Motor Driver Guide

Our robot uses the XDrive MINI motor driver board from Makerbase (MKS) in place of the motor controller used by the original Berkeley Humanoid Lite. The XDrive MINI is based on ODrive v3.6 and has an on-board AS5047P encoder.

XDrive MINI motor driver board, with green screw terminal blocks for motor phases A, B, C and DC power, five capacitors, and connectors along the bottom edge.

XDrive MINI (image: Makerbase)

XDrive MINI product page (Makerbase)

Changing the driver board also changed some actuator parts. See What’s different from Berkeley Humanoid Lite on the actuator assembly page.

Official documentation and resources

ODrive documentation (v0.5.6): Getting Started: the official ODrive documentation for the ODrive v3.6 generation, which the XDrive MINI is based on.
MKS ODrive video playlist (YouTube): Makerbase’s official tutorial videos for their ODrive-based boards, covering the important setup steps.
MKS ODrive GitHub repository: Makerbase’s repository with the original firmware. The XDrive MINI firmware is in the Firmware/MKS ODrive_S folder.

Community project: MKS-XDRIVE-MINI

A community member has made a guide project for the XDrive MINI, with configuration instructions using the ODrive tool, firmware files, and troubleshooting tips, for example for running several drivers on one CAN bus. It’s a great place to start trying out and playing with the motor driver.

We recommend using this project to get comfortable with the motor driver before building the full robot. Practice:

using odrivetool

flashing firmware

setting up the motor driver configuration

running CAN communication

Course firmware (recommended)

For the project, we recommend using our modified firmware for the XDrive MINI:

xdrive-mini-fw-instant-start (GitHub)

It is a modified version of the MKS ODrive v0.5.1 firmware. The XDrive MINI’s on-board AS5047P is an absolute encoder, but the stock firmware still runs the encoder offset calibration again at every power-on. We modified the firmware so that the driver:

skips the encoder offset calibration at power-on, after a one-time calibration
starts from any rotor position and goes straight into closed-loop control, without jumping

To use it:

Download the .hex or .elf file from the repository’s Releases page.
Flash it to the XDrive MINI (see Flashing firmware below).
Configure the driver with the ODrive tool using xdrive_config.txt from the repository, which includes the one-time calibration.

See the repository’s README for the details of what was changed and how to configure the driver.

Flashing firmware

If your firmware is a .bin, .hex, or .elf file, we recommend STM32CubeProgrammer from STMicroelectronics to flash it quickly. To flash the firmware, you’ll need an ST-Link V2 programmer, connected to the driver board’s SWD pins.

STM32CubeProgrammer (STMicroelectronics)