Stepper-motor interface operating modes: A practical stepper-motor interface typically supports one of ________ operating modes (for example, wave drive, full-step, half-step, or microstepping).

Introduction / Context:
Stepper motors can be driven in several distinct modes, each trading torque, smoothness, and resolution. A well-designed interface or controller often allows selecting a mode that best suits the application, from simple coarse steps to fine, smooth motion.

Given Data / Assumptions:

• Common modes: wave drive, full-step, half-step, and microstepping.
• Controller exposes configuration pins or registers to select the mode.
• Power stage and current control are compatible with the chosen mode.

Concept / Approach:
Wave drive energizes one phase at a time (lower torque). Full-step energizes two phases for higher torque. Half-step alternates between one and two phases to double position resolution. Microstepping modulates currents sinusoidally for very fine resolution and smoother motion. Summarizing these gives four canonical modes.

Step-by-Step Solution:

Verification / Alternative check:
Commercial drivers (e.g., popular stepper ICs) document these modes and their selection tables, reinforcing the four-mode taxonomy.

Why Other Options Are Wrong:

Common Pitfalls:
Assuming microstepping is a single fixed resolution; in practice, microstep resolution can be selectable (e.g., 1/4, 1/8, 1/16).

Final Answer:
four