A device controller system incorporates an inexpensive Hall element to detect motion of a brushless DC motor. A magnet, which is part of a motor rotor, passes by the Hall element producing a Hall voltage each rotation. The Hall voltage is coupled through an interface port to a comparator within a process controller. A microprocessor within the process controller calculates a control response based on a comparator output signal. The interface port is rapidly configured to provide signals produced from the control response as output to device drivers on the same input-output pins that receive the Hall voltage. The device drivers produce a current through fan coils producing an update in the magnetic field of each motor phase which updates the speed of the fan according to programming within the process controller. Rapid configuring and reconfiguring of the interface port allows all necessary components of the controller system to be used with a single rotational commutation cycle.