How to Use LilyPad Reed Switch: Examples, Pinouts, and Specs

The LilyPad Reed Switch is a magnetic switch designed to be easily integrated into e-textiles and wearable projects. It is part of the LilyPad Arduino ecosystem, a set of sewable electronic components that can be used to build interactive garments and accessories. The reed switch activates when a magnetic field is applied, making it ideal for creating switches in clothing without the need for hard mechanical parts.

• Wearable electronics
• Interactive textile projects
• Proximity detection in soft circuits
• Magnetic door or drawer sensors in fabric-based designs

• Operating Voltage: 3.3V to 5V
• Maximum Switch Current: 0.5A
• Contact Rating: 10W (max)
• Switching Voltage: 100VDC (max)
• Switching Current: 0.5A (max)

1. Sew or connect the + pin to the VCC of your LilyPad Arduino or compatible microcontroller.
2. Sew or connect the - pin to the ground (GND) of your microcontroller.
3. Sew or connect the S pin to a digital I/O pin on the microcontroller.
4. Place a magnet near the reed switch to test its functionality.

• Ensure that the polarity of the connections is correct to prevent damage.
• Avoid placing the switch near strong electromagnetic fields that could trigger it unintentionally.
• Use a pull-up or pull-down resistor on the signal line to ensure a stable reading when the switch is open.

// Define the pin connected to the LilyPad Reed Switch
const int reedSwitchPin = 2;

void setup() {
  // Initialize the reed switch pin as an input
  pinMode(reedSwitchPin, INPUT);
  // Begin serial communication at 9600 baud rate
  Serial.begin(9600);
}

void loop() {
  // Read the state of the reed switch
  int switchState = digitalRead(reedSwitchPin);
  
  // If the switch is closed (magnet is near), print a message
  if (switchState == HIGH) {
    Serial.println("The reed switch is closed.");
  } else {
    Serial.println("The reed switch is open.");
  }
  
  // Small delay to prevent overwhelming the serial output
  delay(200);
}

• Switch does not respond: Ensure that the magnet is close enough to the switch and that the switch is properly connected to the microcontroller.
• False triggering: This can occur if the switch is placed near other electronic components that generate a magnetic field. Relocate the switch or shield it from interference.

• Check connections: Verify that all connections are secure and correctly polarized.
• Use a multimeter: Check for continuity when the switch is activated to ensure it is functioning.
• Debounce the switch: Implement software debouncing in your code to prevent false triggering due to switch bounce.

• Q: Can the LilyPad Reed Switch be washed?

  • A: Yes, but ensure it is completely dry before powering it up.

• Q: How close does the magnet need to be to activate the switch?

  • A: The activation distance depends on the strength of the magnet but is typically a few millimeters.

• Q: Is it possible to use the reed switch with a battery?

  • A: Yes, as long as the battery provides a voltage within the operating range of the switch (3.3V to 5V).