Reed Magnetic Sensor

Description

Reed Magnetic Sensor

A reed magnetic sensor is a switch sensitive to magnetic fields. It consists of two metal contacts sealed inside an airtight glass tube. When a magnet approaches, the contacts close and allow current to flow. It is commonly used for proximity detection and security applications.

Detailed specifications

• Operating voltage: 3.3–5 V DC
• Output: Digital (open/closed circuit)
• Dimensions: Vary by model; generally small and compact
• Main component: Reed switch sealed inside an airtight glass tube

How it works

The reed sensor uses a switch sealed inside a glass tube. In the presence of a magnetic field, the internal contacts close, creating a closed circuit that a microcontroller can read as a digital output.

Applications

• Security and alarm systems
• Proximity detection for doors and windows
• Liquid-level sensors
• Contactless-control projects
• Interactive art installations

Pinout

A typical reed sensor has two leads (contacts) and no designated pins:

1. Lead 1: Connect to a power supply or microcontroller input
2. Lead 2: Connect to ground or a microcontroller output

How to use it

Connect the two leads of the reed sensor as follows:

1. Lead 1 to 5 V or an Arduino digital input
2. Lead 2 to GND or an Arduino digital output

Using it with an Arduino Uno

Basic Arduino code example

const int led = 13; // LED sur l'Arduino
const int reedPin = 3; // Interface numérique du capteur Reed
int reedState; // Etat du capteur Reed


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


void loop() {
  // Lecture de l'état du capteur Reed
  reedState = digitalRead(reedPin);
  if (reedState == HIGH) {
    digitalWrite(led, HIGH);
    Serial.println("Magnet detected");
  } else {
    digitalWrite(led, LOW);
    Serial.println("No magnet");
  }
  delay(100);
}

What the code does: It reads the reed sensor’s digital value, turns on the Arduino LED when a magnetic field is detected, and displays the status in the serial monitor.

Components required for the basic example

• Arduino Uno
• Reed magnetic sensor
• Connecting wires

Basic code explained

1. Pin initialization: The LED pin is set as an output and the sensor pin as an input.
2. Reading and displaying data: The sensor’s digital value is read and displayed in the serial monitor. The LED turns on when a magnetic field is detected.

Basic wiring

• Lead 1 (sensor): D3 (Arduino)
• Lead 2 (sensor): GND (Arduino)

Keywords: switch, magnetic, sensor, reed switch, magnetic detection, Arduino, proximity, security.