Hardware Overview

Welcome to the official VDriveMotion Hardware Wiki. This documentation provides comprehensive pinouts, electrical characteristics, wiring schematics, and configuration instructions for the VDriveMotion High-Performance Sensorless FOC (Field Oriented Control) Motor Controller.

The VDriveMotion controller is engineered for applications demanding high torque density, precision dynamics, and space-constrained integration, such as quadrupeds, robotic arms, aerospace actuators, and automated guided vehicles (AGVs).

Key Features

• Sensorless Operation: Tracks rotor position down to 0 RPM via magnetic saliency tracking.
• Integrated Measurement: 3-Phase low-side shunt resistor current sensing for high-accuracy FOC control.
• Compact Thermal Layout: Direct thermal-via coupling to an aluminum heat plate for optimal dissipation.
• Multiple Control Modes: Seamlessly transition between Torque, Velocity, and Position loops.
• Connectivity: Standard CAN-FD, high-speed UART, and I2C interfaces for robotic system bus configurations.

Electrical Specifications

Ensure that all operating variables remain within the absolute maximum bounds listed below. Exceeding these specifications can result in permanent damage to the onboard power stage (MOSFETs, gate drivers) and logic controllers.

TIM8-Synchronized Current Oversampling

The controller employs a specialized hardware-synchronized phase current oversampling system to minimize switching noise and maximize current loop control authority:

• Hardware Triggering: The auxiliary timer TIM8 is configured in OnePulse Mode (Slave Mode triggered by TIM1 TRGO via the internal ITR0 coupling). This ensures current measurements are started exactly at the center-point of the PWM cycle where switching transients are minimal.
• Dynamic Symmetrical Windowing: Based on the active duty cycles (CCR1, CCR2, CCR3), the firmware dynamically adjusts the oversampling window length. A Duff's Device implementation processes up to 17 samples symmetrically balanced around the PWM midpoint in a half-cycle.
• 16x Telemetry Resolution Scaling: Raw ADC current averages are multiplied and accumulated to scale values 16x larger. This preserves low-level sub-mA resolution inside the integer math pipeline.

Connectors & Pinouts

The controller exposes interfaces for power, phases, communication, and auxiliary peripherals. Below are the physical layouts and pin mappings for the primary ports.

1. Main Power & Motor Terminals

2. Control Port (10-Pin JST-GH)

This connector houses the primary communication protocols (CAN-FD, UART, I2C) used to interface with a master controller (such as a Raspberry Pi, Jetson Nano, or microcontroller board).

3. SWD Programming Port (4-Pin, 2.54mm Pitch)

Exposed on the bottom edge of the board for debug and low-level flashing of the STM32 microcontroller.

Wiring & Setup

Follow these wiring steps to configure the controller safely for initial power-on. Incorrect polarity or shorted phases can lead to immediate silicon failure.

Firmware Flashing

The controller runs a custom STM32-based FOC firmware. Firmware updates can be performed directly from your browser using the web tool, or via a hardware debugger using the Serial Wire Debug (SWD) port for recovery.

Web-Based Flashing via USB

Firmware updates are flashed over a standard USB-C connection using the built-in USB bootloader:

1. Connect the controller to your PC using a USB-C cable.
2. Power on the controller via the DC input.
3. Open Chrome or Edge and navigate to tool.vdrivemotion.com.
4. Click Connect and select the controller's USB COM port.
5. Once connected, click the Firmware Update button in the top menu or connection panel.
6. Select the firmware version you wish to flash (or upload a custom .bin file) and click Flash Firmware. Do not disconnect the power or USB cable during this process.

Advanced: SWD Flashing via ST-Link

For fresh boards or recovery flashing after a bricked bootloader, connect an ST-Link V2 or V3 debugger to the SWD port. Note: only connect GND, SWCLK, and SWDIO if the board is powered via the main battery terminals.

# Erase chip and program the ELF binary
openocd -f interface/stlink.cfg -f target/stm32g4x.cfg \
  -c "init" \
  -c "reset halt" \
  -c "flash write_image erase build/vdrivemotion_firmware.elf" \
  -c "verify_image build/vdrivemotion_firmware.elf" \
  -c "reset run" \
  -c "shutdown"

Advanced: Using STM32CubeProgrammer GUI

1. Connect the ST-Link programmer to your PC and the controller's SWD port.
2. Power on the controller via the DC input.
3. Open STM32CubeProgrammer. Set the interface mode to SWD and click Connect.
4. Go to the Erasing & Programming tab. Browse to select your firmware file (vdrivemotion_firmware.bin or .hex).
5. Check the Verify programming checkbox.
6. Click Start Programming. Once complete, click Disconnect and power-cycle the board.

Motor Calibration

Before driving a brushless motor under FOC, you must perform motor identification parameter detection. This configures the internal resistance (R), inductance (L), and flux linkage (λ) parameters inside the controller.

Step-by-Step Parameter Detection

1. Open your browser and navigate to tool.vdrivemotion.com (Chrome recommended for Web Serial).
2. Click Connect, select the controller's USB COM port, and verify that telemetry readings display in the side dashboard.
3. Navigate to the Motor Tuning menu and select the FOC Setup Wizard.
4. Enter the approximate current limits (e.g. 15A for estimation) and the number of pole pairs (typically 7 for a standard 14-pole gimbal or outrunner motor).
5. Click Run RL Detection. The motor will hum quietly for 3 seconds while measuring winding resistance and phase inductance.
6. Click Run Flux Linkage Detection. The motor will spin slowly in both directions to calculate the rotor's flux constant.
7. Review the measured parameters. Click Apply and Save Configuration to write these values to the non-volatile EEPROM memory.

Zero-Speed Saliency Tracking

The controller features fully automated zero-speed saliency tracking using High-Frequency Signal Injection (HFI):

• Active HFI Ripple Cancellation: Dampens phase current ripples in the alpha-beta domain, improving position estimation signal-to-noise ratio (SNR).
• Dual-Pulse Saliency PLL: Automatically tracks the magnetic saliency axis, which repeats twice per electrical cycle.
• Adaptive Observer Bandwidth: The Saliency PLL dynamically adjusts its loop bandwidth and damping to filter out mechanical noise under different speed and load configurations.
• Phase Lead Compensation: Compensates for filter group delays with a smooth, software-faded lead angle transition to eliminate zero-speed jitter.

Serial Command API

The controller exposes a standard ASCII text-based Serial/USB communication API. Commands can be sent via the USB-C virtual COM port or the primary JST-GH UART interface. Command packets use the format COMMAND:PARAM1,PARAM2,... followed by a newline (\n).