Important
2026-02-20 This device is undergoing final user and maker validation testing before being added to the Makers Making Change Assistive Device Library. All of the information required to build the device is available in the repository, but it is not yet available to be requested as a volunteer maker build.
The Shrub Hub is an digital switch interface that allows a user to connect up to three 3.5mm assistive switches to a digital device like a computer or mobile phone. It has five modes, and can send keystrokes, mouse clicks, and media control commands, with five outputs per mode. It is designed to provide digital access to users using assistive switches, and to be low cost and very easy to build.
It is designed for use by those who have difficulty using traditional input devices like a computer mouse and may be especially useful for those with limited finger or hand dexterity.
The device is comprised of off-the-shelf electronics and 3D printed parts. There is no soldering or complicated assembly involved in building the device.
The Shrub Hub is open assistive technology (OpenAT). Under the terms of the open source licenses, the device may be built, used, and improved upon by anyone.
The overall cost of materials is about $35 (plus $8 for component shipping).
This is an open-source assistive technology, so anyone is free to build it. All of the files and instructions required to build the device are contained within this repository. Refer to the Maker Guide below.
Note
This device will be available for request as a volunteer maker build after final user validation is complete.
You may also submit a build request through the Makers Making Change Assistive Device Library Listing to have a volunteer maker build the device. As the requestor, you are responsible for reimbursing the maker for the cost of materials and any shipping.
If you have the skills and equipment to build this device, and would like to donate your time to create the device for someone who needs it, visit the MMC Maker Wanted section.
The Maker Guide contains all the necessary information to build this device, including tool lists, assembly instructions, programming instructions and testing.
The Bill of Materials lists all of the parts and components required to build the device.
All of the files and individual print files can be found in the /Build_Files/3D_Printing_Files folder.
Reference the Assembly Guide section of the Maker Guide for the tools and steps required to build the device.
As open source assistive technology, you are welcomed and encouraged to improve upon the design.
| Document | Version | Link |
|---|---|---|
| Design Rationale | 1.0 | Shrub_Hub_Design_Rationale |
| Maker Guide | 1.0 | Shrub_Hub_Maker_Guide |
| Bill of Materials | 1.0 | Shrub_Hub_Bill_of_Materials |
| User Guide | 1.0 | Shrub_Hub_User_Guide |
| Quickstart Guide | 1.0 | Shrub_Hub_Quickstart_Guide |
| Changing Outputs Guide | 1.0 | Shrub_Hub_Changing_Outputs_Guide |
| Changelog | 1.0 | Changelog |
Copyright (c) 2026 Neil Squire Society.
This repository describes Open Hardware:
- Everything needed or used to design, make, test, or prepare the Shrub Hub is licensed under the CERN 2.0 Weakly Reciprocal license (CERN-OHL-W v2) or later .
- All software is under the GNU General Public License v3.0 (GPL-3.0).
- Accompanying material such as instruction manuals, videos, and other copyrightable works that are useful but not necessary to design, make, test, or prepare the Shrub Hub are published under a Creative Commons Attribution-ShareAlike 4.0 license (CC BY-SA 4.0) .
You may redistribute and modify this documentation and make products using it under the terms of the CERN-OHL-W v2. This documentation is distributed WITHOUT ANY EXPRESS OR IMPLIED WARRANTY, INCLUDING OF MERCHANTABILITY, SATISFACTORY QUALITY AND FITNESS FOR A PARTICULAR PURPOSE. Please see the CERN-OHL-W v2 for applicable conditions.
Source Location: https://github.com/makersmakingchange/Shrub-Hub
The Shrub Hub enclosure, software, and documentation was designed and created by the Neil Squire Society.
The Shrub Hub incorporates the Adafruit TRRS Trinkey - USB Key for Assistive Technology, a commercially available open source hardware device available for purchase through Adafruit and its distributors worldwide. The design of the TRRS Trinkey was a collaboration between ATMakers.org and Adafruit. The hardware design files are released under the CC-BY-SA 3.0 license and are available at https://github.com/adafruit/Adafruit-TRRS-Trinkey-PCB. This device is also certified open hardware by the Open Source Hardware Association (OSHWA), certification US002639.
The Shrub Hub is programmed in CircuitPython using the Mu Python Editor.
The documentation template was created by Makers Making Change / Neil Squire Society. It is available at the following link: https://github.com/makersmakingchange/OpenAT-Template
- Brad Wellington. Shrub Hub Enclosure, firmware, documentation. Neil Squire Society / Makers Making Change.
- Bill Binko. TRRS Trinkey PCB design and Learning Guide. ATMakers.org.
- Chris Young. TRRS Trinkey PCB Design. ATMakers.org.
- Eric Chau. Testing. Neil Squire Society / Solutions.
- Jake McIvor. Documentation, testing. Neil Squire Society / Makers Making Change.
- Limor Fried. TRRS Trinkey PCB Design. Adafruit.
- Liz Clark. TRRS Trinkey Learning Guide. Adafruit.
- Jody Dickerson. Testing. Neil Squire Society / Solutions.
- Josie Versloot. Testing. Neil Squire Society / Makers Making Change.
- Stephan Dobri. Testing. Neil Squire Society / Makers Making Change.
The Shrub Hub has been certified as open source hardware by the Open Source Hardware Association under the OSHWA UID CA000073.
Makers Making Change is a program of Neil Squire, a Canadian non-profit that uses technology, knowledge, and passion to empower people with disabilities.
Makers Making Change leverages the capacity of community based Makers, Disability Professionals and Volunteers to develop and deliver affordable Open Source Assistive Technologies.
- Website: www.MakersMakingChange.com
- GitHub: makersmakingchange
- Bluesky: @makersmakingchange.bsky.social
- Instagram: @makersmakingchange
- Facebook: makersmakechange
- LinkedIn: Neil Squire Society
- Thingiverse: makersmakingchange
- Printables: MakersMakingChange
For technical questions, to get involved, or to share your experience we encourage you to visit our website or contact us.