The Hall effect sensor outputs a digital HIGH or LOW depending on whether a magnetic field is present. The most common module uses the A3144 or SS49E IC and includes an indicator LED.
| Supply voltage | 3.3 – 5 V |
| Output type | Open-drain digital |
| Field sensitivity | ≥ 10 mT (typical) |
| Response time | < 1 µs |
| Operating temp | −40 to +125 °C |
| Package | TO-92 / 3-pin module |
A Lorentz force deflects charge carriers in a semiconductor when exposed to a perpendicular magnetic field, creating a measurable voltage difference. The integrated comparator converts this to a clean digital output.
Only detects magnetic fields — cannot measure field strength in digital mode. Trigger polarity matters: south-pole facing most sensors activates output. Omnipolar variants exist but are less common.