The Hall Effect Sensor Module (A3144) is a specialized magnetic switch that detects the presence of a magnetic field. At Electrapac, we recommend this sensor for makers and students in Bangladesh who are building non-contact switches, tachometers (speed counters), or proximity alarms for their Arduino and ESP32 projects.

Product Overview

The Hall Effect sensor works on the principle that a magnetic field creates a voltage difference across a conductor. This specific module is "digital," meaning it acts like a switch: when a magnet is brought close to the sensor (usually the South pole), the output pin goes LOW. When the magnet is removed, it goes HIGH. It is much more durable than a mechanical switch because there are no moving parts to wear out. 

Key Features for Electrapac Customers

• Non-Contact Switching: Since it detects magnets through plastic, wood, or glass, it is perfect for waterproof or "hidden" switches in your enclosures.

• High-Speed Detection: Capable of switching thousands of times per second, making it the best choice for measuring the RPM (Rotations Per Minute) of fast-moving motors.

• On-Board Comparator: Includes an LM393 comparator and a potentiometer (on some models) to adjust sensitivity and provide a clean, jitter-free digital signal.

• Dual LED Feedback: Features a power light to show the module is active and a signal light that triggers only when a magnet is detected—great for instant troubleshooting.

• Extreme Reliability: Unlike reed switches, which are made of fragile glass, the Hall Effect sensor is a solid-state semiconductor that is resistant to vibration and shock.

Wiring & Arduino Guide

Setting up the Electrapac Hall Effect module is simple. Connect the pins as follows:

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

2. GND: Connect to the ground.

3. DO (Digital Out): Connect to an Arduino Digital Pin (e.g., D2).

4. Magnet Polarity: If the sensor doesn't trigger, flip your magnet over. Most Hall sensors are "unipolar" and only respond to one side of the magnet (typically the South pole).

Pro-Tip: To measure RPM, attach a small neodymium magnet to a motor shaft. Every time the magnet passes the sensor, it sends a pulse to your Arduino. Use the attachInterrupt() function in your code to count these pulses for highly accurate speed measurement.

Primary Applications

• Speedometers & Tachometers: Measuring the speed of bicycle wheels, fans, or motor shafts.

• Door & Window Alarms: Detecting when a door is opened by placing the sensor on the frame and a magnet on the door.

• Limit Switches: Ensuring a 3D printer or CNC machine doesn't move past its physical boundaries.

• Liquid Level Sensing: Using a floating magnet in a tank to trigger the sensor when the water reaches a certain height.

• Brushless DC Motors: Providing feedback for the internal timing of high-end motors.

Why Shop at Electrapac?

We source our Hall Effect Modules with high-sensitivity A3144 sensors to ensure reliable detection even with small or weak magnets. Visit us at www.electrapac.com for the sensing components that give your projects magnetic intelligence.