A “Hall-Effect Sensor” or simply Hall Sensor is a device to measure the magnitude of a magnetic field. Its output voltage is directly proportional to the magnetic field strength through it. When a Hall Sensor is combined with threshold detection, so that is acts as a switch. The 3144E based Hall Effect Sensor have both of those features. You can use it for motor speed, position detection etc…

The A0 pin gives the analog output which may change with the magnitude of a magnetic field. The D0 pin gives the digital output with build-in threshold detection circuity.

When the sensor comes in the range of the magnetic field, the digital output goes to LOW and the indication LED is turn ON. If there is no induction to the magnetic field, the digital output goes to HIGH and the LED is turn OFF.

The whole circuity and interface is fully compatible with any micro-controller based project.