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Thread: and [OT] Measuring weight using TSL214 with a PIC
picon face BY : Brent Brown email (remove spam text)


Haven't been watching this thread, but one way of measuring 0-
10mm distance you might consider is IR reflected intensity.

One LED, one photodide, a few discretes and maybe an OpAmp.
Pulse the LED on, AC couple and highpass the photodiode output
so as to reject 50/60Hz and sunlight, measure the intensity of the
received pulse with A/D input, turn the LED off. Intensity is
inversely proportional to the square of the distance. Use a lookup
table to work out the distance. Fairly simple, quick and straight
forward, low parts count, low average power consumption, no
moving parts, make the micro do the hard work.

Brent Brown
Electronic Design Solutions
16 English Street
Hamilton, New Zealand
Ph/fax: +64 7 849 0069
Mobile: 025 334 069
eMail:  spamBeGonebrent.brownspam_OUTspamKILLspamclear.net.nz

<200006070131.NAA29979@fep4-orange.clear.net.nz> 7BIT

In reply to: <E921592EB0BCD211880A0000F87B34C101E44B@nefexch3.newcastle.tafensw.edu.au>
See also: www.piclist.com/techref/microchip/devices.htm?key=pic
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