Matthew Rief

Three-Axis Stepper Motor Driver Board

  • Role: Built at work (details kept general)
  • Key parts: STM32G491, stepper driver ICs, quadrature encoder inputs, RS-232
Stepper driver board, connector side, showing three axes of stepper, encoder, and reference switch headers Stepper driver board, component side, showing the STM32G491 microcontroller and supporting circuitry

Overview

A three-axis stepper motor driver board built as a direct implementation of a widely-used motor driver application note. It's designed to control three independent stepper axes with closed-loop feedback, rather than running them open-loop.

Design

Each axis provides quadrature encoder feedback, reference/limit switch inputs, and closed-loop step/direction control, all coordinated by an STM32G491 microcontroller. RS-232 and analog inputs bring in external sensor and communication data, and a dedicated power stage with bulk electrolytic capacitance handles 24 V motor transients across all three axes.

Challenges & What I'd Do Differently