Hall Effect Sensor Module
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 onboard LED indicator.
It's 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 (+), and connect the "-" pin to the ground. Supply voltage to the middle pin. The "S" pin will go low (gets pulled to the ground) and the onboard LED indicator will turn on when a magnet is brought near.
Pin Description:
VCC : 2.3 volts to 5.3 Volts
GND : power supply ground
AOUT (analog sensor output) : Arduino/ MCU input
DOUT (digital sensor output) : Arduino/MCU input
Applications:
Motor shaft speed measurement (shaft encoder)
Object position detection
Docking Detection
Door Open and Close Detection
Proximity Sensing
Valve Positioning
Pulse Counting