Knock IOT sensor module and a digital 13 interface, built-in LED build a simple circuit to produce percussion flasher. Interface comes with digital LED, will knock sensor connected digital 3 interface, when percussion sensor senses measure to percussive signals, LED flashing light. The knock sensor, detects the knocks and the taps. It can work like a switch. The sensor sends data momentarily to the board. To keep the LED on, the button state change codes should be used. So the sensor will work as a switch.