MMC R&D Summer Update

July 28, 2022

Over the summer, the Makers Making Change (new window) Research and Development team has been hard at work on a variety of projects. Here’s a rundown of some of the larger projects our R&D team are currently working on:

OpenAT Joysticks

The Xbox Adaptive Controller is great but finding compatible joysticks to control the left and right stick can be challenging due to cost, availability, or both. We have recently started a new project to create a line of modular OpenAT Joysticks to address this need.

Currently, we are wrapping up the research phase and are transitioning to the design input and conceptual design phase. We’ve identified several existing designs that can be used as-is or as a starting point. The primary goal is to create several options based on off-the-shelf (OTS) components like thumbsticks (new window) and joysticks (new window), to be connected using 3.5 mm TRRS cables (new window) and/or microcontrollers (new window), and then look at the potential for custom designs to address underserved use cases (e.g., very low force, very small range of motion). The joysticks will include easily mountable 3D printed enclosures and a range of customizable, modular toppers.

If you have any suggestions, feedback, features you wish your current or future joystick would have, or would be keen to test prototypes, let us know on the forum (new window).

OpenAT 3D Printed Toy

the Open AT toy in progress design

The goal of the OpenAT 3D Printed Toy is to create a maker-friendly switch compatible toy that provides multiple, selectable options for stimulation (e.g., light, sound, movement). Hacked commercial toys don’t typically offer the ability to select between stimuli, and commercial versions that do can be very expensive.

The type of stimuli can be selected using switches on the Toy. The Toy can then be activated using an assistive switch connected to a standard 3.5 mm jack (new window). The goal is to make the design modular to allow for different toy toppers to be made by the maker to suit the interests of the user.

A secondary goal for this project is that the build itself provides a good STEM learning opportunity. There is an opportunity to learn and develop skills related to CAD modelling, soldering, simple circuits, and programming.

Any suggestions for toy features or design ideas for “toppers” would be greatly appreciated. Any feedback on the robot theme, smiling ring of lights, electronics control panel layout, or other potential improvements for the design would be very helpful as well.

More information is available on the Design Challenges Forum (new window).

Freedom Wing 2.0

Freedom Wing 2.0

We’ve partnered with AbleGamers (new window) to create a variation of the FreedomWing (new window) to enable more gamers to utilize their powerchair joystick as a gaming joystick. The original FreedomWing works great but there are two limitations that prevent some potential users from utilizing the device. First, the joystick must be unplugged from the power chair and plugged into the Freedom Wing. This can limit a user’s independence, as not everyone has someone readily available who can perform the cable swap for them. Secondly, the connection to the FreedomWing is only compatible with certain joysticks, so it is not possible for many users to utilize the device with their setup.

The current plan is to create a variation of the FreedomWing that is able to connect with a Bluetooth Mouse module on a powerchair and convert the mouse signals into joystick commands. Our Embedded Systems Designer Milad had already created a similar solution (new window) for a user in France and we are in the process of testing and expanding this setup.

Comments, feedbacks, etc., can be added to the MMC Forum (new window).

LipSync 3.0

We have finalized a major code update for the original LipSync hardware. The bulk of this development work was completed last year, and we are now ready to release it officially. The LipSync 3.0 software incorporates a number of improvements:

Drift Reduction

Drift reduction was the focus of this major update the original LipSync hardware. Drift, or undesirable cursor motion, was one of the main issues with the original LipSync. After a root-cause failure analysis, we concluded that the characteristics of force sensing resistors (FSRs) are the main contributors to the drift issue. We decided that the improved version of the damping code introduced in 2020 Hackathon to reduce and filter the output data. We also implemented a joystick lift code which makes sure the value of the opposite FSR is reduced during each joystick movement. The damping and joystick lift code were able to significantly reduce the drift introduced by the hardware and we were able to verify this thanks to feedback from our users.

Serial Application Programming Interface (API)

We implemented a serial API with more than 20 endpoints which would allow the end user to customize their device through a third-party application such as a Serial client software. The API has also improved the debugging and troubleshooting process of non-functional LipSyncs by providing debugging endpoints that can output raw sensor data.

Improved update and setup process

The new software update provides features such as automatic configuration which uses LipSync model and version numbers to automatically configure Bluetooth module or reset the settings if it’s required. This can simplify the setup process and let makers or end users to switch between different LipSync base software.

Updated the 3D Printed Housing files

We updated the LipSync housing to provide more visual feedback to the end users and at the same time it improved the assembly process by making it less challenging for makers to insert the electronic components in the housing.

Improved Drag and Scroll Visual Feedback

We added improved visual feedback to make it easier for the user to determine when drag and scroll modes are activated during longer sip and puff inputs. The LED now changes color when a sip or puff has been held long enough so a user doesn’t have to mentally keep track of the elapsed time.

Separate Sip and Puff thresholds

The original LipSync used a single pressure threshold for both sip and puff. This limited some user’s abilities as not everyone can sip and puff equally well. The thresholds can be now set separately to better match a user’s abilities.

Code Optimization

The LipSync software was optimized to improve its performance and use the available resources in a more efficient manner. This was achieved by implementation of an improved software structure and making use of data structures which can minimize the memory usage. A structured source code and improved documentation will help us and other makers to maintain and improve their LipSync experience going forward.

Updated Documentation and User Guides

The LipSync documentation and guides were updated to provide the necessary information about the enhanced features to assist makers and end users during the assembly process or the usage.

The latest code is available at the repositories listed below:

If you would like some help updating the code on your device, reach out to your local maker or us.

LipSync X

The LipSync X alpha version in front of a laptop

Last fall, we started overhauling the design of the LipSync to incorporate user feedback and address some limitations to the original hardware (like those pesky, expensive, drift-inducing FSRs). Our main goal was to make the device easier to use and more reliable – primarily reducing the force required to move the mouthpiece and making the movement more reliable.

We created a custom joystick based on a 3D Magnetic Hall Effect sensor. This design enabled us to reduce the amount of force required to operate the joystick from about 200 grams force with the original LipSync down to 20 grams force.

The design uses several commercially available STEMMA QT modules in addition to custom printed circuit boards (PCBs). This approach provides the ability to use surface mount sensors without having to solder them – the modules are connected with cables.

The design is currently a fully functional prototype that has been tested with a group of 5 users. We are in the process of incorporating the user feedback to finalize the code and the enclosure for the design.

The design is hosted on GitHub (new window). If you have any ideas, suggestions, or are interested in testing the finalized version, reach out and contact us (new window).

OpenAT Templates and Guides

We feel that one of the keys to success of Open Assistive Technology is making sure that all the information and files – the know-how – to build, use, and improve upon a design is complete, comprehensive, properly licensed, and published.

Documentation may not be the most exciting part of completing a project, but it is critically important. To make the process of publishing the know-how for a project a bit easier, we have been developing an OpenAT project template – a set of folders for collecting all the design files, build files, photos, and supporting documentation for a project.

The template also includes individual templates for the various documentation files (e.g., Assembly Guide, User Guide). These templates incorporate best practices from the Open Source Hardware Association (new window) and the Open Know-How Specifications (new window) and will also include an Open Know-How manifest file (new window). The template is hosted on GitHub as a template repository – you can create a new repository using the template or just download the files directly.

We’re very interested in getting feedback on these templates, especially around ideas for simplifying and streamlining the documentation process. Please have a look at the templates on GitHub (new window). You can leave feedback as issues or comments on the repository, or on the MMC Forum (new window).

This post originally appeared on the Makers Making Change (new window) website.