An intuitive and compact device that helps the visually impaired learn braille.

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An intuitive and compact device that helps the visually impaired learn braille.

The Problem

Just like anyone, being educated and literate is essential to the well being of people who are visually impaired. Education gives the visually impaired the opportunity to thrive, contribute to society, and have a successful career. Literacy in the braille system is so crucial to the employment of the visually impaired that 80 percent of the visually impaired who are employed can read braille. 

However, in recent years, braille literacy rates have been on the decline. Today, less than 10 percent of the visually impaired children can read braille, whereas the number was about 50 percent in 1950. The consequences? Over 70 percent of visually impaired adults are unemployed.

One reason for this trend is the lack of access to a braille education. There are far fewer braille teachers in America compare to the number of visually impaired students.

According to the National Federation of the Blind, "There is a chronic shortage of teachers who are qualified to teach Braille. It was reported in 2003 that there were approximately 6,700 fulltime teachers of blind students serving approximately 93,600 students"

Another reason for this trend can be traced to the advancement and availability of personal audio players and text-to-speech technology, which eliminated the need for the visually impaired to understand braille in order to gather information. While audio gives students information, it doesn't teach them reading and writing skills, such as grammar, spelling, and composition, all of which are essential to literacy.

“Audio can give you information, but it can’t give you literacy,” said Chris Danielsen, a member of the National Federation of the Blind.
According to Jim Marks, a board member of the Association on Higher Education and Disability, "We stopped teaching our nation’s blind children how to read and write."

The solution

How it works

Knobo is a tool that takes advantage of audio technology to aid braille learning instead of harming it. With Knobo, visually impaired students can now practice braille at home with minimum supervision.

Knobo is compatible with JAWS, Voiceover (Mac), and Narrator (Windows). No device driver is needed to use Knobo. The user can start using Knobo immediately after connecting it to the computer using a standard USB cable and opening up any text editors.

The six black keys on the right side of Knobo resemble the six dot cell in the braille system. To check a letter, the user would simply press down all the dots present in that letter, and the user would receive immediate audio feedback on what that letter is.

The two silver keys are the special keys, and they each have a unique grove on them so that a person that is visually impaired can differentiate them from the black keys. They each have a long press output in addition to the short press.

The knob is used to navigate through and read out texts. It can be switch between 2 modes: scroll through one word at a time or one letter at a time. To switch mode, press down on the knob.

Knobo can also serve as a more portable and intuitive keyboard for visually impaired computer users.


Image result for Braille wood block

Knobo is inspired by a traditional braille teaching tool: The braille peg block. Using the braille peg block, a braille instructor will insert a different combination of pegs to teach different braille letters. In a sense, Knobo is the "smarter" version of this tool, modernized to combat the braille literacy crisis and help prepare braille students for the 21st century.

  • 2 × 0805 1uF Capacitors
  • 4 × 0805 100nF Capacitors
  • 1 × TQFP Atmega32u4
  • 1 × 3225 Crystals 16MHz ±10ppm
  • 2 × 0805 22pF Capacitors

View all 12 components

  • What's Next

    Gary Peng10/17/2019 at 23:09 0 comments

    I envisioned Knobo as an HID (human interface device) that will take full advantage of computer speech-to-text technology to aid braille education, rather than harming it. 

    After over a year of development, I've successfully created an HID that is compact, easy to use, and manufacturing ready.

    As you all probably know, Knobo is a finalist in the 2019 SuppleFrame Hackaday Prize. I hope that with the funds from winning the prize, I will be able to start mass producing this product to bring it to the hands of visually impaired learners around the globe.

  • Project Video

    Gary Peng10/01/2019 at 06:48 0 comments

    Shout out to my friend Tom Stiel for helping me make this video happen.

  • Manufacturing

    Gary Peng10/01/2019 at 06:41 0 comments

    While I may be a high schooler, I'm no stranger to bringing products from prototype to production, which is proven by the two successful Kickstarter campaigns I ran for my other products.

    For Knobo, the electronics will be manufactured overseas while the enclosure will be manufactured by a local 3D printing company.

    Here is the estimated cost for the production of one unit:

    Electrical components + 3D print material: ~$10

    PCB Assembly: A $25 machine setup fee (one-time fee for any amount of PCBs) + ~$5/PCB

    3D printing: ~3 hrs

    Hand Soldering (for key-switches and rotary encoder) and final assembly: 5-10 min


    There are currently no products on the market that takes advantage of computer text-to-speech technology to enable and encourage the visually impaired to learn braille independently. 

    However, a secondary feature of Knobo is that it acts as an alternative to the standard keyboard and traditional Braille writers. In that sense, according to the San Diego Braille Institute, Knobo is better than traditional Braille writer in that it's far more compact and lightweight, have an additional scrolling/reading knob, and above all, extremely intuitive. During my user testing at the Braille Institute, visually impaired people were able to start typing out sentences using Knobo right away, whereas they had to go through a steep learning curve before using a standard keyboard or a traditional Braille writer.

  • Feedback from the Braille Institute

    Gary Peng09/29/2019 at 20:04 0 comments

    Here are some of the feedback we got from Sharon, a visually impaired Braille instructor at the San Diego Braille Institute.

    What she likes about Knobo:

    • Much more compact and portable than traditional braille writers
    • Very simple and intuitive, she was able to start typing right away
    • Allows Braille students to get instant feedback on whether or not their braille letter is correct when they are doing homework or the Braille instructor is absent.

    Features she hopes we can implement:

    • Punctuations.
    • Numbers
    • Capitalize letters
    • Compatible with Braille embosser.

    The video interview with Sharon is coming soon.

  • Visiting the Braille Institute

    Gary Peng09/28/2019 at 16:53 0 comments

    Last week, we were able to visit the Braille Institute of San Diego to get some user feedback for this project. More info will be posted later.

  • Switching IDE

    Gary Peng09/22/2019 at 04:46 0 comments

    I've recently switch my IDE to Atom in combination with PlatformIO. I made the switch because how expandable and customizable Atom is.

  • Knobo is a Hackaday Prize Finalist!

    Gary Peng09/11/2019 at 04:01 1 comment

    Proud to announce that Knobo is one of the twenty finalist of the 2019 Hackaday Prize.

  • All Knobo Iterations

    Gary Peng08/25/2019 at 10:23 0 comments

    Knobo v1.0 (Made on 6/3/18)

    My first time designing and manufacturing a PCB. It was running on a Teensy 2.0 with Teensyduino firmware.

    Knobo v2.0 

    Knobo now uses SMT components and a Atmega32u4 microcontroller.

    The PCB of Knobo v2.0 didn't work due to some design flaws :( 

    It was also my first time doing SMD soldering, It took me 3 tries and 3 wasted chips before I managed to solder the Atmega32u4.

    Knobo v2.5

    Removed one of the keys to make the whole thing more compact.

  • Keycaps Update

    Gary Peng08/24/2019 at 06:15 0 comments

    Keycaps are now round to better represent the Braille cell, and the two "special" keys now have a grove to help the visually impaired to identify them.

  • Github Fixed

    Gary Peng08/20/2019 at 18:55 0 comments

    The Github repository should now be visible

View all 12 project logs

  • 1

    All the STL, Gerber, and BOM files can be downloaded from my Github.

    For the keys, use any Cherry-style mechanical key switch.

  • 2
    Placing the Main Components

    Place the Encoder onto the PCB

    Place the mechanical key switch through the 3D Printed case into the PCB below

  • 3

    Use the schematic on my Github as a reference when soldering.

    I chose to hand solder the PCB since I don't have the equipment for hot air soldering. If you also choose to solder the PCB by hand, be sure to use plenty of flux, a good pair of tweezers, and Kapton tape to hold down large SMD components.

    I used 3 soldering iron tips:

    • Pencil tip for THT parts
    • Conical tip for SMD parts
    • Hoof tip for drag soldering the Atmega32u4 (follow the video above if you've never drag soldered before)

View all 5 instructions

Enjoy this project?



kwapiszon wrote 10/13/2020 at 07:27 point

many blind person dont know how read braile code.

  Are you sure? yes | no

icewalker wrote 08/12/2019 at 14:54 point

Hello Gary,

May I ask you if you 'closed' the source of your projects, at least this one Knobo?

The link to the github page is broken, is that normal?

Nice project though...

  Are you sure? yes | no

Gary Peng wrote 08/27/2019 at 04:44 point

Sorry for the late reply, the link should be fixed now.

  Are you sure? yes | no

Vlad Conut wrote 08/12/2019 at 11:13 point

Looks pretty cool I always wanted something like this, might still the idea. Though I have to ask, USB mini-b ? 😁

  Are you sure? yes | no

Gary Peng wrote 08/27/2019 at 04:42 point

I choose USB mini-b because it's easier to solder by hand.

  Are you sure? yes | no

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