From: Neil <picdude3@narwani.org>
To: Microcontroller discussion list - Public. <piclist@mit.edu>
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Date: Fri, 18 Sep 2020 12:11:42 -0700
Subject: [EE] light sensor array?
Thread-Topic: [EE] light sensor array?
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I want to measure the position (height) of a laser line level (device=20
that projects a horizontal line of light).  2" of measurement would be=20
nice, 1" I'd say is minimum.

First thought is that I could use a light sensor array (such as in a=20
sheet scanner), but this is a one-off project, and I'm not up for=20
finding one that I can hack and then trying to reverse engineer it right=20
now.
The ones I'm finding on Digikey etc (which will have datasheets) are=20
low-cost enough ($10-$20), but either have a very short range (~0.5" or=20
less), or the longer ones are discontinued.
Any recommendations for one of these?  I don't need high resolution=20
(even 1mm is fine).

Yes, I could put the sensor on a linear servo, but then I'd have to=20
ensure that mechanism is tight and not introduce any noticeable errors=20
in the system.

Alternate option is to let the light hit a diffuser (like say parchment=20
paper) and use a camera on the other side to detect the height of the=20
light line.  I'd have to (finally) learn openCV perhaps, but that's prob=20
fine.

Still thinking of other ways to do this too, even perhaps a curved lens=20
or mirror to compress a couple inches of range down to fit one of the=20
available sensors.

Brainstormy thoughts appreciated.

Cheers,
-Neil.


--=20
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