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.

Reduced-cost Braille display for use with computers

Apparently a Braille computer display can cost several thousand dollars. That’s why [David Pankhurst] is working on a low-cost alternative. His offering is an open source version he calls the Audrey Braille Display.

The concept is quite good. This prototype has one line of six Braille characters. Each character is made of two sliding strips containing eight arrangements of bumps. These can make up any character when positioned correctly. Two motors do all the work, one engages a single strip to reposition it, the other moves the first motor to select which strip should move. This is explained quite well in [David’s] most recent post. Or you can get a preview of the physical build here.

The concept is sound, but the refresh rate must be very slow. We wonder if there’s a way to keep one motor stationary and use solenoids to engage a drive shaft on the individual slide rods? This way, every row could be changed at the same time, disengaging when the appropriate slot is reached.

This hardware is much needed until developing Braille technologies actually come to market.

[via Dangerous Prototypes]

Hackaday Links: September 28, 2011

Disposable coffee maker

[Sepehr] didn’t have a coffee maker, and the local coffee shops were all out of joe. He got his fix by making a drip coffee maker out of disposable cups and knives.

Flexible braille display

Thin film technology is being developed to help the visually impaired. This flexible OLED display has embedded muscle cells which create a braille display. [Thanks Aaron]

Printable iPhone tripod mount

Looking to make those iPhone videos a little more stable, and the pictures a little less blurry? Try out this printable tripod mount that [Chris] came up with.

Arduino macro photos

Speaking of photographs, [Daniel] wrote in to share some macro pictures he took of an Arduino. They’re sure to be of interest to those readers who love everything Arduino.

Carpeting a mouse

Add a unique texture to your mouse by covering part of the body with fabric. The lower half of the mouse case above is covered in a carpet-like material [translated]. [Thanks Clicker]

Beat Boxxx and Speak to Me/Breathe

[Steve] is in the MFA Design and Technology program at parsons, and as part of his studies, has built a couple really interesting projects. First, the Beat boxxx, as seen in the video above, is an 80’s retro looking portable beat looper. You create and loop your beats at the time of playing using simple hand gestures. The look is great, for those who enjoy cardboard and magic marker, though we think some tonal variation and possibly a wider pitch variation would really make this fun.

His second project is Speak to Me/Breathe. This project was meant to be a commentary on security in our daily information. He is visually displaying the braille symbols to spell out his emails. If any person were to spend the effort, they could decipher his emails. The finish on this project is quite nice, you can see a video of the display after the break.

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