Most of them use a SPI communication. Which is just serial. The trouble is
the power. Most take 200 volts. I know that sounds like a lot but you just
need an inverter circuit to take what ever DC most of them use 12 volt dc from
their lipo batteries and convert it to 200 to activate the pins. So you need
two things. First you need the protocol the driver board uses. Then you need
the power circuit to power up the cells. The problem with just getting a few
cells is you will need the driver board from the manufacturer to support the
amount of pins. Most are set to use the amount that are in the display. You
could maybe take one apart and find out if you could read the protocol by using
a o-scope as you press keys. That is quite a bit of work though. First thing
is first you need to find the cells then we can see if we can find some docs
from KGS, Meteck, Orbit, Vispero, Humanware or who ever else you find cells
from.
I did this an easier way. I use my orbit Reader 20 and a serial cable. I
signed an NDA with Orbit and got their protocol. So I have things like a
brailling seven segment display and I am working on a Sphero RVR that will work
like turtle graphics but the input and output will be braille and speech
because the RVR is big enough to have the Orbit Reader 20 a Raspberry PI and a
small speaker all on top. I didn't remove the braille cells I am just using
the protocol of the display and powering it all by the rover body.
Ken
Ken
-----Original Message-----
From: raspberry-vi-bounce@xxxxxxxxxxxxx <raspberry-vi-bounce@xxxxxxxxxxxxx> On
Behalf Of Pranav Lal
Sent: Friday, January 1, 2021 5:47 AM
To: raspberry-vi@xxxxxxxxxxxxx
Subject: [raspberry-vi] Re: Can I build my own Braille display that is driven
by the pi?
Hi Ken,
I have access to a maker space so can get some help. How do I control the pins?
Is it like driving motors with an HBridge?
Pranav-----Original Message-----
From: raspberry-vi-bounce@xxxxxxxxxxxxx <raspberry-vi-bounce@xxxxxxxxxxxxx> On
Behalf Of kperry@xxxxxxxxxxxxx
Sent: Friday, January 1, 2021 11:06 AM
To: raspberry-vi@xxxxxxxxxxxxx
Subject: [raspberry-vi] Re: Can I build my own Braille display that is driven
by the pi?
Here is the part from one of the braille sells that I have been playing with.
This was similar to the bp18 kgs cells.
"circuit is powered up by a 12V DC adapter. A DC-to-DC
converter is used to convert the 12V input voltage to 200V
output voltage that is used to activate the piezoelectric "
So you would have to build a circuit to do that or buy one either way you would
have to know how to connect everything up for the power. Controlling the pins
is simple though.
Ken
-----Original Message-----
From: raspberry-vi-bounce@xxxxxxxxxxxxx <raspberry-vi-bounce@xxxxxxxxxxxxx> On
Behalf Of Pranav Lal
Sent: Thursday, December 31, 2020 11:20 PM
To: raspberry-vi@xxxxxxxxxxxxx
Subject: [raspberry-vi] Re: Can I build my own Braille display that is driven
by the pi?
Hi Ken,
Many thanks. Can't the pi do the processing and drive the cells instead of
having a dedicated board?
Pranav
===========================================================
The raspberry-vi mailing list
Archives: //www.freelists.org/archives/raspberry-vi
Administrative contact: <mike.ray@xxxxxxxxxxxxxx>
-----------------------------------------------------------
Raspberry Pi and the Raspberry Pi logo are trademarks of the Raspberry Pi
Foundation.
This list is not affiliated to the Raspberry Pi Foundation and the views and
attitudes expressed by the subscribers to this list do not reflect those of the
Foundation.
Mike Ray, list creator, January 2013
===========================================================
The raspberry-vi mailing list
Archives: //www.freelists.org/archives/raspberry-vi
Administrative contact: <mike.ray@xxxxxxxxxxxxxx>
-----------------------------------------------------------
Raspberry Pi and the Raspberry Pi logo are trademarks of the Raspberry Pi
Foundation.
This list is not affiliated to the Raspberry Pi Foundation and the views and
attitudes expressed by the subscribers to this list do not reflect those of the
Foundation.
Mike Ray, list creator, January 2013
===========================================================
The raspberry-vi mailing list
Archives: //www.freelists.org/archives/raspberry-vi
Administrative contact: <mike.ray@xxxxxxxxxxxxxx>
-----------------------------------------------------------
Raspberry Pi and the Raspberry Pi logo are trademarks of the Raspberry Pi
Foundation.
This list is not affiliated to the Raspberry Pi Foundation and the views and
attitudes expressed by the subscribers to this list do not reflect those of the
Foundation.
Mike Ray, list creator, January 2013
===========================================================
The raspberry-vi mailing list
Archives: //www.freelists.org/archives/raspberry-vi
Administrative contact: <mike.ray@xxxxxxxxxxxxxx>
-----------------------------------------------------------
Raspberry Pi and the Raspberry Pi logo are trademarks of the Raspberry Pi
Foundation.
This list is not affiliated to the Raspberry Pi Foundation and the views and
attitudes expressed by the subscribers to this list do not reflect those of the
Foundation.
Mike Ray, list creator, January 2013
