A BRAILLE DISPLAY THAT COSTS A FRACTION OF THE COMMERCIAL ONES BECAUSE IT USES A SINGLE MOVING CELL
A refreshable braille display normally costs thousands — this prototype uses one moving cell and a grid of touch sensors, and its team estimates that could cut the cost by over ninety percent.
Open-hardwareAutomation
Built withESP323D printing
- difficulty
- ●●●●○
- time
- a weekend-plus
- license
- BTAC v1.2.1 (custom copyleft)
- repo
- repo ACTIVE56 stars
●●●●○ · a weekend-plus · BTAC v1.2.1 (custom copyleft) · 56 stars · repo ACTIVE
WHAT YOU’LL NEED
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COMPAREE VERDICT
BrailleTouch tackles the price of refreshable braille displays with a different idea: instead of a row of expensive cells, it uses one physical braille cell and a cheap touch-sensor matrix that acts as a line of "virtual" cells. You touch a position and the single cell under your other finger shows that character. The repository has the CAD for a 3D-printed cell whose eight dots are each raised by a small phone vibration motor, driven by L9110 drivers, a 74LS04 inverter and an ESP32, plus 20 CAD assembly images and a STEP reference model. The touch matrix is still under development and the published ESP32 firmware is an early servo-based Bluetooth prototype, so this is a research project in active development, not a kit. The team estimates the total device cost could drop by more than ninety percent versus current displays.
IN THE REPO
GOOD TO KNOW
- —Full mechanical CAD for the single braille cell is in the repository, with STEP files.
- —A set of 20 assembly images, an assembly PDF and a STEP reference model show how the cell goes together.
- —Prototype ESP32 firmware (Bluetooth serial) is included, but it was written for the earlier servo-driven cell; for the vibration-motor cell you write your own motor-control function. Screen-reader support (NVDA, BRLTTY, BrailleBack) is planned, not finished.
- —No bill of materials as a single file — parts are named in the assembly guide and README.
- —Each of the eight dots is driven by a phone vibration motor (via L9110 drivers), which you source yourself.
- —Licensed under the project's own copyleft BTAC licence, which permits commercial use as long as derivatives and innovations stay open.
Parts to buy
8 itemsFrom our check of the build. Exact quantities and part numbers are in the creator’s BOM.
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
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Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Study the 20 CAD assembly images, the assembly PDF and the STEP reference model in the repository before ordering anything. (The images are CAD renders, and there is no separate BOM — parts are named in the cell README.)
- 2.Source eight matching phone vibration motors (one per dot) and test one in a printed motor mount before building the whole cell around them.(Each of the eight motors raises one dot, and the motors are not specified by part number; if they do not fit the printed mount or lack torque, the dots will not lift.)
- 3.Print the cell housing and test-fit the motor and pins before final assembly.(Tolerances are tight; a test print will save you from reprinting after gluing parts.)
- 4.Prototype the touch sensor array yourself — start with a breadboard and a single sensor before committing to a full grid.(The array is not plug-and-play; you will be choosing sensor modules and testing spacing.)
- 5.Flash the ESP32 firmware and test the cell over Bluetooth serial, adapting the motor-control function to your vibration-motor cell.(The prototype firmware is in the repository; test it over Bluetooth serial — screen-reader support is still on the roadmap.)
KNOWN ISSUES
- The cell needs eight phone vibration motors (one per dot) and they are not specified by part number — you will spend time finding ones that fit the mount, and may need to adjust the CAD if yours differ.
- There is no tested bill of materials or recommended capacitive touch sensor model, and no touch-matrix schematic in the repository, so you will be designing that part yourself.
- The cell mechanics are fiddly — small parts, tight pin alignment, and a motor that must be centred — expect iteration and test prints.
- The touch sensor array is still under development — the README only describes the idea (about 200 positions on the ESP32 touch pins), with no schematic or finished board, so layout, spacing and wiring are on you.
- The ninety percent saving claim is the project's own; actual cost depends entirely on what you pay for the ESP32, sensors, and how many attempts the motor mount takes.
- This is not a drop-in replacement for a commercial display — it is a research prototype with a novel interaction model, and some users may find the single-cell concept harder to learn than a traditional forty-cell display.
Does this actually work with normal screen readers?
Not yet. Compatibility with NVDA, BRLTTY and BrailleBack is a stated goal, but the current ESP32 firmware is an early Bluetooth-serial prototype, not a standard braille-display driver.
What if I cannot find a vibration motor that fits?
You will need to modify the CAD for the motor mount — the STEP files are in the repository, so it is possible, but it adds a day or more to the build.
Is there a pre-made PCB for the touch sensor array?
No — the touch-sensor matrix is still under development (the idea is ~200 positions on the ESP32's touch pins), so you will be designing and breadboarding it yourself.
How long does it take someone who has never built a braille cell before?
Longer than a weekend — the cell itself is a weekend with test prints, and the sensor array will take another half-day minimum, longer if you need to order different sensors after testing.
Can I sell devices built from this?
Yes, with conditions. The project uses its own copyleft licence (BTAC), which allows commercial use as long as your derivatives and improvements stay open and freely accessible. Read the LICENSE file before selling.
Community builds
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Discussion1
FROM THE COMPAREE TEAM
The whole idea is one moving cell instead of forty expensive ones — and the project estimates the total device cost could drop by more than ninety percent. If you have used a traditional multi-cell display before, how big a shift would this single-cell interaction model actually be?
BrailleTouch team
The BrailleTouch team built this to address the cost barrier of refreshable braille displays, which typically run into thousands of dollars because of the mechanical complexity of multi-cell arrays. The single-cell design with a touch grid is a research prototype exploring a radically cheaper interaction model.
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DISCLAIMER
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- Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
- Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
CompareeTEAM1mo agoedited
Practical notes from our verification: the repository contains the mechanical CAD for the braille cell (STL, STEP and SolidWorks files), 20 numbered CAD assembly images and a short written assembly sequence, plus a short video clip of the cell in action. The cell raises its eight dots with eight salvaged phone vibration motors, L9110 motor drivers, a 74LS04 inverter and an ESP32 — motor fit varies with what you salvage, so expect to adjust the printed parts. The touch sensor matrix that acts as the virtual line of cells is still marked as under development, with no finished PCB, so you are prototyping that part yourself. The published firmware is an early Bluetooth serial prototype written for a servo-driven cell; compatibility with screen readers such as NVDA, BRLTTY and BrailleBack is listed as a goal, not a delivered feature. The licence is the project's own BTAC licence, not a standard open-source one. This is a genuinely novel approach to a real accessibility problem, but it is a research prototype in active development, not a kit. Correction (4 October 2026): we re-checked this page line by line against the project's own repository, documentation and videos, and fixed errors in earlier versions.