No, mount LEDs horizontally, move the interruptor vertically (probably
with a lever to amplify the mechanical movement).  Read the weight code
out parallel from the PTs.

On Mon, 30 Apr 2001, Eisermann, Phil [Ridg/CO] wrote:

> Good idea, except for the 1/4" of movement restriction. Might be tough to
> get all those LEDs in there. Unless you have a lever that amplifies the
> movement.
>
> What about having a magnet on your moveable arm, and reading the position of
> the magnet with a Hall Sensor? Nothing to wear out here, either. And you can
> get pretty good results with those things over short distances (think
> millimeters)
>
>
>
> -----Original Message-----
> From: O'Reilly John E NORC [mailto:OReillyJE@CORONA.NAVY.MIL]
> Sent: Monday, April 30, 2001 3:46 PM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: Re: [PIC]: Measuring weight
>
>
> I like #5.
>
> A variation on this idea could be to use a binary "barcode" made by having a
> clear piece of glass or plastic with clear and opaque areas.  Use LEDs on
> one side and phototransistors (or whatever) on the other side.  All clear =
> 0 - 1/4 lb, 00001 = 1/4 - 1/2 lb, etc.  You wouldn't be touching the
> barcode, so it wouldn't wear out.  Just watch out for the pie splattering
> apples all over it!
>
> Just a brainstorm.
>
> John
>
> -----Original Message-----
> From: Lawrence Lile [mailto:llile@TOASTMASTER.COM]
> Sent: Monday, April 30, 2001 12:24 PM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: [PIC]: Measuring weight
>
> <SNIP>
>
> 5.  Run a springy shorting bar across a series of fine-pitch silver plated
> tracks on a printed circuit board, and measure the position of the shorting
> bar by various methods.  (port input, shorting out a series of resistors,
> keypad-like array, etc. etc. )   So far I can't think of too many problems
> wioth this, except I suspect it might be expensive to implement and the
> tracks might wear out.
>
> Any other ideas?
>
> -- Lawrence Lile
>
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