Description
The KY-025 Dry Reed Switch Sensor Module is a simple and reliable magnetic sensing module used to detect when a magnet comes close to the sensor.
At the heart of the module is a dry reed switch, which responds to an external magnetic field. This makes the module useful for detecting the opening or closing of doors, movement of mechanical parts, position of objects, and other magnetic triggering applications.
The module includes an LM393 comparator circuit and an adjustable potentiometer that allows the digital switching sensitivity or trigger threshold to be adjusted for the application.
It provides both digital and analog outputs, giving users flexibility when connecting the sensor to microcontrollers. The digital output can be used for simple ON/OFF detection, while the analog output can be monitored by an ADC-capable microcontroller input.
The KY-025 is well suited for Arduino experiments, security systems, robotics, educational electronics, home automation, and DIY sensor projects.
Key Features
- KY-025 magnetic reed switch module
- Dry reed magnetic sensing element
- Detects nearby magnetic fields
- LM393 comparator circuit
- Adjustable sensitivity / trigger threshold
- Built-in adjustment potentiometer
- Digital output
- Analog output
- Onboard indicator LED
- Simple 4-pin connection
- Compatible with common microcontrollers
- Compact PCB design
- Suitable for contactless position detection
Technical Specifications
- Product Type: Magnetic Reed Switch Sensor Module
- Module Model: KY-025
- Sensor Type: Dry Reed Switch
- Comparator IC: LM393
- Operating Voltage: 3.3V–5V DC
- Outputs:
- Digital Output (D0)
- Analog Output (A0)
- Sensitivity Adjustment: Onboard Potentiometer
- Number of Pins: 4
- Typical Pin Configuration:
- VCC – Power Supply
- GND – Ground
- D0 – Digital Output
- A0 – Analog Output
- Detection Method: Magnetic Field
- Microcontroller Compatibility:
- Arduino
- ESP32
- ESP8266
- Raspberry Pi Pico
- STM32
- AVR
- Other compatible development boards
Package Includes
- 1 × KY-025 Dry Reed Switch Magnetic Sensor Module
Applications
- Door and window detection
- Security alarm systems
- Magnetic proximity sensing
- Position detection
- Robotics
- Home automation
- Electronic locks
- Arduino projects
- ESP32 projects
- Raspberry Pi Pico projects
- Mechanical movement detection
- Speed or rotation experiments
- Educational electronics
- DIY sensor projects
Benefits
- Provides contactless magnetic detection
- Simple to interface with microcontrollers
- Supports both analog and digital outputs
- Adjustable digital trigger threshold
- Low-voltage operation
- Compact and breadboard-friendly
- Useful for security and automation projects
- Requires only a small external magnet for detection applications
Why Choose This Product?
The KY-025 Dry Reed Switch Module is an affordable and easy-to-use magnetic sensor for electronics and automation projects. Its combination of a reed switch, LM393 comparator, adjustable sensitivity, and both analog and digital outputs makes it suitable for door sensors, alarms, robotics, position detection, and a wide variety of Arduino and microcontroller projects.




