Switch Reed Magnetic Mini Sensor Module

Features

• Simple magnetic proximity detection
• Digital output (HIGH/LOW)
• Built-in pull-up resistor and signal conditioning circuit
• Compact and easy to integrate
• Compatible with Arduino, Raspberry Pi, and other microcontrollers

Specifications

Pinout

Working Principle

When a magnet approaches the glass-encapsulated reed switch inside the module, the reeds are attracted to each other and close the circuit. This change is detected by the onboard circuitry and provided as a digital signal (LOW). When the magnet moves away, the reeds separate, and the output returns HIGH.

Wiring with Arduino

Example Arduino Code

const int reedPin = 2;  // Pin connected to the reed switch
const int ledPin = 13;  // Built-in LED

void setup() {
  pinMode(reedPin, INPUT);
  pinMode(ledPin, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  int sensorState = digitalRead(reedPin);
  if (sensorState == LOW) {
    Serial.println("Magnet detected!");
    digitalWrite(ledPin, HIGH);
  } else {
    Serial.println("No magnet.");
    digitalWrite(ledPin, LOW);
  }
  delay(200);
}

Applications

• Door/window position detection
• Security alarm systems
• Robotics position feedback
• Reed relay triggering
• Speed sensors (when combined with rotating magnets)

Comparison with Similar Sensors

Notes

• Ensure proper orientation of the magnet relative to the sensor.
• Avoid exposure to strong mechanical shocks that may damage the reed tube.
• Use pull-up or pull-down resistors if needed for specific microcontroller configurations.