Alt-BEAM Archive

Message #04851



To: beam@corp.sgi.com
From: Steven Bolt sbolt@xs4all.nl
Date: Thu, 24 Jun 1999 19:37:49 +0200 (CEST)
Subject: [alt-beam] Re: PhotoDiodes


On Thu, 24 Jun 1999, Richard Piotter wrote:

> The chances of finding a photodiode or photo transistor in a walkman is
> almost nothing.

Actually, some of them have nice optical tape motion sensors:
IR LED and photodiode in a single, tiny package, looking at a disk
with four reflective sectors, resulting in eight rising and falling
edges per 360 degrees. You could use the whole shebang as a low
resolution shaft encoder, or as device to make your `bot a little
more conscious of whether it is moving or not (no pulses, no
motion).

Best,

Steve

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# sbolt@xs4all.nl # Steven Bolt # popular science monthly KIJK #
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