knock Sensor Module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.