The SW-420 Vibration Sensor Module is a high-sensitivity digital switch designed to detect physical shocks, vibrations, and tilt. At Electrapac, we recommend this sensor for students and security enthusiasts in Bangladesh who are building anti-theft alarms, smart vehicle trackers, or earthquake detection prototypes using Arduino and Raspberry Pi.

The heart of this module is the SW-420 vibration switch, which consists of a small metal spring and a conductive pillar inside a sealed tube. In a still state, the circuit is closed (output is LOW). When the module is shaken or moved, the internal spring vibrates and momentarily breaks the circuit, causing the output to go HIGH. It is a reliable, low-cost solution for detecting movement without the complexity of a 3-axis accelerometer.

Key Features for Electrapac Customers

• Adjustable Sensitivity: Features a built-in multi-turn potentiometer. Turn it clockwise to make the sensor more sensitive to tiny vibrations, or counter-clockwise for heavy impact detection.

• Clean Digital Signal: The on-board LM393 comparator ensures a sharp, jitter-free square wave output that microcontrollers can easily read without extra filtering.

• Dual LED Indicators: Includes a red Power LED and a green Status LED that flashes the moment a vibration is detected, making manual calibration easy.

• Non-Directional Sensing: Unlike some tilt switches, the SW-420 can detect vibrations from almost any angle, making it highly versatile for mounting.

• Low Power Consumption: Its tiny current draw makes it perfect for battery-powered IoT security devices that need to remain active for months.

Setting up the Electrapac SW-420 module is straightforward for any DIY project:

1. VCC: Connect to 3.3V or 5V.

2. GND: Connect to the ground.

3. D0 (Digital Out): Connect to an Arduino Digital Pin (e.g., Pin 3).

4. Calibration: Power the module and keep it still. Adjust the potentiometer until the "Signal LED" just turns off. Now, tap the sensor; the LED should blink, signaling a successful trigger.

Pro-Tip: For security applications like a "Window Break Alarm," use the attachInterrupt() function in your Arduino code. This allows the microcontroller to "sleep" and save power, waking up instantly only when the vibration sensor detects a shock.

• Anti-Theft Alarms: Detecting when a motorcycle, bicycle, or laptop bag is moved or tampered with.

• Earthquake Early Warning: Building low-cost home sensors that trigger a siren during seismic activity.

• Smart Appliances: Detecting when a washing machine has finished its cycle based on the stopping of vibrations.

• Impact Logging: Monitoring if a fragile package has been dropped or handled roughly during shipping.

• Object Counters: Detecting vibrations on a conveyor belt to count moving items in a factory setting.

We source our SW-420 Vibration Modules with genuine LM393 chips and high-tensile internal springs to ensure consistent triggering over time. Visit us at www.electrapac.com for the motion-sensing components that add an extra layer of security to your tech.