Tangible Interaction / Non-Visual Interface / Hardware

Braille Wordie

Duration

Oct - Dec 2023 · 2 months

Type

Group Work · UC Berkeley

Skills

Tangible Interaction, Circuit Prototyping, 3D Modeling

Tools

Rhino, Arduino, 3D Printing

No screen, no cursor, no visual state. Braille Wordie is a modular tangible interface for blind children: every input is a block placed by hand, every output is a voice. We built it so braille practice could happen without a teacher in the room.

A two-month group project at UC Berkeley: 3D-printed letter blocks, snap-together boards, a three-button cluster and a speaker, driven by an Arduino. What follows is how we designed interaction that lives entirely in hands and ears.

Team demo video — the full interaction, from opening the box to spelling a word by hand.

A tactile skill can't be taught on a screen

Braille fluency is a motor skill: fingers learning to resolve dot patterns, corrected in the moment. An app can talk about braille, but it can't put dots under a child's fingertips. The humans who can are scarce, so the material itself had to become the feedback channel.

1
17 US states report a shortage of Visual Impairment teachers. At Kentucky School for the Blind, the student/teacher ratio reached 61:1.
2
Virtual classes made it worse: touch doesn't travel over video, and teachers couldn't get tactile materials into students' homes.
3
Traditional braille materials are mute. They give no real-time feedback, so students can't self-correct toward fluency.
4
Existing teaching aids are single-purpose and inflexible, one fixed exercise per object.

Why blocks, and not the obvious alternatives? An app can speak, but it can't put dots under a fingertip. A refreshable braille display does, but it is expensive, shows one line at a time, and is built for reading, not for building words by hand. Embossed cards are cheap and tactile, but they stay silent, the same no-feedback problem we started from. Blocks were the one form that gave touch, sound and rearrangement at once.

My part in it

Audio is the display, blocks are the input

The device is a small state machine a child can hold. Strip away the screen and three channels are left, each doing one job:

1
Input is physical placement: letter blocks dropped into board slots, boards snapped together. The system reads whatever the hands have built.
2
Output is speech: instructions, pronunciations, praise and corrections all arrive as audio. Sound plays the role a screen normally would.
3
Navigation is three buttons, back, select, forward, driving an audio menu. That cluster is the entire control surface.
Two boards connected to spell REDO, left hand on the button cluster while the right hand rests on the blocks

Designing for hands, not eyes

When the user can't glance at anything, every affordance has to survive a fingertip-only test. The decisions that carried the interface:

1
Buttons are told apart by shape, not labels: two triangular arrows flanking a round select. Direction reads through a fingertip before any sound plays.
2
Filled and empty read by touch: board wells carry a textured grid while block faces are smooth, so the state of a slot is obvious the moment a hand lands on it.
3
Each block is dual-coded, raised braille dots plus an embossed print letter, so a blind child and a sighted parent or teacher share the same object.
4
Onboarding needs no setup: a brightness sensor in the box triggers the welcome and first instructions when the lid opens. Unboxing is the first interaction, no adult required.
Close-up of a fingertip on the three-button cluster, triangular arrows and a round select button
Fingertips reading the raised dots on a letter block
A hand gripping a letter block above the board's textured well

Snapping boards together is the grammar

Each board holds two blocks, and boards connect side by side. A word is assembled in space: spell RE on one board, snap on a board holding DO, and the device plays the combined word. The linguistic structure lives in the physical arrangement, so “prefix” stops being an abstract idea, it's a board you attach. The same syntax was scoped to go further: an ED board for past tense, chains of boards for full sentences.

Two hands bringing a second board toward the first to spell REDO
Boards spelling UNDO after swapping the prefix blocks, RE blocks set aside
Scoped scenario diagram: snapping an ED board onto PLAY to form the past tense
Scoped scenario diagram: chaining boards into the sentence I AM AMY

Sized to hands, built around a microcontroller

1
Blocks are 30 × 50 × 12 mm with Ø8 mm dots, sized against child ergonomics: average hand length of 52-62 mm and a maximum internal grip diameter of 30 mm.
2
The working prototype is fully 3D-printed and Arduino-driven, modeled in Rhino, wired and assembled by the team.
3
The whole kit, boards, blocks and electronics, packs into one wooden case, so the object a child carries is also the object they learn with.

Each letter block carries an RFID tag, so the board knows exactly which letter was placed and plays the audio that matches the current task. The storage box senses when it is opened, through a change in light, and starts the spoken welcome and guidance on its own. The prototype's weak point was the wiring: audio and module-to-module data ran over wires, which made the experience slower and less intuitive than it should be.

3D-printed letter blocks beside the dimension drawing: 30 by 50 by 12 millimeters with 8 millimeter dots

Three sessions, one loop

Content is staged as Tutorial, meet the object; Basic, pick a lesson, spell a word, hear its pronunciation and meaning; Advanced, connect boards and transform words with prefixes. Every step closes the same loop: act with your hands, hear the result, correct, go again. That loop is what stands in for the teacher's “try again”.

Tutorial: opening the box triggers the welcome message
Basic session: the device introduces the lesson by voice
Basic session: audio task instruction, find the letter R block
Basic session: spelling RE with blocks, confirmed by voice
Basic session: hearing the definition of the word just spelled
Advanced session: following the audio instruction to switch the prefix

Did it hold up in real hands?

We tested and presented the prototype at the Jacobs Winter Design Showcase 2023 at UC Berkeley. Two findings changed the design. Sound that played the instant a block was placed, with no prompt first, confused people, which is why the flow became button-led with a spoken menu. And critics pointed out that our braille cells were too large to read with one fingertip, the opposite of how braille is actually read, so the next version should use standard-size cells that carry over to real books.

Demoing the working prototype

What screen-less interaction taught me

1
State must be announced, not shown. Without a screen, whatever the system doesn't say out loud simply doesn't exist for the user, so feedback design becomes the whole interface.
2
Affordances do the work of UI copy. Shape, texture and size have to explain the system by themselves, there is no tooltip to fall back on.
3
Recovery has to be physical. A wrong block must be as easy to lift out as it was to place, and the system has to stay calm while hands rearrange the world.

These are the questions every embodied product, a robot, a wearable, an appliance, has to answer: how does a machine make its state legible, and its mistakes correctable, to a human body rather than a pair of eyes?

What's next

Two directions we scoped but didn't build: richer linguistic scenarios on the same physical syntax (past tense, sentence writing), and an AI text-to-audio learning assistant that would let any book become braille practice material.

Concept render of the production design, color-coded blocks on two connected boards