Description
Reviews
| Brand | - |
| Category | Robotics / STEM Teaching Tools / Sensors |
| Origin | - |
| Model Number | KY-003 |
| Sensor Type | A3144E Unipolar Hall Effect |
| Operating Voltage | 4.5V to 24V DC |
| Output Signal | Digital Switch (Low when magnetic field detected) |
| Pin Configuration | 3-Pin (GND, VCC, Signal) |
| PCB Dimensions | 18mm x 13mm x 3mm |
| Mounting Hole Diameter | 3mm |
| Response Time | < 4 microseconds |
| Operating Temperature | -40°C to +85°C |
| Compatibility | Arduino, Raspberry Pi, ESP32, STM32 |
Anonymous
Mar 31, 2026
Rating: 5/5
Great for beginners
Plug and play with most microcontroller boards. The built-in pull-up resistor saves time on prototyping. Excellent quality for the price point.
Anonymous
Mar 21, 2026
Rating: 5/5
Perfect for RPM counting projects
I used this module to build a tachometer for my 3D printer fan. The response is instant and the output is clean. Very easy to interface with an Arduino Uno.
Anonymous
Mar 16, 2026
Rating: 5/5
Essential component for robotics
Bought five of these for a line-following robot project using magnetic tape. They are consistent and robust. Highly recommended for students and makers.
Anonymous
Mar 16, 2026
Rating: 4/5
Solid performance
Works well within the specified voltage range. I tested it at 5V and 12V with no issues. Just remember it's unipolar, so it only reacts to one pole of the magnet.
Anonymous
Mar 11, 2026
Rating: 5/5
Reliable and compact
Small footprint makes it easy to fit into tight enclosures. I'm using it as a door open/close detector for a smart home project. No false triggers so far.
Anonymous
Mar 03, 2026
Rating: 4/5
Good value, works as expected
The sensor triggers reliably with a standard neodymium magnet. The only minor issue is that the silk screen on the PCB is slightly faint, but the pinout is standard so it wasn't a big problem.
Q: Does this module work with 3.3V logic levels like the ESP32?
A: Yes, the module operates between 4.5V and 24V for power, but the digital output is compatible with 3.3V logic systems. Many users successfully connect it directly to ESP32 GPIO pins.
Q: Which magnetic pole triggers the sensor?
A: The A3144E is a unipolar switch. Typically, the South pole of a magnet facing the front of the sensor (the side with the chip) will trigger the output to go Low. Please test with your specific magnet orientation.
Q: What is the maximum current this sensor can switch?
A: This module is designed for signal processing, not high-power switching. The output current is limited (typically around 25mA). You should use a transistor or relay to drive higher loads like motors or bright lamps.
Q: Can I use this underwater?
A: The PCB itself is not waterproof or conformal coated. If you need to use it in wet environments, you must enclose the entire module in a waterproof housing while ensuring the magnet can still affect the sensor through the casing.
Q: Is there a built-in LED indicator on the board?
A: Yes, there is a small SMD LED on the module that lights up when the magnetic field is detected and the output switches to Low, providing visual feedback.
Rubber Speed Bump End Cap Heavy-Duty 1 Pack
$72.46
Front Wiper Arm Assembly for Citroën C-Elysée, Xsara Picasso, Peugeot 307/301
$35.00
Underbite Corrector Case - Portable Magnetic Lanyard Storage Box for Frankel Appliance and TB Palatal Expander
$22.70
Car Tire Stone Removal Tool, Multi-Function Hook for Picking and Extracting Stones from Treads
$6.43
Outdoor Lamp Stand for Camping, Lantern Holder Pole for Street Vending and Night Fishing
$13.89
Waste Removal and Paper Stacking Machine, Automatic Paper Collection and Counting Receiver for Carton Printing Equipment, Carton Factory Machinery
$6,400.00
Sheepskin Baby Rattle - Chewable Traditional Handmade Shaker Bell, Intangible Cultural Heritage Essential for Newborn Care
$57.00
Zhizhi Study Room 'Small Pot Sky' Brush Washer - Traditional Handmade Glass with Lost-Wax Method, Silk Luster, Double-Compartment Water Vessel
$457.00
Zao Boshi Insulated Food Cart - Programmable Banquet Warmer for Buns, Breakfast Items, and Hotel Dry/Wet Dishes
$11,566.00
![Lichuan JK [Blood Oath] - Original Authentic Japanese Dark Style Embroidered Sailor Suit - Spring/Autumn Set](https://www.gosteppe.com/cache/small/product/269363/legacy-main-0b86f0b7795c15ee2c8be0d3.webp)
Lichuan JK [Blood Oath] - Original Authentic Japanese Dark Style Embroidered Sailor Suit - Spring/Autumn Set
$59.00
Sink Storage Rack Stainless Steel No-Drill Kitchen Sponge Steel Wool Cloth Pot Lid Organizer Wall-Mounted Drain Rack
$4.93
Sketch Blending Stump Set for Artists - Detail Highlight and Shadow Smudging Tools with Replacement Tips
$14.80
Softening Agent for Board Arcs Melamine Softener Eco-Friendly Board Paint-Free Board Whole House Customization Arc Softener
$9.30
Car Tire Stone Removal Tool - Hook Picker for Cleaning Pebbles from Vehicle Treads
$3.90
Electrical Box with PLC System and VFD for Fans and Pumps
$2,519.00
Zunjue Watercolor Sketchbook 300g Fabric-Covered Journal – Portable Acrylic Marker Book, 100% Cotton Flip-Style Concertina Drawing Paper
$13.70
French Imported Arches Watercolor Paper, Handmade Cotton Pulp 300g Full/Half/4K/8K/16K/32K Rough/Medium/Fine Grain, 185g Cotton Pulp for Postcards and Watercolor Books
$20.80
![[Official Authentic] Zichao Bear Wanda Cinema Popcorn Acrylic Keychain Plush Doll Cute Toy](https://www.gosteppe.com/cache/small/product/269355/legacy-main-ae40bf0d9a6007e2f30a9130.webp)
[Official Authentic] Zichao Bear Wanda Cinema Popcorn Acrylic Keychain Plush Doll Cute Toy
$25.40
Heidelberg Printing Press Automatic Blanket Wash Cloth - Non-Woven Cleaning Fabric, 500m Roll
$3,185.00
Bucket Pack Natural Wood Colored Pencils Water-Soluble for Kids Coloring and Doodling
$6.65
Chunfei Grocery Store Yunm'an GR02 Gravel Bike - Thru-Axle Disc Brake, Lightweight Touring with Multiple Rack Mounts
$6,444.00
Variable Frequency Drive Power Board ZPOW-591 for ACS880
$2,200.00
Professional Sketching Eraser Kit - Blending Stumps, Sponges, and Paper Tortillons for Highlight & Shadow Correction
$3.90
Weighted Water Bag with Handle, Thickened PV Mesh Gravity Ballast for Banner Stand Fixation (8KG)
$35.10
Ultra-Fine Purification Lint-Free Cloth Cleaning Cloth Lens Wipe High Quality 0730 Water-Absorbing Dust Removal UV Nozzle 100 Sheets
$96.00
Wen Zhengming Small Regular Script Calligraphy Cards: Li Sao Jing, Thousand Character Classic, Qin Fu, Cao Tang Shi Zhi, Qing Jing Jing, Record of the Drunken Pavilion, Red Cliff Ode
$59.00
Zhizhi Manshu Zhao Mengfu Small Regular Script Collection of Ancient Classics (Vol. 1) - Calligraphy Copybook, Brush Writing Cards, Foldable Practice Cards
$49.00
Language of Drums Motion Path Set - Essential Creativity and Rhythm Teaching Material for Drum Kits and Jazz Drums
$59.14
onlycook Sink Drain Basket, Faucet-Mounted Food Residue Separator and Washing Strainer - 1 Pack
$14.10
Heavy-Duty Wiper Arms and Blades for Trucks and Agricultural Vehicles - Universal Replacement Wiper Rubber Strips
$5.50
![[Youxin Electronics] GP2Y0E03 Infrared Distance Sensor Module 4-50cm Range](https://www.gosteppe.com/cache/medium/product/74667/legacy-main-4da8cadc5fc82afe91b124e3.webp)
![[Trial Pack] Xianlang Complete Cat Treat Sticks Meal Packs Main Course Cans Freeze-Dried Cat Food Sample Snacks Gift Set](https://www.gosteppe.com/cache/medium/product/208273/legacy-main-9ec245ebf781f65a434ba854.webp)
