About this manual¶

Scope and audience¶

The STEPFOC Manual covers the STEPFOC stepper driver from unpacking to a tuned motor on a CAN bus: what the driver is, how to mount it on a motor and wire it, the first setup over the serial terminal, calibration and tuning, how the driver is controlled over UART and CAN or from Python, and how its firmware is updated. The Reference lists every CAN message and UART command of the firmware release named on the landing page. The Guides are worked examples.

It is written for someone who builds a robot or a machine with STEPFOC: a maker, a student or an engineer who can solder four motor wires and open a serial terminal. It does not assume any knowledge of field-oriented control; the Theory corner in the appendix explains the concepts the control modes rely on.

Read the Safety chapter before you power anything. The Quick start is the whole first setup on one page; the chapters are in the order you need them and go deeper.

Finding your way¶

The header has four tabs. STEPFOC Manual is the document you read from the start: the quick start, then safety, technical data, mounting, the first setup, operation and firmware updates, in numbered chapters. Motor GUI, the tool in the browser, is the usual way to do what the chapters describe; each procedure shows it first and the terminal command beside it. API reference lists every CAN message, every UART command and the Python library's calls for the firmware release this site describes, with the defaults and the error flags, and is where you look things up. Guides are worked examples with code. Support says where to get help and how to report a problem.

The whole site describes one firmware release. The dropdown next to the site name switches between releases, and a page from an older release says so in a bar at the top. The repository card on the right of the header opens the firmware repository; every page ends with a link to edit it and one to report a problem with it.

Warnings and notes¶

Three kinds of highlighted text appear in this documentation. Read every Danger and Notice before you act on the step it belongs to.

Note

Points out something that is easy to miss or that changes what follows: a default, a limit, a side effect.

Notice

The driver, the motor, the machine or data can be damaged or lost if this is ignored. Nobody is at risk.

Danger

Someone can be injured if this is ignored. Stop and read the whole box before acting on the step it belongs to.

Document	Number	Covers
STEPFOC Manual	SR-5001	the STEPFOC stepper driver: quick start, safety, technical data, mounting, setup with Motor GUI or a terminal, operation, firmware; the API reference; guides

A document marked with a firmware version describes that firmware release, here 108; the version selector in the header switches between releases. The compatibility table says which firmware, Python library and hardware revisions work together.

The Spectral Micro BLDC driver has similar hardware and firmware and is run the same way; its documentation is at docs.source-robotics.com/Spectral-BLDC-docs. The grippers driven by STEPFOC electronics are documented at docs.source-robotics.com/MSG-gripper-docs.

Document history¶

The STEPFOC Manual describes one firmware release; one revision is kept per release, and the version selector in the header switches between them. The earlier version of this site, for firmware 103, is kept as version 103.

The text and the images of this documentation are licensed under CC BY-SA 4.0, the code examples under the MIT licence. The Source Robotics name, the product names and the logos are not covered by either.

Revision	Date	Changes
2026.A	2026-11-03	First version in this form: the manual chapters, the generated CAN and UART reference, firmware 108

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