Reproducible Vision-Guided 6-DoF Robotic Manipulator with a Mixed Stepper-Driver Architecture and Browser-Native Control
2026-08-24 • Robotics
RoboticsComputer Vision and Pattern Recognition
AI summaryⓘ
The authors created the NeuralNexus Arm, a low-cost, six-joint robot arm designed by undergraduate students. It uses one microcontroller to control different types of motor drivers for precision and strength in various parts of the arm. They shared details on the mechanical build, electronics, software for movement calculation, and a web-based control system. They also explain problems they encountered when moving from prototype boards to custom hardware, offering guidance for others to reproduce their design. All designs and software are openly available for anyone to use.
6-DOF robotic manipulatorSTM32H743 microcontrollerstepper motor driversinverse kinematicsprinted circuit board (PCB)interrupt-driven firmwareWeb Serial APIMATLAB/Simscapepick-and-place automationmotor control
Authors
Lasan Perera, Deneth Priyadarshana, Dulana Pitiwaduge, Isitha Dinujaya, Mokshan Colambage
Abstract
We present the NeuralNexus Arm, an open, low-cost 6-DOF robotic manipulator built by an undergraduate engineering team, together with the design decisions and debugging experience needed to reproduce it. The arm is driven by a single STM32H743 microcontroller on a custom printed circuit board (PCB) and combines two stepper-driver strategies on one controller: push-pull 3.3 V step/direction outputs for onboard TMC2209 drivers on the three wrist joints, and open-drain outputs for external CL57T and DM542 drivers on the three high-torque proximal joints. We describe the mechanical design, mixed-driver electronics, interrupt-driven firmware, a MATLAB/Simscape-based inverse-kinematics pipeline, a browser-native control interface using the Web Serial API, and a lightweight vision pipeline for object localisation and autonomous pick-and-place tasks. We also document non-obvious hardware and firmware failure modes encountered during the transition from a development board to the custom PCB as reproducibility guidance. All design files and firmware are released openly. The platform actuates all six axes under coordinated control at a 2 kHz update rate and executes both manual and pre-recorded motions from the browser interface.