, and copies for your friends – it’s that eye-opening).
After reading that book, I realized I wanted to do something directly. So, consulting with local blind people (including Graeme himself), I decided to start with a Braille Display.
Typically, if a blind person wanted tactile Braille from anything digital (computer display, website, etc.) it needed to be converted in to six individual ‘dots’ per character, using small pins that were raised or lowered so as to create the appropriate letter (or combination, which is the case with Grade 2 Braille). This three by two grid of dots is the Blind person’s character set:
However, Braille display devices run around $7000 – well out of range of most blind people. Yet with a device like this, doors open wide; for example, all the content of the Internet can be read in the comfort of your home; writing and interaction becomes much easier, and waiting for huge Braille volumes in the mail is a thing of the past.
Braille provides the most reliable communication medium for a Blind person to access the printed word, and therefore denying it (or making it so expensive as to effectively deny it) is an injustice. According to one study, 56% of those who read Braille were employed, versus 23% for those who could not. Obviously, lack of Braille instruction is significant. The fact is, for blind people, Braille is a right, not a privilege. And for that reason I designed a Braille Reader to bridge the gap:
This Refreshable Braille Display (called ‘Audrey’, after my mother) takes in computer data and displays it on a small window in the center. This prototype is only five characters; it’s a proof of concept to get the programming, alignment and so forth ironed out.
To understand how it works, consider a single Braille character of two columns of three dots each. Any of these six dots can be either raised, or not; computer programmers will likely catch on right away that means 2 to the power of 6, or 64, possible patterns are available. If we were to mold all 64 patterns onto a long stick, and then move the stick forwards and backwards so that the appropriate character showed through a tactile window, we’d have a simple mechanical Braille display.
Of course, there’s a problem – such a stick would need to be long – at about 1/2 inch per character height, you’d need a stick 32 inches long! Also, the time to move the stick back and forth with a motor would be very time consuming. So as a compromise, this device uses two sticks per character, one each for the left and right columns:
The result is that eight possible patterns per stick is enough to display all 64 possible Braille characters, in a smaller package, and with faster update speed.
From there, the design next requires a motor to move each stick. Of course, it’s not practical to use one motor for each stick or pin, so we use a single motor for all, with a second motor to move the first from pin to pin (much like a printer moves the active head across a piece of paper). This cutaway shows the mechanical parts in better details:
To finish off, the rest is straightforward: using the Open Source Arduino microcontroller running a monitor program, the Braille Display receives serial data from the computer, translates it into movement and position data, and then moves each rod or stick to the appropriate character position. A motor controller board, additional serial port, and assorted switches and wiring, is about all that is needed to complete the design.
The result is a low cost Braille display – in fact, I estimate a 40 character display can be made for under $200, significantly less than the multi-thousand dollar devices out there today. And while it won’t have all the features of the top of the line model, it will enable those who could never afford a Braille display to actually have one of their own.
In fact, the motivation behind my design has always been ultra-low cost; using two motors for instance, instead of multiple ones reduces the cost considerably. Also, the design is currently adapted for use with a laser cutter, which means that the parts could also be cut out of various materials with hand tools. And the hardware is minimal; with Arduino devices selling for $20-$30 dollars on eBay (and that of course is with sellers still making a profit), even someone in a third world country should have access to the components to build this device cheaply.
Additionally, my goal is to Open Source every part of this device. Open Source solves several problems; unlike proprietary knowledge, this is available to anyone to edit, change, and hopefully, improve. It means ideas can spread faster, with no proprietary ‘locks’ to restrict knowledge. It is immune to accidents; should I for any reason leave off the project, someone else can continue. And with more minds able to look at the issue, the chances for solutions becomes exponentially greater. As Linus Torvalds of Linux fame pithly observed, “Given enough eyeballs, all bugs are shallow”. Opening the hardware and software to this device ensures that problems are visible and are dispensed with quickly.
I do not consider this the ultimate answer to low-cost Braille display – far from it. It is a first small step. However. it’s 2011 – isn’t it time someone took a step forward? It is my hope that from this point on, others will take bigger and more confident steps, with the result that the true beneficiaries, those that are blind, obtain better and better products at lower and lower prices.
One day soon, I imagine a young child in rural India finally being able to take in all the text of the Internet through a Braille Display – if we can provide her with the opportunity, it’ll have been well worth it.
