Hackaday Prize Entry: Crowdsourced Tactile Interfaces

Your microwave, your TV, and almost the entire inventory of Best Buy have one thing in common: they all uses membrane switches for user interaction, and that means these devices are inaccessible for the blind. This project for the Hackaday Prize is going to change that by building a crowdsourced effort to design Braille keypads for thousands of appliances.

There are two aspects of this project that are exceptionally interesting, the least of which is how to make Braille keypads for a microwave. This is done with a 3D printer using a flexible or semi-flexible filament. These keypads are designed to overlay the membrane keypad on consumer electronic devices, and the initial testing reveals these keypads are robust and useful enough for blind users.

A 3D printed overlay for a microwave is simple, though. The big question is how these overlays are designed. For this, the project suggests a crowdsourced effort of hundreds of designers turning photographs of keypads into Braille overlays. The process begins with a few pictures of a keypad with a reference object – for example, a dollar bill. These photographs are scaled to the correct dimensions, a few outlines are made, and the buttons with Braille text are designed. It’s a brilliant use of people who have just enough experience in Photoshop to be useful, and since this is a crowdsourced effort, work isn’t duplicated. The keypad overlays for one specific make and model of microwave can be printed over and over again, bootstrapping an effort to make membrane keypads useful for all blind people.

Hackaday Prize Entry: Modular, Low Cost Braille Display

A lot of work with binary arithmetic was pioneered in the mid-1800s. Boolean algebra was developed by George Boole, but a less obvious binary invention was created at this time: the Braille writing system. Using a system of raised dots (essentially 1s and 0s), visually impaired people have been able to read using their sense of touch. In the modern age of fast information, however, it’s a little more difficult. A number of people have been working on refreshable Braille displays, including [Madaeon] who has created a modular refreshable Braille display.

The idea is to recreate the Braille cell with a set of tiny solenoids. The cell is a set of dots, each of which can be raised or lowered in a particular arrangement to represent a letter or other symbol. With a set of solenoids, this can be accomplished rather rapidly. [Madaeon] has already prototyped these miniscule controllable dots using the latest 3D printing and laser cutting methods and is about ready to put together his first full Braille character.

While this isn’t quite ready for a full-scale display yet, the fundamentals look like a solid foundation for building one. This is all hot on the heels of perhaps the most civilized patent disagreement in history regarding a Braille display that’s similar. Hopefully all the discussion and hacking of Braille displays will bring the cost down enough that anyone who needs one will easily be able to obtain and use one.

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The Politest Patent Discussion, OSHW v. Patents

We’ve covered [Vijay] refreshable braille display before. Reader, [zakqwy] pointed us to an interesting event that occured in the discussion of its Hackaday.io project page.

[Vijay] was inspired by the work of [Paul D’souza], who he met at Makerfaire Bangalore. [Paul] came up with a way to make a refreshable braille display using small pager motors. [Vijay] saw the light, and also felt that he could make the vibrating motor display in such a way that anyone could make it for themselves at a low cost.

Of course, [Paul], had patented his work, and in this case rightly so. As jaded as we have become with insane patent trolls, our expectation on receiving the tip was that [Paul] had sued [Vijay] out of house and home and kicked his dog while he was at it. A short google search shows that [Paul] is no patent troll, and is a leader in his field. He has done a lot to help the visually impaired with his research and inventions.

Instead we were greeted by a completely different conversation. [Paul] politely mentioned that his lawyer informed him that in order to protect his IP he needed to let [Vijay] know exactly how the information could be used. No cease and desist, in fact he encouraged [Vijay] to continue his open research as long as he made it clear that the methods described could not be used to make a marketable product without infringing on [Paul]’s patents. They’d need to get in touch with [Paul] and work something out before doing such.

[Vijay] responded very well to this information. His original goal was to produce a cheap braille display that could be made and sold by anyone. However, he did use [Paul]’s work as a basis for his variation. Since [Paul]’s commercial interests relied on his patent, there was a clear conflict, and it became obvious to [Vijay] that if he wanted to meet his goal he’d have to pick a new direction. So, he released his old designs as Creative Commons, since the CERN license he was using was invalidated by [Paul]’s patent. He made it very clear that anyone basing their work off those designs would have to get in touch with [Paul]. Undaunted by this, and still passionate about the project, [Vijay] has decided to start from scratch and see if he can invent an entirely new, unprotected mechanism.

Yes, the patent system is actually encouraging innovation by documenting prior work while protecting commercial and time investments of beneficial inventors. Well. That’s unexpected.

Kudos to [Paul] for encouraging the exploration of home hackers rather than playing the part of the evil patent owner we’ve all come to expect from these stories. Also [Vijay], for acting maturely to [Paul]’s polite request and not ceasing his work.

Refreshable Braille Display and Braille Keyboard

Only about 10% of blind people around the world can read Braille. One primary reason is the high cost of Braille displays. The cost is a result of their complexity and reliability – required to ensure that they are able to handle wear and tear.

[Vijay] has been working since 3 years on a Refreshable Braille Display but has only recently been able to make some substantial progress after teaming up with [Paul D’souza]. During his initial experiments, he used dot matrix printer heads, but the current version uses tiny vibration motors as used in mobile phones. He’s converting rotary motion of the tiny motors in to linear movement for pushing the Braille “cell” pins up and down. The eccentric weight on the vibration motor is replaced with a shaped cam. Continuous rotation of the cam is limited by a stopper, which is part of the 3D printed housing that holds the motors. Another 3D printed part has three cam followers, levers, springs and Braille pins rolled in one piece, to create half a Braille cell. Depending on the cam position, the pins are either pushed up or down. One Braille cell module consists of two cam follower pieces, a housing for six vibration motors, and a cover plate. Multiple modules are chained together to form the display.

The next step would be to work on the electronics – in particular ensuring that he is able to control the motor movement in both directions in a controlled manner. Chime in with your comments if you have any ideas. The 3D design files are available from his Dropbox folder.

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Hackaday Prize Entry: A Braille Computer

As with all devices meant for a very small percentage of the population, computing equipment for the blind is very, very expensive. A Braille typewriter – a relatively simple machine that puts dots on a piece of paper – costs about $700 USD. Need a Braille interface for a computer? You can buy a 16-cell wide Braille output for $1600, and high-end models with an integrated keyboard go up to $5000.

For his Hackaday Prize entry, [Haydn Jones] is building a simpler and cheaper Braille computer. It’s not just a single line of text at a time; this computer will have a display that will output an entire page of Braille at a time.

The current solutions for a computer to Braille interface use small electromechanical cells for each character. That’s six individual pins for each character, multiplied by the number of cells on the display. Doing a full-page display with this type of mechanism, but [Haydn] has another idea. Instead of controlling each pin individually, all of the pins on the display will be controlled by a CNC-like mechanism. The pins themselves will be mechanical SR latches, better known as the mechanism in a ball point pen.

A display is only half of the IO of a computer, and for the input portion of his build, [Haydn] is also building a Braille keyboard. This doubles as a binary or hexadecimal keyboard, but the idea is very similar to a proper chorded Braille keyboard. It’s a simple enough build; just a few key switches and a microcontroller.

The 2015 Hackaday Prize is sponsored by:

BRAIGO – A Lego Braille Printer


Accessibility devices tend to be prohibitively expensive, and it’s always nice to see a hacker apply their skills to making these devices more affordable. BRAIGO is a low cost braille printer by [Shubham Banerjee]. He built the printer using parts from the LEGO Mindstorms EV3 kit, with a few additions. This LEGO kit retails for $349, and a standard braille printer costs over $2000.

The BRAIGO print head uses weights and a pin to punch holes in standard calculator paper rolls. LEGO motors are used to feed the paper and align the head for accurate printing. It takes about 5 to 7 seconds to print each letter, which are entered on the Mindstorms controller.

While this is a great prototype, [Shubham] intends to continue development with the goal of creating an affordable braille printer. He’s a bit swamped with media requests right now, but is working on releasing BRAIGO as an open source project so others can contribute. It’s an impressive project, especially for a 12 year old student. After the break, watch the BRAIGO do some printing.

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Using A Computer To Read Braille


[Matthiew] needed to create a system that would allow a computer to read braille. An electromechanical system would be annoying to develop and would require many hardware iterations as the system [Matthew] is developing evolves. Instead, he came up with a much better solution using a webcam and OpenCV that still gets 100% accuracy.

Instead of using a camera to look for raised or lowered pins in this mechanical braille display, [Matthiew] is using OpenCV to detect the shadows. This requires calibrating the camera to the correct angle, or in OpenCV terms, pose.

After looking at the OpenCV tutorials, [Matthiew] found a demo that undistorts an image of a chess board. Using this same technique, he used fiducials from the ARTag project to correctly calibrate an image of his mechanical braille pins.

As for why [Matthiew] went through all the trouble to get a computer to read braille – something that doesn’t make a whole lot of sense if you think about it – he’s building a braille eBook reader, something that just screams awesome mechanical design. We’d be interested in seeing some more info on that project as well.