ESP32-S3 Based Closed-Loop Smart CAN Bus Stepper Motor Driver Board (v1.2)
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Overview • Development Status • Hardware Specs • PCB Preview • Schematic & CAD • Firmware & SDK • Official Hardware & Services • License
CANBUS-Stepper is a high-performance smart stepper motor driver board powered by the ESP32-S3 dual-core microcontroller. Designed specifically for 3D printer toolheads, robotic actuators, AGVs, CNC axes, and industrial automation, this board integrates:
- Ultra-Quiet Motor Drive: Trinamic TMC2209-LA driver with StealthChop2™, SpreadCycle™, and StallGuard4™ sensorless homing.
- Closed-Loop Position Feedback: High-precision AS5600 12-bit magnetic rotary encoder mounted coaxially on the bottom layer to eliminate missed steps.
- Native CAN Bus Communication: Automotive-grade TI TCAN3413 transceiver supporting high-speed CAN and CAN FD logic with 3.3V logic.
- Industrial Wide-Input Power: High-efficiency TI LMR33630 36V / 3A synchronous step-down DC-DC buck regulator + ultra-low-noise 3.3V LDO.
- Multi-Stage Protection Circuits: Reverse polarity P-MOSFET, transient voltage suppressors (TVS), ESD diode arrays, and resettable PPTC fuses.
- Compact NEMA 17 Footprint: Fits directly onto the rear face of standard 42mm x 42mm NEMA 17 stepper motors (40.3mm x 40.3mm profile with corner chamfers and M3 mounting holes).
| Component | Status | Details |
|---|---|---|
| Schematic Design | ✅ Complete | Hierarchical schematic design, PDF export available |
| PCB Layout (v1.2) | ✅ Complete | 2-Layer 1.6mm FR4, DRC clean, planar ESP32-S3 pin routing |
| Component Mapping (BOM) | ✅ Complete | 43 unique lines / 67 components 100% mapped with LCSC part numbers |
| 3D CAD STEP Models | ✅ Complete | Exported 3D assembly (step/canbus-stepper-v1.2.step) ready for enclosure design |
| Physical Prototyping | 🔄 In Progress | Prototype PCBA fabrication & physical hardware bring-up |
| Firmware & Control SDK | 🔄 In Progress | ESP32-S3 TWAI CAN driver, closed-loop PID loop & Klipper node support |
- MCU: ESP32-S3-MINI-1-N4R2 (Dual-core Xtensa® 32-bit LX7 @ 240 MHz, 2.4 GHz Wi-Fi 4 + Bluetooth 5 LE, 4 MB Flash, 2 MB Quad SPI PSRAM).
- USB Interface: Native Full-Speed USB 2.0 via Type-C connector with hardware CDC serial console & JTAG debugging support.
- Stepper Driver: Trinamic TMC2209-LA (VQFN-28 package with thermal vias).
- Operating Voltage: Up to 28V DC (recommended 12V – 24V).
- Current Capability: 2.0A RMS (2.8A Peak) motor phase current.
- Features: StealthChop2™ (silent operation), SpreadCycle™ (high dynamic torque), StallGuard4™ (load measurement & sensorless homing), CoolStep™ (energy saving).
- Interface: UART control for dynamic microstepping configuration (up to 256 microsteps) and real-time current scaling.
- Position Sensor: AMS AS5600-ASOT 12-Bit On-Axis Magnetic Rotary Encoder.
- Position Resolution: 4096 steps/rev (0.087° resolution).
- Mounting: Centered directly on PCB bottom layer for coaxial alignment with motor shaft diametral magnet.
- Interface: Fast-mode I2C (400 kHz).
- CAN Bus Transceiver: TI TCAN3413DRBR 3.3V CAN FD Transceiver with 3.3V V_IO logic interface and ±58V bus fault protection.
- Main DC-DC Buck Converter: TI LMR33630CRNXR Synchronous Step-Down Regulator (3.8V – 36V input range, 3.0A continuous output @ 2.1 MHz switching frequency) with Changjiang FNR4020S4R7MT (4.7µH / 2A) shielded power inductor and 0603 22µF output filter capacitor.
- MCU & Analog LDO: TI TLV75533PDRVR 500mA ultra-low-dropout 3.3V regulator providing clean power to ESP32-S3 and sensors.
- Bulk Filtering: 100µF / 50V Low-ESR aluminum electrolytic bulk capacitor (6.3mm x 5.8mm SMD) for motor switching current ripple suppression.
- Reverse Polarity Protection: HSBB6115 (-60V / -26A, 20mΩ R_DS(on) P-Channel MOSFET) with 12V Zener gate clamping (BZT52C12S SOD-323).
- Overcurrent Protection:
- 1.5A / 24V Resettable PPTC fuse (
1210L150/24WR) on main 24V DC input rail. - 500mA / 6V Resettable PPTC fuse (
JK-SMD0603-050/6V0603) on USB VBUS power line.
- 1.5A / 24V Resettable PPTC fuse (
- Transient & ESD Protection:
- PESD1CAN TVS diode array on CAN Bus differential lines (CAN_H / CAN_L).
- SMF26CA 26V / 200W Bidirectional Transient Voltage Suppressor (SOD-123FL) on main 24V DC input.
- STMicroelectronics USBLC6-2P6 ultra-low capacitance ESD protection array on USB D+/D- lines.
- MBR0520 Schottky diode for safe USB/Main power OR-ing.
| Connector / Component | Type / Footprint | Function |
|---|---|---|
| USB-C | 16-Pin USB Type-C Receptacle | Firmware flashing, USB CDC serial debugging & power |
| 24V Power In / Out | 2x Molex Micro-Fit 3.0 (436500209) 2-Pin | 24V Main power input & daisy-chain pass-through |
| Motor Output | JST PH 4-Pin SMD (S4B-PH-SM4-K-TB) | 4-wire bipolar stepper motor phases (A1, A2, B1, B2) |
| Qwiic / I2C Port | JST SH 4-Pin (1.0mm) Horizontal | External I2C sensors, OLED displays & expansions (3.3V, GND, SDA, SCL) |
| AUX Port | JST SH 4-Pin (1.0mm) Horizontal | Auxiliary GPIOs for endstops, bed probes, or toolhead sensors |
| CAN Bus In / Out | 2x JST SH 2-Pin (SM02B-SRSS-TB) | CAN Bus differential input & daisy-chain pass-through (CAN_H, CAN_L) |
| OLED Display FPC | Amphenol SFV30R-2STBE1HLF (30-Pin 0.5mm) | Bare COG OLED display panel interface (SSD1306) |
| CAN Termination | SMD Slide Switch (MSK12C01G15-W) |
Switchable 120Ω CAN bus termination resistor |
| Buttons & Indicators | 2x Tactile Push-Buttons + 3x LEDs | RESET, BOOT/User buttons; Power, Driver, and CAN Status LEDs |
Figure 1: CANBUS-Stepper v1.2 Component Layout — Top Layer (Left) & Bottom Layer (Right)
To enable seamless third-party software integration, driver development, and custom enclosure modeling, official hardware reference documents are provided:
- Schematic Circuit Diagrams (PDF):
- Complete multi-sheet reference schematics are available in
docs/schematics/CANBUS_Stepper_v1.2_Schematic.pdf(Legacy v1.1 & v1.0 available indocs/schematics/). - Details MCU pinouts, TMC2209 UART buses, CAN transceiver wiring, protection circuits, and sensor connectors.
- Complete multi-sheet reference schematics are available in
- 3D Mechanical STEP Assembly:
- Ready-to-import 3D CAD model:
step/canbus-stepper-v1.2.step. - Accurate component heights, connector positions, and NEMA 17 rear mounting hole spacing (31.0mm x 31.0mm diagonal M3 holes).
- Ready-to-import 3D CAD model:
CANBUS-Stepper/
├── README.md # Main project documentation & specifications
├── LICENSE # CC BY-NC-SA 4.0 (Hardware Reference) & MIT (Software)
├── .gitignore # Git ignore rules
├── docs/
│ ├── assets/ # 3D PCB renders, board photos, and diagrams
│ └── schematics/ # Full PDF Schematic & Pinout reference documentation
│ ├── README.md # Sheet breakdown and integration guide
│ └── CANBUS_Stepper_v1.2_Schematic.pdf
├── firmware/ # ESP32-S3 Firmware, Protocol & SDK
│ ├── include/ # Drivers, control loops, and headers
│ ├── src/ # Motion controller, TWAI CAN, AS5600, TMC2209
│ ├── klipper/ # Klipper toolhead configuration & docs
│ ├── platformio.ini # PlatformIO build configuration
│ └── README.md # Firmware architecture & roadmap
└── step/ # 3D CAD STEP Files for mechanical integration
├── canbus-stepper-v1.2.step # Full 3D PCB assembly STEP model (v1.2)
└── README.md # Mounting specifications & CAD guide
The ESP32-S3 microcontroller firmware is developed under firmware/ and targets both standalone robotic motion control and 3D printing ecosystems:
- TWAI CAN Protocol: High-speed command parser for position target streaming, velocity profiling, and status telemetry.
- Closed-Loop PID Loop: High-frequency reading from the AS5600 magnetic encoder with real-time step error correction and missed step prevention.
- Klipper CAN Toolhead Support: Compatibility with Klipper firmware for plug-and-play toolhead CAN node integration.
- ROS2 & Micro-ROS: Direct actuator node integration for robotic arms, wheeled rovers, and multi-axis mechanisms.
- Open SDK: Python and C++ driver libraries for controlling motors over USB-to-CAN adapters.
Ensure guaranteed hardware quality and support ongoing development through Official Pre-Assembled Hardware & Engineering Services:
- 🛠️ Factory-Tested Boards: 100% SMT assembled, flashed with factory test firmware, and validated under motor load.
- 🧲 Complete Motor Kits: Bundled with high-temperature NEMA 17 stepper motors, matched diametrically magnetized shaft magnets, 3D printed mounting brackets, and pre-crimped Molex/JST wire harnesses.
- ☕ Support Ongoing Development: Official hardware sales directly fund continuous firmware development, Klipper modules, and future hardware revisions.
Need customized hardware or industrial integration for your commercial robotics or automation project?
- Custom PCB Redesigns (Multi-axis drivers, 48V high-voltage input, RS485 / EtherCAT / DroneCAN).
- Industrial Firmware & ROS2 / Micro-ROS Drivers.
- Volume Batch Manufacturing & PCBA Sourcing.
👉 For pre-orders, volume batch requests, or custom engineering consulting, please reach out via GitHub Issues or contact the maintainer.
This project follows a Hybrid Open-Software & Reference-Hardware model:
- 🛡️ Hardware Reference (Schematics, Pinouts, Mechanical Specs & 3D STEP): Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0).
- 💻 Firmware & Software Stack: MIT License.
- 🏷️ Trademarks & Official Branding: The "CANBUS-Stepper" and "ILTERAY" names and logos represent official tested hardware.
CANBUS-Stepper • Open-Source Smart Motion Control