The Knock Sensor Module

The Knock Sensor Module is a small board with a spring-type knock switch that detects taps, knocks and sudden impacts. When the board is hit, the spring touches its contact and the signal pin changes state for a short moment, which a microcontroller can read as a digital input. It is a simple way to add knock-to-open, tap counters and impact alarms to Arduino and ESP32 projects.

Knock Sensor Module Specifications

• Sensing element: spring-type knock (tap) switch
• Output: digital, a short pulse on each knock
• Pins: 3 (signal, VCC, GND)
• Supply voltage: 3.3 V to 5 V
• Compatible with: Arduino, ESP32, ESP8266 and Raspberry Pi GPIO

Knock Sensor Module Applications

• Secret knock door locks and boxes
• Tap and impact counters
• Shock alarms for packages, doors and windows
• Interactive toys and STEM sensor kits

What's in the Box

• 1 × knock sensor module

Tip: The pulse from a knock is very short, so read the signal with an interrupt or a fast loop rather than a long delay(). Add a short software debounce, as one knock can make the spring bounce several times.

Orders placed before 14:00 are ready for pickup the same day. Delivery across Lebanon usually takes 1–3 working days.