Friend I tried to download your pieces but they are in inventor format I don't have it because inventor asks for a lot of ram and in stl there are not all the pieces, you could put it in a compatible format like 3ds dae obj dwg dxf fbx fcstd ifc iv json kmz skb stl wrl xsi

It's amazing how expensive assistive technology is. A small flagil braille display costs more than $ 1,200 USD and a good quality one goes from $ 3,000 to $ 6,000. That is why I am developing an open source project. This is by no means a finished product. Being an open source project, I hope others will improve the design. In the near future, with the help of volunteers, Brailletouch will reduce the cost of a braille display by 90% and allow anyone who is visually impaired or deafblind to read and write braille, as well as use a computer or mobile device efficiently. and without noise. So if you know someone, if you are a creator, if you are curious or if you want to help, feel free to enter our repository https://github.com/brailletouch/Brailletouch and help me build a community around Brailletouch.
The encoder is practically the heart of the braille display. Most commercial braille displays have 40 or 80 braille cells. Since the most expensive on a braille display is braille cells, which cost more than $ 35 each, we are designing a new form of braille display with 40 virtual cells and a single physical braille cell, reducing most of the cost. . We are talking about a braille cell that can be made from 3D printed parts, I designed a different system. Instead of activating 40 cells at the same time and applying all the power to 40 physical cells, Brailletouch uses a physical encoder and a virtual braille display of 40 touch sensors placed in a matrix. In this way, the braille text is gradually displayed in a single braille cell as the virtual cells are touched. Parts can be easily printed.

My braille display design succeeds in reducing the cost of a braille display by over 90%. Currently, a braille screen has a cost between $ 1200 and $ 6000, being $ 1200 the smallest and most fragile, my proposal seeks to achieve a braille screen that can be manufactured between 100 and $ 150, it could even be much cheaper when making production mass. Basically, we could have a screen at an affordable price for all visually impaired and deafblind people.

My project is open source. The idea is to make available to anyone anywhere in the world a code that can be modified and improved, files for 3D printers to print their parts and an assembly manual, so that anyone can download, print, assemble and use

Its development is based on an esp32 microcontroller. (What is open source hardware)

I do this because I am looking for support if you can support or meet someone who can support with the following needs:

Microcontroller Programmer

Diceño in 3d

Handling the HiD protocol (we need to create the code for the Esp-32 to communicate with the breille HID)

Language translator

Documentation development

Economical support

Any company or organization that finances the project.

If you can support some of these needs or know someone who can do it or an organization that can financially finance the project, I would be very grateful if you could contact me at +584129994784

OUR REPOSITORY

https://hackaday.io/project/182904-project-low-cost-braille-display
https://github.com/brailletouch/brailletouch

With all those motors, driving them is a real issue, especially if the whole thing needs to be compact.

How much voltage and current do these motors need?

They may be small enough to directly controll the windings to the outputs of a uC or HC595 shift register.

That would be 2 motors on the 8 outputs of a 74HC595 Maybe these motors are available in different current / voltage combinations.

Maybe put 2 outputs in parallel to lower output resistance.

If the motors do not have to be driven you can put the outputs in Tri-state.

Another way to drive bipolar motors is to directly connect one side of each motor winding directly to GND, and the other to either a positive or negative voltage.

The two techniques can also be combined. Then you will need 2 switchable voltaga rails that can be either switched to GND or Vcc, and you connect these to one side of all the A and B coils of all the motors. Then switch the other side of those motor windings individually with the outputs of your shift registers. There are SOIC ic's with mosfet's in Half H-bridge configuration. They can be used to increase the current handling of the shift register outputs if needed. But just 2 transistors per output also work.

hi I’m working with a group on a project to improve the blinds way of life and I believe if we could mass produce the final product these could be put in stores and various other places so the blind don’t have to rely on others or rely on product placement 

Great project! Eepecially for blind people. Really kind of you.

I'm a student in china and want also start a project like this to help more blind people .Now I bought the vibraiton motor you have showed <a href="https://www.vibrationmotors.com/product-catalogue/cylinder-coreless-vibrating-motors/small-vibrating-motors-bl4i2j6-x10e/</a> . Is this vibraiton motor workable

hi vijay, may i ask where did u buy the small linear servo?  as shown in the new actuation system post?

https://www.aliexpress.com/item/DC-5V-Sankyo-2-Phase-4-Wire-Slide-Screw-Stepper-Motor-Micro-Stepper-Motor/32462050546.html?spm=2114.search0302.3.65.v5sqyj&ws_ab_test=searchweb0_0,searchweb201602_0_10051_10050_10053_10052_10338_10339_10055_10099_10175_10054...

Hello vijay, Im a student in University, I have a big interest in engineering and Im very excited about your project, Im wanna make one to present my grandpa on his birthday as a gift because he's blind. In your CAD files, it doesn't have an exact size, can you tell me the size of those things ?  Im looking forward to hearing from you, thank you so much .

Hi, it very gratifying to hear that, and is something that will motivate me to finish this project.

Were you able to open the files? do you want me to save the assembly as a consolidated step file?

I opened the file, but Im didn't see any size, maybe the size is integrated and when I bring it to the 3D printing, the printer will understand, right? If I can, I would like to see the assembly as a consolidated step file too, it would be very nice. I'm working on the program, it's almost done 

How about a tiny one of these? 

http://woodgears.ca/counter/

That one is pretty big, but shows the principle of operation.  Tape recorders had small ones.

Imagine 3 reels, mounted vertically, not horizontally like the counter.  Each reel is a square, so it has four positions, not ten.  On the facets of the reel is zero, one, one, or two dots.  So different combinations of the three reels can make a Braille character cell.

Turning the first reel once makes the next reel turn by one quarter.  Turning the second reel once makes the third wheel turn by one quarter.  Thus, the character can be reset within 16 turns.

The first reel can be driven by a direct drive motor, or a stepper, or a solenoid.  Only one drive is required for the whole cell.

I was thinking along the same line as those music box player drum, but the actuators are stretched to linear strips and driven by the new linear stepper motor. Sort of like paper tapes for old computers except with bumps.

The top part would be like this https://hackaday.com/2016/06/27/pinjig-soldering-clamp-has-pins-seized-by-airport-security/

Someone send me this link just yesterday, did you check the log involving pogo pins?.

 The stepper motors will be cleared from customs today, and I will CAD and post the design online as soon as it reaches here, possubly will give people more ideas. 

I love this idea. Id like to explore it after the current design is done. Possibly a micro gear train done on a SLA/PolyJet machine for a size acceptable for braille. 

hey... how about making the dots simple contacts that pass high voltage instead of fisically moving? Avoid any mechanism pattent.

Obviously high voltage enough to feel but not to harm or be unconfortable.... this could be ajusted by the final user as a preference. I dont know what is the threshold for this to work.

Your design basically becomes a PCB with exposed pads and a "High voltage" segment diver of sorts....

I had the opportunity to talk to someone in the field of psychophysics, the study of the relations between physical stimuli and mental phenomena on the subject of braille.  This approach is definitely one worth researching on, there are some very fascinating research in this field from Disney. Ill look more into it. 

This is probably the best project here.

Keep it up.

This is probably the best project here.

Keep it up.

Thank you for the encouragement!

Awesome project! Keep up the great work!

Thank you! 

Vijay, as K.C. Lee says, making a one off for study is ok.  It becomes a problem when multiple people start wanting to produce the same not knowing a patent exists.  Also, pls check Bristol Braille Technology's -   Ed Rogers   ---Quixote and Canute regarding the linear cams.    

Vijay,  

from the pat office rules I have been provided ... "Further , Section 146(2) of the Act and Rule  131(2) of The Patent Rules 2003 provide that every patentee and patent licensee should furnish the details of working of the patented invention in Form 27 in respect of every calendar year within three months of the end of each year"

I have no wish to enter into all the legalities with the patent office prematurely regarding whom I give permission to produce the device. It also makes it difficult to explain to potential manufacturers / licensees that permission has already been given to x, y, z.  

Guys like you would, I am sure, be able to come up with something  unique that can be developed in the public domain if desired.  The only criteria is that you would still need to do a prior patent search.

There are two separate issues.  One is a patent which describe the methods/ideas only valid in the jurisdiction(s) that has been granted/recognized.  The other one is the Copyright of the design.  i.e. actual artwork, design files etc. The project can retains its copyright regardless of the patent issues. The only thing is that the readers need to be informed of an existing patent which might affect if/where it can be manufactured/distributed.

Patents do allow for making a personal copy for studying purposes.  Sadly that this project get caught up in a patent dispute.

Disclaimer: I am not a lawyer.

I think it's an excellent opportunity for everyone to see for themselves and learn why so many improvements and inventions, sometimes life-saving and life-changing for the people in need of them, never see the light of day. It's because of patent squatters who "have no wish to enter into all the legalities", but had no problem with the legalities involved in registering their patent.

Hi Vijay,

while I have
been supportive and impressed with your efforts in trying to produce a rapidly
prototyped Refreshable Braille Display thus far, I was just informed by my patent attorneys that that I needto let you know that before you take this Refreshable Braille Display projectforward further you must be made aware that all of the features you havepublished thus far are covered under a patent application filed at The PatentOffice, Chennai, by myself on 05Nov2014 …5559/CHE/2014 . The said patentapplication for a Refreshable Braille Display covers the use of micro-motoractuated pins, the pin cantilever design, the mechanical stop to limit rotorrotation, motors with rotors or cams, mounted vertically or horizontally usedto lift pins directly or via an interposer, low force selector etc.  Iprototyped just one of the variants covered by the patent that I deemed to bethe most feasible and cost effective. Amongst the peoplefollowing your project on this open forum there might be some who believe that
this design is open source,  and that
prior arts and patents do not exist. I was advised that this impression needs
to be corrected immediately.

You will need
to let the public know that if anyone wants to exploit features of this design,
they would need to get in touch with me or my patent attorneys (Origiin IP Solutions LLP), as rules require that
even the Patent Office be kept informed of activities in regards to patents.

Hi Paul,

Sure no problem, I shall post a log relaying the same. Since the patent is already granted, would you be willing to put it under a non-commercial licence, so that people like me can develop the idea further?  and in case anyone wants to commercially use the design they may contact you. 

So far the CAD files i've released ( available in the dropbox link) are under the CERN licence (http://www.ohwr.org/projects/cernohl/wiki) let me know how best to modify it. 

I'm not sure Indian patents are valid on the Internet ;-)

You might have funding for ordering enough of those smaller motors now, it seems! Cheers!

I went to town buying all sorts of miniature motors from China, I just hope I made the right choices :p

This is very interesting and I commend you for your efforts.  Have you considered the possibility of using a rotary display?  Since each horizontal row of the Braille character only has four possible positions (no pips raised, left pip, right pip, both pips), any symbol could be conveyed using three cylinders with four faces each.  Two symbols side by side could be accomplished with 16-faced cylinders.  I understand that this would require some positioning feedback, but might be accomplished with cheap optical/mechanical encoding.  It may be a way to lower the total number of motors used and thereby reduce the cost and noise.

Mind you, this is simply off the top of my head idea.  Clearly you've been working hard at this for some time and are doing a great job.  Keep up the good work!

Hey!

Thats a good idea, another person had suggested something similar. Check my latest log, Ive bought miniature stepper motors that may take care of the positioning. 

Great project! :)

Thankyou! :D

Brilliant work!  

Thankyou! :D

Have you considered driving the pin pair positions with a set of 3 8-position cams using a single servo/motor and reduction gearing?

Thanks for the message and drawing! it got my mind wandering

I did a little research to see what gears can be used with pico motors :  http://www.didel.com/microkit/pricelist/

I don't think any of the off the shelf servo motors available would fit the size limitations. Do you know of any?

I like the idea of a single cam-train actuating multiple pins. 

check http://www.ebay.in/itm/322010918960?aff_source=Sok-Goog

combining this with a linear cam that has all the combinations of crests and troughs for a number of pins.

Have you considered shape memory alloys? they take more current than motors, but you could make some truly tiny actuators.

There is research regarding this (http://assistech.iitd.ernet.in/asme-15-rbd.pdf)

but has some apparent drawbacks: the refresh rate, heat produced and thus requires a cooling system current consumption, and fatigue.

If you know of any new developments in this field, do let me know!

Looking at the pin arrangement and the suggestion of using coils and magnetized pins made me think of another technology:  core memory.  Instead of a coil for each pin, wind rectangular coils so that you have three coils going across the [4] pins of two letters, and four coils, one for each  column of [3] pins.  drive an x-y pair of coils at the same time in the same 'direction, and only one pin would have the combined magnetic field to move up or down.  this lets you use 7 push-pull drivers  for the coils instead of 12.

I've been learning so much from people on hack a day, thankyou! I didn't know of core-memory until today! (https://en.wikipedia.org/wiki/Magnetic-core_memory)

This got me thinking of the electro-permanent magnets being used in google's project ara phone.  Electric potential will only we required to change the state.

I am thinking something like power inductors.  e.g.  http://www.coilcraft.com/me3220.cfm

3.2mm diameter.  Use these tiny disc shaped rare earth magnets from China. 

e.g. http://www.banggood.com/search/magnets.html

The inductor is on a ferrite core, so there will be some attractive force.  You can reduce the force a bit by having some minimum separation between the magnet and the coil.  You'll only need to apply current in one direction to repel it. 

Only issue is how much current and if the current is within Irms rating for heating.  If the current is small enough, there are SPI low side drivers with onchip protection etc.  Just have to google for "spi low side peripheral driver chip"

You sir, are a genius! Using off the shelf power inductors is a brilliant idea, and keep the cost low, and makes assembly/reproducibility easy.

 I've been thinking how to wind the coils myself. I shall give this a try and let you know how it goes!

I did a quick attempt at trying this, I got a ~3-4mm diameter indutor+core and a 10mm dia rare earth magnet. used 5V at ~ 1 A to power the eliminator. 

The attraction between the magnet and the ferrite core was more than the repulsion caused by the turning on of the coil. 

Maybe one with a smaller core would work better? you think its a good idea to keep persuing this and try a few more times?

I don't know the right answer to this.  The only thing I suggested is to have a minimum separation distance - put a cardboard shim between the inductor and magnet to weaken the force a bit.  There are also air core inductors for RF, but they are not designed for high currents.  Beyond that, it might need a lot more turns of coils than such types of cores.

In the old dot matrix printer, they have solenoids spread around the pin head and use pieces of steel wire to redirect the force.  The wires also do the printing.  It is a hell of a mess to fix the head - I keep mine alive by fixing it every few months for a while until I gave up.

"You sir, are a genius!" He always surprises me so that must be why :-)

K.C.'s electromagnetic core proposal sounds very interesting to me.

The modified cam is a nice trick but it does not fully exploit the electromechanical properties of the tiny motor. These 3mm or 4mm motors are designed for high speed, not torque, so they will heat a lot with pretty small torque, and I suppose they would need mechanical amplification with gears (micro-planetaries ?)

OTOH Lee's proposal reuses existing power coils (cheap !) with a very well understood and simple electromagnetic circuit. It's easy to control 1A currents (or more), the voltage does not need to be high so the actual power is a few Watts during a fraction of second.

What is also missing frmo the overall design, IMHO, is position sensors. A couple of wires should indicate that the moving part has reached one end or the other, so the driving current can stop, and a safety mechanism is triggered if it stays "inbetween" after a reasonable time (indicating electric or mechanical fault). Or even if the current is too high.

Good luck, I have doubt about the micromotors with simple cams, but I hope you will prove me wrong or find a better system.

@K.C. Lee I know what you are talking about, with the dot matrix head. My first prototype when I started attempting refreshable braille used it. 

It would heat up too much, and would scare the blind when I tried user testing, because of the heat of sound.

I'll keep trying with different inductors, lets see what works.

@Yann Guidon / YGDES The position sensor is a good idea and will be needed thanks!

Check out the latest log, the cam thingy look like it might work, I was skeptical myself!