Reed Switch (Magnetic Switch)

🧲 Reed Switch (Magnetic Switch) – Normally Open (NO)

The Reed Switch is a small, sealed magnetic switch that opens or closes its contacts in the presence of a magnetic field. It's widely used in door/window security systems, proximity detection, robotics, and automation projects. The switch is normally open (NO) and closes when exposed to a nearby magnet.

⚙️ Technical Specifications

✅ Features

• 🧲 Closes when near a magnet

• 🔒 Used in security systems for detecting door or window open/close

• 📟 Detects magnet movement or presence in robotics and automation

• 🛠️ Easily used with Arduino, ESP32, or Raspberry Pi

• 💡 No power required to operate — purely magnetic switching

• 📦 Compact and reliable with long lifespan

🛠️ Arduino Example Wiring

Use a 10K pull-up resistor between D2 and 5V if needed.

🧪 Example Arduino Code

const int reedPin = 2;
const int ledPin = 13;

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

void loop() {
  if (digitalRead(reedPin) == LOW) {
    digitalWrite(ledPin, HIGH);
    Serial.println("Magnet detected!");
  } else {
    digitalWrite(ledPin, LOW);
    Serial.println("No magnet.");
  }
  delay(500);
}

🎥 YouTube Tutorial