Description
The KY-031 Knock Sensor Module is a simple spring-based digital sensor designed to detect knocks, taps, vibrations and physical impacts.
When the module is tapped or struck, the internal spring switch momentarily changes state and produces a digital HIGH/LOW signal, making it easy to connect to an Arduino, ESP32 or other microcontroller.
Ideal for tap-activated projects, impact alarms, secret-knock systems, vibration detection and DIY electronics projects.
Product
- KY-031 Knock Sensor Module
- Type: Digital Knock / Tap / Vibration Sensor
- Output: Digital HIGH/LOW Signal
- Sensor Type: Spring-Based Mechanical Switch
- Quantity: 1 Module
- Digital spring-switch detects knocks, taps and impacts
- Simple HIGH/LOW output for easy microcontroller interfacing
- No analogue impact-strength measurement
- Compact module suitable for breadboard and PCB projects
- Compatible with Arduino, ESP32 and similar development boards
- Commonly included in 37-in-1 Arduino sensor kits
What’s Included:
- 1 x KY-031 Knock Sensor Module
- Great For:
- Arduino and ESP32 projects
- Knock and tap detection
- Vibration and impact detection
- Tap-activated switches
- Secret-knock locks and access projects
- Impact and tamper alarms
- DIY electronics and prototyping
Usage Tips:
- Connect the module to a suitable 3.3V or 5V microcontroller supply as appropriate for your board
- Use the digital output to detect a knock or tap
- A tap or impact produces a brief digital signal that can be detected by your microcontroller
- This is a digital spring-switch rather than an analogue piezo sensor, so it detects that a knock occurred rather than measuring how hard it was
- For reliable operation, use suitable software debouncing where required to prevent multiple triggers from a single knock
Ideal for use with Arduino, ESP32 and other compatible microcontroller platforms


