Protocol Of Motor - Waveshare HAT User Manual

Stepper Motor HAT User Manual

PROTOCOL OF MOTOR

According to Ampère's circuital law, when current of coil A flow from left to right,
stator generates magnetic field, internal side is North pole which will adopt rotator of
motor. When the currents of four coils based on certain rule, they will generate a
rotate magnetic field and drive the rotator rotate. If every motor has four rotators, it
has four statuses:
Status 1: coil A left in right out(current), coil C right in left out, motor rotate 0 degree;
Status 2: coil B top in bottom out, coil D bottom in top out, motor rotate 90 degree
against status 1.
Status 3: coil A right in left out, coil C left in right out, motor rotate 90 degree against
status 2;
Status 4: coil B bottom in top out, coil D top in left out, motor rotate 90 degree
against status 3;
Motor turn from previous status to next status, we call it step. Motor rotate in a circle
every four steps, and its step angle is 90 degree.
Most of motors have more than four stators. For example, 42 motor, 57 motors all
have 50 stators with step angle 1.8 degree.
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