Jaycar DuiNotech Arduino-Compatible Hall Effect Sensor – 4.5–28VDC, Schmitt-Trigger Output

You need to detect a magnet passing a fixed point – a door switch, a rotation counter, a proximity trigger – and you don't want a reed relay clicking behind your project. This DuiNotech Hall effect sensor gives you a clean digital read: output goes high at 30 Gauss (3 mT) and drops at 10 Gauss (1 mT). The built-in Schmitt trigger means you get a crisp, noise-free signal straight into an Arduino digital pin, no external pull-up gymnastics. Runs anywhere from 4.5 to 28 VDC, so it slots into your 5V logic board or a 12V motor controller without a level shifter. At 20 × 15 × 3 mm it bolts or clips behind a panel where the magnet sits. Solder three wires, mount it, and your position sensing is done

• Switches on at 30 Gauss (3 mT), off at 10 Gauss (1 mT) – predictable threshold for repeatable triggers
• Schmitt-Trigger output for clean, debounced digital signal into any microcontroller pin
• Operating voltage 4.5–28 VDC – no level shifter needed between 5V logic and 12V/24V systems
• Compact 20(W) × 15(L) × 3(H) mm package for tight panel or enclosure mounting
• Arduino-compatible 3-pin interface