HsMouse Quad A4988 Motor Controller HAT

Warning: This project is not intended for production use. It is a learning exercise for KiCad and PCB design fundamentals.

Overview

This Raspberry Pi 5 HAT features four A4988 stepper motor driver chips, designed to control four NEMA stepper motors. The primary application is a small robotic car using Mecanum wheels for omnidirectional movement.

Features

• Motor Control: Four A4988SETT-R drivers for independent control of NEMA stepper motors.
  • Shared GPIO connections for common pins (e.g., MSx, ROSC, ~ENABLE) to simplify control logic.
  • Assumes synchronized wheel speeds when enabled.
• Precision Voltage Reference: ISL21080 provides a stable 0.9V reference to all A4988 VREF pins, limiting motor coil current to 1.125A.
• Directional Logic: SN74LVC2G08DCUR dual AND gate enables diagonal wheel movement by selectively disabling STEP signals (see movement table below).