The KY031 is a simple and reliable knock sensor module designed to detect physical impacts, taps, and vibrations. It is ideal for projects requiring shake or knock detection, such as interactive installations, security systems, and doorknock sensors [citation:9].
| Parameter | Value |
|---|---|
| Operating Voltage | 3.3V to 5V DC [citation:6][citation:9] |
| Output Type | Digital (HIGH / LOW) [citation:2][citation:11] |
| Default Output State | HIGH (LOW on detection) [citation:2] |
| Dimensions | ~27mm x 15mm [citation:5][citation:12] |
| Hole Fixing | Bolt holes for easy installation [citation:11] |
The module consists of a spring and a center post. When a vibration is sufficient, the spring moves and momentarily shorts the two contacts, generating a signal pulse [citation:4]. Its sensitivity can be adjusted based on the mounting position [citation:4].
√ 3-pin interface with VCC, GND, and Signal.
√ Includes an on-board indicator LED (usually on Pin 13).