| 摘要 |
A method of detecting a stall condition in a stepper motor with very little movement of an instrument pointer coupled to the stepper motor. The stepper motor rotates the instrument pointer in a first direction towards a pointer stop by a plurality of micro-steps. The stepper motor then rotates the pointer in the first direction at least one additional micro-step while monitoring a back electro-motive force (EMF) produced by the stepper motor. If the instrument pointer is abutting the pointer stop, then the stepper motor will be compressed slightly. If the back EMF is below a predetermined threshold, then the stepper motor is in a stall condition. The instrument pointer can then be micro-stepped in a second direction opposite the first direction to a micro-rotor offset value (μROV) position. |
