Description:-
Hall Effect Sensor Module is used to Detect the proximity of a magnet. It is very much Smaller in size. When the magnetic field rises above a threshold level, the open-collector output transistor switches on, which pulls the logic-compatible output low and illuminates the on board LED indicator.
Its fast (The turn-on threshold is 35-450 Gauss, the minimum hysteresis is 20 Gauss, and the operating voltage range is 4.5 - 24 volts.This module uses the Allegro MicroSystems A3144EUA sensor. It has a 3 pin interface, signal, V+ and GND.
To use this sensor/switch, place a 10K pull-up resistor between the "S" pin and the middle pin (+), connect the "-" pin to ground. Supply voltage to the middle pin. The "S" pin will go low (gets pulled to ground) and the on board LED indicator will turn on when a magnet is brought near.