On Tue, 14 Jul 2015 16:12:49 -0700, etpm wrote:

I bought today a "hands free" garbage can for the kitchen. It said on
the box that it has a motion detector for hands free operation. The unit
as a whole is well made and has features I like. The problem is that
when slid under the counter the motion detector detects the underside of
the counter and the lid opens and stays open. So it must detect
reflected IR, whether moving or not. The under counter position is where
it must go. The hands free opening is why I bought it, it is for use in
the kitchen. All the electronics are in the top, which comes off in
order to remove the garbage receptacle. So I need some sort of sheet IR
absorber so that the thing will work properly under the counter. I can
operate it manually but I don't want to touch the garbage can when I'm
cooking and have food of one sort or another stuck to my fingers.
Anybody have any ideas? I thought about maybe taking the thing apart and
putting a mirror inside that would make the sensor see at an angle so
that it wouldn't detect the underside of the countertop but then it
might open when someone walks past. So it looks like what I really is a
good IR absorbing material that I can fasten somehow to the countertop
underside. Any suggestions?

Try black cardboard. Most things that look black in visible light look
black in IR, too (not everything, but most).

If it mostly works but still false-alarms, fold the cardboard into a fan-
fold shape.

If that doesn't work, I'll give you a full refund of all charges for
writing this post.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com