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Home / Sensors / Keyes Hall Switch Magnetic Sensor A3144 Speed Measurement Counting Module Compatible with Arduino micro:bit

Attributes

Brand -
Category Robotics / STEM Teaching Tools / Sensors
Origin -
Model Number A3144
Operating Voltage 3.3V - 5V DC
Output Type Digital Switch (Open Collector)
Compatibility Arduino, micro:bit, Raspberry Pi
Sensing Range Approx. 10mm
LED Indicator Yes (Power and Output Status)
Mounting Hole Diameter 3mm
PCB Dimensions 32mm x 14mm
Application Speed Measurement, Counting, Position Detection
Package Includes 1x Hall Sensor Module

6 reviews

A

Anonymous

Mar 22, 2026

Rating: 4/5

Easy to use for beginners

As someone new to electronics, I found this very straightforward to connect. The three pins are clearly labeled. Just remember you need a pull-up resistor if your board doesn't have one internally.

A

Anonymous

Mar 18, 2026

Rating: 5/5

Solid build quality

The PCB looks clean and the soldering is good. No issues with noise or false triggers in my testing environment. Highly recommended for hobbyists.

A

Anonymous

Mar 17, 2026

Rating: 4/5

Great value for learning

Bought this for a school project involving the micro:bit. It was easy to wire up and detect magnets. Only giving 4 stars because the documentation could be slightly better, but plenty of examples online.

A

Anonymous

Mar 09, 2026

Rating: 5/5

Exactly as described

Fast shipping and the product matches the description perfectly. Works great for counting revolutions on my 3D printer fan upgrade.

A

Anonymous

Mar 07, 2026

Rating: 5/5

Perfect for my RPM counter project

This module worked flawlessly with my Arduino Uno. I used it to measure the speed of a small DC motor, and the readings were consistent. The LED indicator is very helpful for debugging.

A

Anonymous

Mar 04, 2026

Rating: 5/5

Reliable and sensitive

I've tested several hall sensors, and this A3144 module is very responsive. It detects the magnet from a decent distance, which helps when mounting it inside a chassis.

5 FAQ

Q: Does this module work directly with 3.3V logic like the ESP32?

A: Yes, the module operates within a 3.3V to 5V range, making it fully compatible with 3.3V microcontrollers like the ESP32 and micro:bit without needing level shifters.

Q: Is a magnet included in the package?

A: No, the package includes only the Hall sensor module. You will need to provide your own magnet for testing or integration into your project.

Q: Can I use this to detect gear teeth on a metal wheel?

A: This specific module detects magnetic fields, not metal directly. To detect gear teeth, you would need to attach a small magnet to the rotating gear or use a ferrous metal detection setup with a magnet placed behind the sensor.

Q: What is the maximum current this sensor can switch?

A: The A3144 chip typically handles up to 25mA. For driving higher current loads like relays or bright LEDs, we recommend using a transistor or MOSFET between the module output and the load.

Q: How do I connect this to an Arduino?

A: Connect the VCC pin to 5V, GND to Ground, and the OUT pin to any digital input pin on your Arduino. You can then read the HIGH/LOW state in your code to detect the presence of a magnet.

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