How To Create Benny's 2-Switch Kit
DIY Guide: How to Build Benny’s 2-Switch Kit
At the NARBE Foundation, our mission is simple: make accessibility open, low-cost, and available to absolutely everyone.
We’ve heard from amazing communities in Canada, the UK, Europe, Australia, and Mexico asking how they can replicate our setup. Because we can’t ship physical kits outside of the United States, we wanted to put the power directly into your hands.
The best news? Our entire system is completely open-source.
Our switch kits cost about $60 to put together (In the U.S.), compared to $200 or more from other manufacturers.
Benny's switch kit is a simple set of physical buttons that allows someone with limited mobility to control a web app using just one or two movements. Instead of a keyboard or mouse, a person can press a large button with their hand, foot, elbow, or any movement that works for them.
Benny's Hub is a free website hosted by the NARBE Foundation, where people who use one or two switches can play games and explore activities designed specifically for them. Every game on the Hub was built for switch access, but you can also play using a touchscreen, mouse, or any other assistive technology that can run an internet browser.
Inspired by Ben's journey back to communication, more independence, and playing video games again, our family founded the NARBE Foundation to help others find joy and access to the games they love, even when traditional controllers aren't an option.
💻 Device Compatibility: What Do You Need?
We get two questions more than any others:
- What device does Ben use? and
- Will this kit work with my device
Ben's Personal Setup: Ben currently uses a Windows Surface tablet for his daily setup. The switches (buttons) are attached with velcro on a headband or on his wheelchair headrest for easier clicking.
If you'd like to find out more about Ben's custom software and set up, you can view the NARBE House blog here to find out more.
Universal Compatibility: Benny’s Accessibility Hub is a completely free web app. Any device—whether it is a tablet, computer, or phone—that can run a Google Chrome browser will work.
Whether you are running Windows, macOS, iOS, or Android, if you can open Chrome, you can play!
🔄 The Evolution of Ben's Setup
People often ask us about the history of Ben's gear and when his various setups came into play. Here is how his setup has evolved over time:
The Early Days: Premium Commercial Hardware
When Ben first started his accessibility journey, his original configuration relied on high-end commercial hardware. He used the Swifty USB Switch Interface paired with two Orby Switches from Origin Instruments.
While this bundle is incredibly durable and high-quality, purchasing commercial interfaces and multiple switches carries a premium price tag that can be a major financial barrier for many families (this set up can cost around $200).
The Current Setup: Affordable & Open-Source
To make play accessible to everyone, the NARBE Foundation partnered with Switched Toys to design custom, 3D-printed switch kits specifically optimized for Benny’s Hub. This is the exact open-source blueprint we use today, and it costs just a fraction of the price of commercial alternatives.
🛠️ The Blueprint: Our DIY Shopping List
If you are looking to source the exact items we package into our standard U.S. kits, here is your official shopping list:
The Buttons: We use durable, colorful accessibility switches from
Switched Toys The Brain (Microcontroller): This is the Adafruit TRRS Trinkey (we highly recommend grabbing the matching plastic clear case to protect it). It looks like a tiny USB thumb drive with a headphone jack on the end. Get the
TRRS Trinkey here The Adapter Cable: A 3.5mm Stereo Male to Dual 3.5mm Mono Female Cable. This plugs into the Trinkey and splits the signal into two separate jacks—one for each button. Get the
splitter cable here on Amazon The Free Software: You will load our pre-written code onto the Trinkey so it knows that Button 1 means "Spacebar" and Button 2 means "Enter." You can download
Benny's Trinkey Code on GitHub
How To Set Up The Trinkey
Credit: @loretodumitrescu1486
Website: zeroday.camp
🌍 Sourcing the Kit Outside the United States
Website: zeroday.camp
If you live abroad, you don’t need to worry about massive international shipping fees. You can find these exact components right in your backyard through local electronics shops and amazing regional charities.
1. Finding the "Brain" (Adafruit TRRS Trinkey) Globally
"Adafruit TRRS Trinkey - USB Key for Assistive Technology"
Adafruit is a U.S. company, but they have authorized local distributors worldwide. Search for Product ID: 5954 at these regional shops:
Canada: DigiKey Canada
United Kingdom: The Pi Hut or Pimoroni
Germany & Central Europe: BerryBase, Eckstein Electronics, or Mouser Germany
Australia: Core Electronics or Little Bird Electronics
Mexico: DigiKey México or Mouser México
2. Finding the Splitter Cable Globally
You can find this adapter cable on almost any regional version of Amazon or local electronics storefront. Just search for:
English: "3.5mm stereo male to dual 3.5mm mono female splitter cable"
German: "3.5mm klinke stereo auf 2x mono kupplung"
Spanish: "Adaptador divisor de jack de audio de 3.5mm estéreo a dos entradas mono"
3. Finding Buttons & Local Support Near You
Instead of ordering plastic switches from across the ocean, reach out to these incredible regional assistive technology networks for low-cost, 3D-printed alternatives:
🇨🇦 In Canada (Makers Making Change): An incredible resource with an online library of open-source accessibility switches. You can request a switch on their website, and a local volunteer "maker" will 3D-print it for you, charging only the bare cost of materials (usually $10 - $25 CAD).
🇬🇧 In the United Kingdom (SpecialEffect & OneSwitch): SpecialEffect is a world-class charity offering equipment advice via GameAccess. For affordable, sturdy local switches, check out OneSwitch or Inclusive Technology.
🇪🇺 In Europe (REHAB-LAB, Gaming ohne Grenzen & FabLabs): REHAB-LAB connects healthcare facilities with fabrication labs to let individuals 3D-print their own custom assistive devices. In Germany, Gaming ohne Grenzen provides fantastic inclusive play resources. You can also take open-source switch designs to any local community Makerspace or FabLab, where tech volunteers are often thrilled to help families for free.
🇦🇺 In Australia (Technical Solutions & TAD Australia): Technical Solutions Australia provides a massive catalogue of local disability switches. If you need custom modifications, TAD Australia connects families with skilled volunteers who build and adapt custom gear.
- 🇲🇽 In Mexico (Teletón México & Maker Communities): The Teletón México network is an incredible resource for rehabilitation and assistive technology guidance. For a DIY approach, Mexico’s growing network of university FabLabs and makerspaces can easily 3D-print open-source switch enclosures.
🔍 Global Search Keywords: Finding Help in Your Language
Because healthcare and technology terms vary wildly across borders, finding the right local support can sometimes feel like a translation puzzle. If you are trying to find adaptive professionals or organizations in your country, try plugging these regional keywords into your search engine:
In English-Speaking Regions (UK, Australia, New Zealand, Canada): Search for “Assistive Technology Specialists,” “Independent Living Centres (ILCs),” “Alternative and Augmentative Communication (AAC) clinics,” or “Community Makerspaces.”
In Europe (French/German/Spanish): Try terms like “Ergotherapeuten” (Occupational Therapists in Germany), “Orthophonistes” (Speech Therapists in France), “Logopedas” (Speech Therapists in Spain), “Aides techniques” (Technical aids), or “Centres d'information sur les aides techniques.”
In Latin America: Look up “Tecnología Asistiva,” “Terapeutas de Lenguaje” (Speech Therapists), “Terapeutas Ocupacionales,” “Centros de Rehabilitación Integral,” or local “Laboratorios de Fabricación (FabLabs).”
⚠️ Important Note: If you already have commercial switches, they are often simple hardware buttons with no built-in software to communicate with a computer on their own. To use them with Benny's Hub, you will likely still need to plug them into our Adafruit TRRS Trinkey setup so the Trinkey can translate those button presses into the Spacebar and Enter commands the Hub requires.
📱 Using the Kit with iPads, Tablets, or Phones
Because the TRRS Trinkey uses a standard, rectangular USB plug (USB-A), you will likely need a small adapter to plug it into your mobile phone or tablet. These are inexpensive, easy to find, and plug directly into your device's charging port:
For Newer iPads & Android Devices (USB-C Port): You need a USB-C to USB Adapter (sometimes called a USB-C OTG adapter).
For Older iPhones & iPads (Lightning Port): You need an Apple Lightning to USB Camera Adapter.
⚠️ Intended Use & Safety Disclaimer
While Benny’s Accessibility Hub includes a customizable phrase board and a predictive text keyboard, this web application is for recreational and entertainment purposes only. Our focus is squarely on providing fun entertainment tools, engaging activities, and accessible switch games. It is not medical-grade software, nor is it meant to replace official AAC tools.
What is AAC? AAC stands for Augmentative and Alternative Communication. It refers to a specialized spectrum of dedicated devices, software, and communication methods used by individuals who cannot rely fully on verbal speech to express themselves. Reliable, medical-grade AAC software is critical for essential day-to-day needs, healthcare settings, and communicating safety-critical information.
Safety Guidelines:
Never plug these custom switches or microcontrollers into medical devices or life-support equipment.
Do not rely on Benny’s Hub for essential medical, emergency, or critical safety communication.
Always consult a professional: We highly recommend collaborating with a certified Assistive Technology (AT) professional, Speech-Language Pathologist (SLP), Occupational Therapist (OT), or other qualified healthcare provider when seeking long-term communication and access solutions tailored to an individual’s unique medical and developmental needs.
Need a Hand?
We know jumping into the DIY world can feel a bit intimidating if you’ve never done it before. If you are a family trying to set this up and you get stuck on any step, please don't hesitate to reach out to us at info@narbefoundation.org. We are all in this together!
