Introduction: MOLBED - Modular Low Cost Braille Electronic Display
The goal of this project is to create an electronic Braille system that is affordable and can make this technology available to everyone. After initial evaluation, it was clear that thus the design of the individual character had to meet some minimum requirements:
- must use as many parts that are already commercially available
- should be made up with the lowest parts count possible
- custom parts must be easy to prototype, easy to scale up (injection molding)
- power must be not needed to keep the state of the pins
After working on several iterations, I have designed an electronic Braille character with a magnetic retaining system that has a really low parts count, is easy to reproduce or to scale up for production!
The project was self-funded, and I decided to not patent this system because I'd like to see as many people as possible benefit from it.
How does it work?
With the current design, each "dot" on a character module is made up of 2 3D printed parts (Body and Magnet holder), 2 M2 nuts, 2 magnets, and 0.1mm enameled wire. A controlling PCB also hold the bodies. This design uses a really low parts count, and efforts have been put to use parts already available, such as the M2 steel nut; this design allows for a very low cost per character.
A (not definitive) cost analysis
The cost for a single pin , for a production in the order of hundreds, is estimated around or less then 0.85€. It includes nuts, 2 injection molded parts (magnet holder and body), magnets, and coil. The cost for a single character is thus in the order of 5/6€ per character, with a small/medium sized production. The cost for an entire line of 10 characters is around 120€, including 60€ of characters and 60€ of pcb, most of it due to the TB6612 currently used which are quite expensive. An hypothetical device with 8 lines, a controlling board, sensors, battery and enclosure should have a total cost of less than 1000€ for a medium/small production, allowing a final retail price of probably 2000€... which is quite not bad compared to the commercial products available today!
2 × M2 Steel Nut An M2 steel nut is used as an easy to get, low cost part for the holding mechanism
2 × 2mm dia, 2mm tall magnet They are inserted into the Magnet holder
1 × Magnet holder (3d printed) Magnet holder is available to download as STL file
1 × Body (3d printed) Body is available to download as STL file
1 × Coil (0.1mm enameled wire) 5.5m are used, approx 300 turns
Step 1: All the Files and Parts You Will Need!
This is the list of the provided files. Remember, everything here is WIP!
- PCB.zip (Braille v2 pcb Eagle files)
- BrailleSystemComplete.zip This is the concept of the Braille Tablet I am going to develop (should funding or winning some Big Prize happen!). Zip files contains the full Solidworks assembly. Requires Solidworks 2015.
BraillePrinterSystem.zip This is the project for the portable Braille Printer that I am designing. When completed, it should be integrated in the docking station of the Braille Tablet. Zip files contains the full Solidworks assembly. Requires Solidworks 2015.
BrailleChar3.zip This is the PCB for one character, Zip files already used for production of the PCB (Gerber, drills, etc).
Test_DemoBoard_Uno_Oled_FILMS.ino This is a sample Arduino program. It will show letters "F I L M S" as shown in the video. Requires an Arduino Uno Board and the "Arduino Shield with Oled" PCB.
ArduinoShieldWithOled.zip This is the latest version of the demo board for testing characters. It is designed as an Arduino shield for Arduino Uno. Zip files already used for production of the PCB (Gerber, drills, etc).
braille_newer_smallpads_widespace.sch This is the PCB for one character ( Eagle Schematics)
braille_newer_smallpads_widespace.brd This is the PCB for one character ( Eagle Board)
MagnetHolder_v8.STL Magnet holder for each pin. Can be 3D printed with a resin-based 3D printer. Design still work in progress, as is this project.
CorpoV8.STL Body for each pin. Can be 3D printed with a resin-based 3D printer. Design still work in progress, as is this project.
Step 2: Instructions
3D Printing the body and magnet holder The body and magnet holder file are available in STL file format and can be printed with a resin-based 3D Printer. Part thickness is down to 0.3mm in some points, but it still printable, and after UV curing the part is strong enough.
Assembling the magnet holder Once you have 3D printed the parts, it is necessary to assemble them. This video shows how the different components of one pin are assembled for the current prototype.
Coil winding I assembled a simple machine to automate the coil winding. It is controlled by an Arduino.
Assembling the CharacterPCB Once you have assembled the 6 pins, it is time to insert them into the characterPCB and solder them.
Step 3: Testing BrailleShield Demo Board
In order to be able to quickly test the Braille character units, I designed a demo board, that should be also useful to showcase the project to potential users. This board is designed as an Arduino shield, 12v powered, using 3 TB6612 ICs to drive the coils. It has a button to select the showing modes, and the space for a 128x64 Oled that will display the letter that corresponds to the Braille letter shown by the pins.
Eagle design files are available.
Step 4: Concepts for Braille Tablet With Docking Station and Printer
Both are available for download as Solidworks assembly. The printer is
quite refined and with some refining is ready for prototyping.Winning the Assistive prize or find a sponsor would be super! Up to now all the project was self-funded and it has been a quite time-consuming project, so some funding may be necessary for this project to be continued...
Step 5: MOLBED Tested and Lots of Feedback!
During a meeting with an association for blind people in Italy, MOLBED has been tested and we received a lot of feedback, that will be very important for developing a product that is tailored to their needs.
This is a short list of their suggestions / requirements:
- Multi line is not important as one might think;
- a standard size Braille cell dimension, on the other hand, is more desired to get faster read speed.
- The MOLBED character can be re-configured to take the same, or slightly longer space, but have the same pin size and distance as standard (expensive) Braille cells;
- Integrating a Braille paper printer on the docking station may be very interesting;
- Chances of funding for this kind of projects will probably be much difficult for the current "state of things", at least in this country, despite they recognize that this project really has a lot of potential. So at the moment this competition is still the best opportunity for this project to be continued and give this people a low cost alternative to expensive products, and that can be really tailored on their needs!
First Prize in the
Assistive Tech Contest