A3144 Hall Effect Sensor Module

The A3144 Hall Effect Sensor Magnet Detector Switch for Arduino is a switch that will turn on/off in the presence of a magnetic field. If no magnetic field is present, the signal line of the sensor is HIGH (3.5 V). If a magnetic field is presented to the sensor, the signal line goes LOW, at the same time the LED on the sensor lights up.?An onboard LED will also indicate the presence of a magnetic field.