it uses the "persistance of vision" of the eye
what they do is as the strip of led's move they turn them on and off in a
patern such that they make the word.

imagine a dot matrix printer

there is no real way you could make it work as a "walking past" type thing

google
http://www.google.com.au/search?hl=en&ie=UTF-8&q=led+%22persistence+of+visio
n%22&meta=


-----Original Message-----
From: pic microcontroller discussion list
[mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Lindy Mayfield
Sent: Sunday, May 23, 2004 7:48 PM
To: PICLIST@MITVMA.MIT.EDU
Subject: [PIC:] Single Row of LED's Illusion - How they do that?


Hi,  I was wondering if anyone knows about or knows of a resource that
explains the logic of how to get the illusion of text by using a single row
of LED's moving back and forth.

I'm not even sure how to describe this or what it's called, so I'm having
trouble finding information on the net.  I've seen this as a clock with
LED's on a stick that goes back and forth like the old wind-up metronomes.

To be more specific, I had the idea of seeing if it would work with just a
row of lights in one place and you have to move your head to read it.

Thanks for any help.
Lindy

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