Accessible equipment such as oscilloscopes is probably off-topic for the
Blind Programming mailing list. But maybe not quite. ...
In 1968-69, my senior year studying electronics engineering at Iowa State
University, a graduate student built for me a box containing two
multivibrator circuits and threshold logic which would send the output of
one, the other, or both, to an earphone. The input to this device came
from two photo-transistors which were mounted at the ends of probes I could
put over my fingers. I would hear square waves when one probe or the other
was over lighted portions of the CRT oscilloscope screen. It was hoped
that by moving two fingers independently over the same waveform, I could
get a better idea of the waveform shape.
There were several problems. The most notable is that oscilloscope
waveform displays are seldom stationary. Even if you were looking at the
output of a function generator processed by a circuit, you at that time had
to adjust the scope's controls to achieve sync.
Around 1981, I saw a prototype accessible oscilloscope developed by Bill
Gerrey, Tom Fowles and others at the Smith-Kettlewell Institute in San
Fransisco, www.ski.org. If you could get a waveform to be stationary, you
could adjust a potentiometer which tracked the X axis, and a variable-pitch
tone represented the Y axis. At any point, you could send the Y voltage
reading out to a TSI Speech Plus board for a true digital readout. I don't
think many of those units were ever built.
And now for the programming: Although people use scopes all the time, they
also use various pieces of data acquisition hardware to digitize and
capture the output of circuits. I think that besides working with lab
partners on many of your experiments, you should find out what people are
doing at your institute with data acquisition hardware and software. It is
not trivial, but it is possible to analyze and reformat signals in many
ways, some of which could come close to real-time. You could also use some
piece of data and run it through the vOICe, found at
www.seeingwithsound.com
which converts graphical information into complex sound patterns. But a
talking description of a waveform is not on the radar, I'm afraid. It is
also sometimes useful to listen to electronic signals with an audio
amplifier or a radio, in order to detect changes in some parameter of
interest.
I don't want to discourage you at all. I only want to suggest that there
numerous ways to skin this cat, and you're going to need to act like a
student and go into problem-solving mode.
At 06:13 AM 3/14/02 -0600, you wrote:
>
>----- Original Message -----
>From: Michael Berry
>To: real-eyes@topica.com
>Sent: Thursday, March 14, 2002 4:48 AM
>Subject: Accessible equipment
>
>
>Hi list,
>I have run into a bit of a problem here with finding accessible equipment
for college. For two of my computer classes at devry this semester I need
to use ohm meters and oscilloscopes. Finding a ohm meter that talks to me
to give me my reading is not a problem, they are quite common. What I don't
know is where I can find an oscilloscope the will give me speech output of
my reading. If anybody has experience with this piece of equipment and
knows where I can get one I'll give you a hundred dollars just for the
information. If they do not make these accessible, can I have one made, and
if so, where? Any and all help will be appreciated.
>
>Thanks,
>Mike
>
Braille is the solution to the digital divide.
Lloyd Rasmussen, Senior Staff Engineer
National Library Service f/t Blind and Physically Handicapped
Library of Congress (202) 707-0535 <lras@loc.gov>
<http://www.loc.gov/nls>
HOME: <lras@sprynet.com> <http://lras.home.sprynet.com>
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