Our recent coverage of a Raspberry Pi Zero inside the official Pi keyboard prompted a reader to point us to another far more unusual keyboard with a Pi Zero inside it. It may be a couple of years old, but [Mario Lang]’s Braille keyboard and display with built-in Pi is still an interesting project and one that should give sighted readers who have not encountered a Braille display an introduction to the technology.
The model in question is a Handy Tech Active Star 40, which seems to have been designed to have a laptop sit on top of it. A laptop was not the limit of its capabilities, because it also has a compartment with a handy USB connector that was intended to take a smartphone and thus makes a perfect receptacle for a Pi Zero. Sadly the larger boards are a little tall with their connectors.
If this hack were preformed today he would undoubtedly have used a Pi Zero W, but since the Zero he had did not possess WiFi he relied upon a Bluetooth dongle for connectivity to the outside world. The BRLTTY screen reader provides a Braille interface to the Linux console, resulting in an all-in-one Braille computer in a very compact form factor.
This is one portable Braille computer, but it’s by no means the only one we’ve seen. Thanks [Simon Kainz] for the tip, and here’s a nod to the Pi keyboard that inspired him.
[jg] recently passed some damaged Braille signs and took on the challenge of repairing them. Informed by his recent work on PCB lapel pins, [jg] immediately thought of using circuit boards for this project. He’d noticed that round solder pads made for uniform hills of solder, and this reminded him of the bumps in Braille.
He began by reading up on the standards of the Braille Authority of North America, which stipulates a dot height of 0.6mm. He loaded up the PharmaBraille font system and laid it out the dots in photoshop, then and imported it into KiCad and laid out the boards. When the PCBs had arrived from OSH Park, [jg] soldering up the pads (lead free, but of course) to see if he could get the hills to 0.6mm. He’s experimenting with different methods of melting the solder to try to get more even results.
Braille interfaces crop up a surprising amount in hacker projects. This refreshable Braille display and keyboard and the Braigo LEGO Braille printer are prime examples.
Braille is a tactile system of communication, used the world over by those with vision impairment. Like any form of language or writing, it can be difficult to teach and learn. To help solve this, [memoriesforbecca] has developed Becdot as a teaching tool to help children learn Braille.
The device is built around four Braille cells, which were custom-designed for the project. The key was to create a device which could recreate tactile Braille characters at low cost, to enable the device to be cheap enough to be used a children’s toy. The Braille cells are combined with an NFC tag reader. Small objects are given NFC tags which are programmed into the Becdot. When the object is placed onto the reader, the Braille cells spell out the name of the object. Objects can be tagged and the system programmed with a smartphone, so new objects can be added by the end user.
It’s a great way to teach Braille, and an impressive build that keeps costs down low. Details are a little thin on the ground, and we’d love to see more detail on how the actuators on the Braille cells work. We’ve seen similar projects before, like this Hackaday prize entry. Share your theories in the comments below.
Electromechanical braille displays, where little pins pop up or drop down to represent various characters, can cost upwards of a thousand dollars. That’s where the Modular Low-cost Braille Electro Display, aka MOLBED, steps up. The project’s creator, [Madaeon] aims to create a DIY-friendly, 3D-printable, and simple braille system. He’s working on a single character’s display, with the idea it could be expanded to cover a whole row or even offer multiple rows.
[Madeon]’s design involves using Flexinol actuator wire to control whether a pin sticks or not. He designed a “rocker” system consisting of a series of 6 pins that form the Braille display. Each pin is actuated by two Flexinol wires, one with current applied to it and one without, popping the pin up about a millimeter. Swap polarity and the pin pops down to be flush with the surface.
This project is actually [Madeon]’s second revision of the MOLBED system. The first version, an entry to the Hackaday Prize last year, used very small solenoids with two very small magnets at either end of the pole to hold the pin in place. The new system, while slightly more complex mechanically, should be easier to produce in a low-cost version, and has a much higher chance of bringing this technology to people who need it. It’s a great project, and a great entry to the Hackaday Prize.
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.
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]