Reed Sensor Module (Reed Relay) 🧲

The Reed Sensor Module is a compact, magnetically actuated reed switch assembly mounted on a PCB for easy integration with microcontroller platforms. When a magnet approaches the sensor, the internal contacts close, providing a clean digital output ideal for detection in encoders, magnetic key systems, and door/window alarms. Designed for rapid prototyping and reliable deployment, it suits both Arduino and Raspberry Pi-based projects and broader electronics components ecosystems.

Key Features ✨

• Magnetic actuation with a normally open reed contact that closes near a magnet.
• Digital output for straightforward interfacing with Arduino, Raspberry Pi, and other microcontroller modules.
• Onboard LED indicator lights when a magnet is detected.
• Supports horizontal or vertical sensor orientation for flexible installation.
• Excellent for proximity, limit, and position sensing in encoder or magnet-based systems.

Technical Specifications ⚙️

• Interface: 3-pin header — GND, Vcc, DO (Digital Output)
• Supply Voltage (Vcc): 5 V DC (typical)
• Output Level: Logic HIGH (~5 V) when a magnet is present; logic LOW when absent
• Default State: Reed contact is open without a magnetic field; closes when a magnet is nearby
• Indicator: Onboard LED illuminates on magnet detection
• Orientation: Sensor can be mounted horizontally or vertically
• Compatibility: Works directly with 5 V logic (e.g., Arduino). For 3.3 V systems such as Raspberry Pi, use appropriate level shifting or verify module compatibility.

Pinout 📌

• GND: Ground reference
• Vcc: +5 V supply
• DO: Digital output to a GPIO pin on your microcontroller

Orientation and Output 🧭

The reed element can be installed horizontally or vertically to suit your layout. The module provides a digital signal, outputting a logic 1 (5 V) when a magnet is brought near. The onboard LED turns on to visually confirm detection.

Typical Applications 🔧

• Encoders and rotational position sensing
• Door/window alarm and tamper detection systems
• Magnetic key or access detection
• Limit switches in robotics and CNC mechanisms
• Proximity sensing for Arduino, Raspberry Pi, and other electronics modules

Quick Start Wiring 🔌

• Connect Vcc to the 5 V pin on your Arduino (or use appropriate interfacing with 3.3 V systems).
• Connect GND to system ground.
• Connect DO to a digital input pin on your microcontroller.
• Read the pin as a digital input; a HIGH indicates a nearby magnet.

Engineering tip: Reed contacts can exhibit brief contact bounce. For robust designs, add simple debouncing in software or hardware.

Package Contents 📦

• 1 × Reed Sensor Module