Patent ID: 8242732

Claim:
An apparatus comprising: a conversion module that receives an electrical waveform produced in a non-driven coil of a stepper motor by a magnetic field of a rotor of the stepper motor during a full step operation, and samples the electrical waveform at intervals starting at a predetermined time for a predetermined period of time within the full step operation to yield a plurality of sampled data points; a rectification module that rectifies the electrical waveform about a predetermined quiescent level; and a comparison module that accumulates the sampled data points into a statistically representative sampled value, compares the representative sampled value to a predetermined threshold level, and indicates a stall of the rotor if the representative sampled value is less than the predetermined threshold level, wherein the conversion module, the rectification module, and the comparison module comprise one or more of logic hardware and executable code, the executable code stored on one or more computer-readable media.