The KY-021 Magnetic Reed Switch module is a switch that is normally open and gets closed when exposed to a magnetic field, sending a digital signal. Commonly used in mechanical systems as proximity sensors.

Compatible with Arduino, Raspberry Pi, ESP32 and other microcontrollers. For analog output see the KY-025 reed switch.

KY-021 SPECIFICATIONS

This module consist of a small reed switch actuated by a magnetic field, a 10kΩ resistor, and 3 male header pins.

CONNECTION DIAGRAM