smartknob

SmartKnob

Coming soon...

Hardware

Designs

SmartKnob View

Premium SmartKnob experience. Under active development.

SmartKnob Handheld

An exploration of a small handheld form-factor. Under active development.

SmartKnob Mini

Planned for the future.

Component Info

Magnetic encoders

TLV493 (Infineon)

A decent choice, and easy to prototype with using Adafruit's QWIIC breakout board.

In my testing, it is a little noisy, requiring filtering/smoothing that can slow responsiveness, hurting control loop stability. Or, with less filtering, the noise can easily be "amplified" by the derivative component in the PID motor torque controller, causing audible (and tactile) humming/buzzing.

As of 2022-02-08, there is limited availability of this IC.

Datasheet

MT6701 (MagnTek)

Very promising based on the datasheet and initial prototyping.

• Haven't testing in a full control loop yet, but data looks good and relatively noise-free.
• Lots of IO options - SPI, I2C, and ABZ - should offer good response latency.
• No power-down or low-power options - may not be ideal for battery-powered devices
• Not available from US distributors (Mouser, Digi-Key)

Datasheet

Ordering (LCSC)

Motor drivers

TMC6300-LA

This is a relatively new IC and it's a perfect match! There generally aren't any other drivers (with integrated fets) that meet the requirements for the low-voltage and low-current motors used in this project.

Highlights:

• 2-11V DC motor supply input
• Up to 1.2A RMS
• Tiny (3x3mm QFN)

Datasheet

Product page

Motors

TODO

Firmware

TODO

License

This project is licensed under Apache v2 (see LICENSE.txt).

Copyright 2022 Scott Bezek

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.