I am using the A1301KUA-T IC Hall effect Sensor. It operates at 5V dc and outputs 2.2 - 2.8 VDC as a Quiescent current.
I will be using the magnetic pole that drops that voltage to 0.1 or so volts. If the AVR is powered at 5V I assume this range of quiescent current will make that a problem since the Uc's pin input hysteresis is in that range.
Is using a 3.75 VDC input for the micro controller chip a good choice, that would make the 2.2 - 2.8 VDC range of the Hall sensor read HIGH.
Perhaps that output hysteresis assumes a 3V uC?
Basically the Uc is just being used as a Schmidt trigger and an led output of each sensor.