The
devices described below were engineering projects designed and built by the Research and Development
Branch at the Kentucky Office for the Blind. All technical information is being made available to any interested party.
Contact the Kentucky Office for the Blind, 800-321-6668, for more detailed technical information about any of these projects.
ZOOM MRT-3 Rhythm Trak Drum Machine Speech Interface , 2004 -
Designed and built by Wayne Thompson for a music producer who is blind, this device captures text from the Zoom unit's 4-character LED display in real time and sends it to a text-to-speech synthesizer board. The custom interface circuit that connects to the Zoom unit is shown on schematic page 1 and schematic page 2. This circuit runs custom firmware based on the BASICSTAMP2. The Zoom display can be set to speak automatically whenever it changes, or speak on demand by a manual pushbutton request. Four photos, 1, 2, 3, and 4 are avaiable as well as an abbreviated MRT-3 manual in MS Word and hyperlink format.
Split Headset Adapter
(2KB) - Simple combination of audio adapters to allow two separate audio sources
(such as computer speech and transcribing machine) to be routed to each separate
earpiece of a stereo headset.
Bar Talk (50KB) - 1994-1995 -
Conceived and designed by Wayne Thompson, this project was a talking bar code system. It included BarTalk software, a custom written talking database program
supporting bar code input. This project was published in the November
1995 issue of ID Systems magazine and was the forerunner to several commercial talking bar code devices for the blind that would appear in later years.
Kentucky
Light Probe - 1995 - Designed by Wayne Thompson, this is a handheld, pushbutton device that produces an audio tone
whose frequency corresponds to the intensity of the light it is pointed toward.
Many different light probe designs were in existence and this was just an improved version being small, light, sensitive, directional, easy to build, and inexpensive (about
$6 parts cost). A parts
list and schematic
is available. Printed circuit board is available from Kentucky Department
for the Blind. This project was published in the March 1996 issue of
Circuit Cellar Ink magazine and was later marketed by the National Federation of the Blind.
Braille Digital Clock/Calendar
(60KB) - 1994 - A clock with a 6 cell refreshable braille display that updates itself
automatically each second and displays hours, minutes, and seconds.
Various pushbuttons allow setting of time, date, am/pm, weekday, and alarm.
Total parts cost is about $500, most of which is the 6-cell braille display.
This project was published in the October 1994 issue of Circuit Cellar Ink
magazine. It was conceived and designed by Wayne Thompson in response to a need by a client of the Kentucky Department for the Blind working at a commercial radio station who needed a silent and "accurate to the second" timepiece. Due to the high cost and limited market, this project never became a commercial product. A schematic, assembly code source, assembly code listing, hex code listing can be downloaded.
LCD Interface (95KB) -
1993 - Originally designed by Wayne Thompson to make an electronic music device (Yamaha QY10) accessible to a blind user, this device can actually capture LCD (Liquid Crystal Display) text from various consumer products.
Over a dozen devices have been successfully accessed such as music keyboards, printers,
telephones, etc. (list included). Parts cost is about $116. Printed
circuit board and prepunched case panels available from KDFB. This project is now somewhat obsolete since the formerly ubiquitous LCD text display driver, Hitachi HD44780, is now rarely used and is instead being replaced by graphics type LCD displays. Download project technical files here.
Audio Tone Indexer (24KB)
- 1991 - This project was conceived and designed by Wayne Thompson to create an improved and low cost alternative to existing tone indexers on the market. This device was used by volunteer readers in the Ketucky Volunteer Recording Unit to mark page and chapter boundaries in recorded books by adding subsonic tones
during the recording process. Simple, reliable, and inexpensive (about $45
parts cost). Printed circuit board available from KDFB.
Walk 'n Talk Speech Synthesizer - 1990-1993 - Designed by Wayne Thompson, this project was originally used to create a talking vending machine for Crane/National Vending Company. It quickly became apparent that the device could also be used as a general purpose text-to-speech synthesizer for blind computer users. Based on the RC Systems V8600 speech synthesizer module, the Walk 'n Talk was packaged in such a way as to provide a low cost and versatile alternative to existing text-to-speech devices on the market. It's uniqueness was small size, battery powered, both RS-232 serial and parallel inputs, and low cost. In the 1990's, over a hundred units were built by the Department for the Blind for our own visually impaired clients. A commercial version, the LiteTalk, was marketed by MicroTalk for many years along with their DOS based screen access program, ASAP. Eventually, personal computer technology advanced to the point of creating speech in software and using the internal sound card present on every computer. This made the external text-to-speech synthesizers, like the Walk 'n Talk, virtually obsolete overnight. While our stock printed circuit boards designed for this project has been exhausted, the pcb layout is still available as are the schematic and parts list.
Tweedle Dump (5KB)
- 1986 - Conceived (and named!) by Tim Cranmer and designed by Wayne Thompson, this is a simple, transparent device that connects in series with any RS232 data connection
and produces a chirping sound ("tweedling") while data is moving
("dumping"). Alows a listener to know when data flow has stopped.
Kentucky PortaBraille and PocketBraille
(267KB), 1985-1988 - Now obsolete, these project files originally released in August
1985 are still available by clicking the above link. Both devices were conceived by Fred Gissoni and Wayne Thompson. The original
project was published in the February 1988 issue of QST Amateur Radio magazine. Prototypes designed and built by engineer Wayne Thompson later became commercial products marketed by Southland Manufacturing Company of Lexington, Kentucky. Later, an improved version of the PocketBraille was produced by the American Printing House, Louisville, Kentucky. The APH PocketBraille was quickly eclipsed by Blazie Engineering's Braille 'n Speak and Braille Lite,
greatly improved commercial versions of this original project. The Braille 'n Speak became the world's first widely distributed commercial portable notetaking device for the blind with over 20,000 units shipped worldwide.
Kentucky
Modified Perkins Brailler, 1981-1983
-- This was the first major project undertaken by the KDFB Technical Services
Unit. Conceived by the program's director Tim Cranmer and designed and built
by engineer Wayne Thompson, this project was a personal braille printer created
by automating the ubiquitous manual Perkins Brailler. While now obsolete,
this was one of the first personal braille printers available. It's direct
commercial successor, the Cranmer Modified Perkins Brailler by Maryland Computer
Services (later Blazie Engineering), sold over 1000 units. The Louisville
Telephone Pioneers Group also built about 30 units. Several hundred construction
manuals were requested and sent out worldwide. The assembly language source
code listing for the Intel 8035 microprocessor and the corresponding hex
code listing is still available by clicking these links. If you have a
"Kentucky Modified Perky" and need additional technical information
on the original project, contact the Kentucky Office for the Blind at 800-321-6668.
