Development of Custom Multi-Axis Stepper Controller with DRO Display and Numeric/Rotary Control Interface

Overview I need a fully custom motion control system for a stacked 3-axis setup (Z on X on Y) driven by closed-loop NEMA 11 stepper motors. The interface must be minimalistic and intuitive, always showing the DRO for all axes and supporting two operating modes: - Step Mode: relative moves with adjustable step size (via numeric input or rotary encoder adjustment) - Goto Mode: absolute moves to a specified coordinate The freelancer will design the workflow and UI, propose hardware (numpad, encoder, screen, etc.), and get my approval before implementation. The interface must remain simple — numeric keypad + rotary encoder, clear DRO display, no complex menus. Freelancer may use existing CNC controllers/modules if appropriate and cost-effective, as long as the interface is minimal and matches the requirements. Hardware Setup - Motors: Closed-loop NEMA 11 stepper, model 28EB34-0802 Link: [login to view URL] - Limit Switches: M6-thread DC type NPN NC Proximity Sensor Link: [login to view URL] - Encoders: The system shall support absolute encoders such as the Senyd SA2000. The freelancer shall define the specific model or requirements (resolution, protocol, connector, etc.). Axis Arrangement: - Y axis: vertical (up/down), dual rails with two motors driven in sync - X axis: horizontal (left/right), mounted on Y - Z axis: horizontal (forward/backward), mounted on X Travel Range: configurable in firmware, from 20 mm to 700 mm Accuracy Requirements: - Current: 0.1 mm - Future: ideally a few microns (freelancer must advise feasibility and limits based on chosen hardware) User Interface Input Devices: - 4×4 numeric keypad (0–9, +/−, ., Enter, Esc) - Rotary encoder with push button for navigation and step size adjustment Display: - Shows DRO for all three axes at all times - Step Mode: user selects axis; DRO shows all axes; active axis indicated; step size adjustable via numpad; step execution by rotary encoder or +/− keys - Goto Mode: absolute move; input temporarily replaces DRO for the selected axis until confirmed or cancelled Functions: 1. Init: only if using rotary encoders (homing to stop, then apply firmware-defined offset) 2. Set Zero: selectable option in UI 3. Step Mode: relative moves with user-adjustable increments 4. Goto Mode: absolute move to coordinate 5. Soft Limits: mandatory in all cases The freelancer shall propose the detailed UI workflow for approval. Development Guidelines - Controller: STM32 Blue Pill preferred (available on hand), otherwise Arduino-compatible MCU - Integration: PCB preferred (JLCPCB-ready Gerbers + BOM); otherwise, clean wiring harness acceptable. If connectors are needed, decent ones shall be chosen (e.g., D-sub or Nicomatic style). - Firmware: modular, with parameters (step angle, pitch, travel, step sizes) defined at the top of the code - Encoders: freelancer must recommend and define a specific absolute encoder model (Senyd SA2000 or equivalent), including connector type and communication protocol Deliverables Stage 1 (within 2 days of project start): - Hardware selection (must define keypad type: USB, serial, or other; rotary encoder switch; screen; step-up modules; connectors; etc. with product links) Final Deliverables: 1. Complete schematic and wiring diagram, or PCB design with BOM 2. Firmware source code (Arduino IDE / STM32 toolchain), well-commented and modular 3. UI workflow proposal (to be approved before coding) 4. Hardware list with product links (worldwide shipping, e.g., AliExpress; excluding Amazon) 5. Assembly and calibration instructions 6. Demo video of working system 7. Support for burning firmware to controller and initial setup Timeline - Hardware/module selection: within 2 days - Complete, tested system: within 2 weeks total Evaluation Criteria - Clarity and simplicity of UI design - Accuracy and load capacity achievable with chosen solution - Encoder selection (e.g., Senyd SA2000 or equivalent) and justification - Clean hardware integration (PCB or harness with D-sub/Nicomatic connectors) - Clear deliverables and documentation

Project ID: 39737086