[BRLTTY] Getting my braille driver for the FCHAD working.

[Dave Mielke]

[quoted lines by timothyhobbs at seznam.cz on 2012/10/19 at 00:09 +0200]

>Oh, I had never heard of the opticon.  But yes it is similar.  It's a pity,
>seems you can no longer buy those devices.  I wanted to get an idea of the
>price!  

They cost a few thousand dollars ech. Not veyr cheap.

The weakest part of an Optacon was the wire connecting the lens module to the 
base unit. It was thin and light weight, to mkae it relatively easy to put up 
with, but that thin cable contained 39 (I believe) wires. This meant that each 
of those 39 wires had to be very thin. My experience was that after about a 
year of constant use there'd be a breakage. In the end, it meant that I had to 
own two Optacons so that I'd have one to use while the other one was off having 
that connecting cable repaired.

Another problem with the Optacon was that it had a scan rate which didn't match 
the scan rate of a computer terminal or monitor, so, when used on one of those, 
the image on the pin array would flicker quite badly. Also, holding the camera 
up against a vertical screen would become rather tiring.

>When I was prototyping, I made my device work so that one used a
>stylus to select the character, rather than touching physical touch sensors.
>  This was not a good method.  I found when reading that the main trouble
>was in figuring out where the stylus was and not accidentally skipping
>letters.  

This is where a constantly moving image would've helped. When it jumps from 
character to character, I can well imagine how easy it'd be to lose track of 
precise position, or even misguess exact direction of motion.  When the image 
slides right along with the sensor, however, the user always knows exactly what 
he's doing and doesn't tend to lose his place. With the Optacon, for example, 
if the image of the character started to slowly move up then I knew I was 
moving the camera at a slight downward angle and could immediately make the 
needed correction.

>Of course I can program the device to scan across similarly to
>the opticon.  Take our sensor row as an example: 1 2 3 4 5 if the reader
>were to place only their index finger on the device, I could display for a
>touch registering only sensor 1, the entirety of the first character, for a
>touch registering 1 and 2 however, I could display the second half of the 
>first character and the first half of the second.  I don't think this would
>be a very good system though.  

No, it wouldn't. Since a braille character has only two columns, displaying the 
right half of the previous character along with the left half of the next 
character would simply look like yet another, entirely unexpected and odd, 
braille character. :-) Since the Optacon presented six columns of pins, the 
motion of the image felt quite smooth.

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Dave Mielke           | 2213 Fox Crescent | The Bible is the very Word of God.
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