GP2D02 problems in sunlight...
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Photographic films, exposed or not, does not have an emulsion that is
somowhat "frosted", that will difuse light decreasing the range of
sensor ? Try see what happens with a laser beam passing thru a film.
ACJacques
Rodent wrote:
>
> A piece of exposed, developed color film should work.
>
>
Original Message
>
> > >I am having trouble getting reliable results from the GP2D02 sensors
> > >in sunlight. The cases have been grounded. Everything is fine
> > >indoors. Outdoors, the noise floor goes way up. I get frequent
> > >readings of 100 or more units (differs from sensor to sensor, worst
> > >not necessarily the one pointed closet to sun), and short-time
> > >averaging does not help too much.
> >
> > Start with a filter in front of the GP2D02 to filter out all but the
> > wavelength you want to receive.
>
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somowhat "frosted", that will difuse light decreasing the range of
sensor ? Try see what happens with a laser beam passing thru a film.
ACJacques
Rodent wrote:
>
> A piece of exposed, developed color film should work.
>
>
Original Message
>
> > >I am having trouble getting reliable results from the GP2D02 sensors
> > >in sunlight. The cases have been grounded. Everything is fine
> > >indoors. Outdoors, the noise floor goes way up. I get frequent
> > >readings of 100 or more units (differs from sensor to sensor, worst
> > >not necessarily the one pointed closet to sun), and short-time
> > >averaging does not help too much.
> >
> > Start with a filter in front of the GP2D02 to filter out all but the
> > wavelength you want to receive.
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and Body
of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Comments
in sunlight. The cases have been grounded. Everything is fine
indoors. Outdoors, the noise floor goes way up. I get frequent
readings of 100 or more units (differs from sensor to sensor, worst
not necessarily the one pointed closet to sun), and short-time
averaging does not help too much.
Any advice?
Thanks,
Mike
>I am having trouble getting reliable results from the GP2D02 sensors
>in sunlight. The cases have been grounded. Everything is fine
>indoors. Outdoors, the noise floor goes way up. I get frequent
>readings of 100 or more units (differs from sensor to sensor, worst
>not necessarily the one pointed closet to sun), and short-time
>averaging does not help too much.
Start with a filter in front of the GP2D02 to filter out all but the
wavelength you want to receive.
Jim H
Any ideas on where one could acquire such a filter?
Thanks,
Mike
--- In basicstamps@y..., Jim Higgins <HigginsJ@s...> wrote:
> At 14:51 07/23/01, pdop@y... wrote:
>
> >I am having trouble getting reliable results from the GP2D02
sensors
> >in sunlight. The cases have been grounded. Everything is fine
> >indoors. Outdoors, the noise floor goes way up. I get frequent
> >readings of 100 or more units (differs from sensor to sensor, worst
> >not necessarily the one pointed closet to sun), and short-time
> >averaging does not help too much.
>
> Start with a filter in front of the GP2D02 to filter out all but
the
> wavelength you want to receive.
>
>
> Jim H
properties (low distortions) like acrylic or polyester sheet.
ACJacques
pdop@y... wrote:
>
> Jim,
>
> Any ideas on where one could acquire such a filter?
>
> Thanks,
> Mike
>
> --- In basicstamps@y..., Jim Higgins <HigginsJ@s...> wrote:
> > At 14:51 07/23/01, pdop@y... wrote:
> >
> > >I am having trouble getting reliable results from the GP2D02
> sensors
> > >in sunlight. The cases have been grounded. Everything is fine
> > >indoors. Outdoors, the noise floor goes way up. I get frequent
> > >readings of 100 or more units (differs from sensor to sensor, worst
> > >not necessarily the one pointed closet to sun), and short-time
> > >averaging does not help too much.
> >
> > Start with a filter in front of the GP2D02 to filter out all but
> the
> > wavelength you want to receive.
> >
> >
> > Jim H
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and Body
of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>Any ideas on where one could acquire such a filter?
Two sources - assuming an infrared filter is needed:
1. Two layers of developed, but unexposed, color slide film. Sections
taken from the unexposed portion of the film leader would do nicely.
2. Rip apart an old TV remote and take the dark red filter from that. The
latter will transmit red light as well as IR.
Jim H
> I am having trouble getting reliable results from the GP2D02 sensors
> in sunlight. The cases have been grounded. Everything is fine
> indoors. Outdoors, the noise floor goes way up. I get frequent
> readings of 100 or more units (differs from sensor to sensor, worst
> not necessarily the one pointed closet to sun), and short-time
> averaging does not help too much.
>
> Any advice?
>
There are 2 things you can do to improve your results. First, put a little
'visor',
maybe an 3/4 of an inch long, on top of the sensor to help shade the optics.
The other is to put a piece of IR filter over the optics. You can use a piece of
unexposed (but developed) colour 35 mm film for this.
You should be aware that anything in front of the optics *can* affect the
readings you get -experiment indoors first.
Mark Hillier, VE6HVW
President, HVW Technologies Inc.
Canadian Distributors of Parallax Products and other Neat Stuff
Tel: (403)-730-8603 Fax: (403)-730-8903
See our NEW BASIC Stamp Prototyping tools !
http://www.hvwtech.com/stampstack.htm
Original Message
> >I am having trouble getting reliable results from the GP2D02 sensors
> >in sunlight. The cases have been grounded. Everything is fine
> >indoors. Outdoors, the noise floor goes way up. I get frequent
> >readings of 100 or more units (differs from sensor to sensor, worst
> >not necessarily the one pointed closet to sun), and short-time
> >averaging does not help too much.
>
> Start with a filter in front of the GP2D02 to filter out all but the
> wavelength you want to receive.
and see-thru -- it passes visible light. Exposed, developed color negative
film is dark and passes mostly I/R.
Original Message
> > I am having trouble getting reliable results from the GP2D02 sensors
> > in sunlight. The cases have been grounded. Everything is fine
> > indoors. Outdoors, the noise floor goes way up. I get frequent
> > readings of 100 or more units (differs from sensor to sensor, worst
> > not necessarily the one pointed closet to sun), and short-time
> > averaging does not help too much.
> There are 2 things you can do to improve your results. First, put a little
'visor',
> maybe an 3/4 of an inch long, on top of the sensor to help shade the
optics.
> The other is to put a piece of IR filter over the optics. You can use a
piece of
> unexposed (but developed) colour 35 mm film for this.
>
> You should be aware that anything in front of the optics *can* affect the
> readings you get -experiment indoors first.
>You sure about the film? unexposed, developed color negative film is amber
>and see-thru -- it passes visible light. Exposed, developed color negative
>film is dark and passes mostly I/R.
Exposed color negative film is indeed dark, but every reference on the
Internet I've seen to using developed film for an IR filter refers to using
unexposed color reversal (sometimes referred to as E-6 process) film; i.e.,
color SLIDE film - Ektachrome to be specific. There is probably a reason
that something few use is recommended over something everyone already has.
In any case, the guy asking has a working transmitter/receiver pair. It is
a trivial matter to insert assorted filter materials and test the
result. Hopefully he will report his findings.
Jim H
> and see-thru -- it passes visible light. Exposed, developed color negative
> film is dark and passes mostly I/R.
>
Pretty sure about that. After all, how do you uniformly expose the film ?
AC Jacques mentioned "frosting"; yes, it is possible that this can have a
diffusing effect. In fact, *anything* in front of the sensor can alter the
readings
you get, which is why I suggest the visor as the first option and the filter as
the second AND some testing in a controlled environment first.
It helps if you have an underdtanding on how the sensor works to help solve
the problem. I suggest you download the manual for our DIRRS kit which
uses this sensor; there is a full explanation in there, complete with diagrams.
It's at:
http://www.hvwtech.com/downloads.htm
Mark Hillier, VE6HVW
President, HVW Technologies Inc.
Canadian Distributors of Parallax Products and other Neat Stuff
Tel: (403)-730-8603 Fax: (403)-730-8903
See our NEW BASIC Stamp Prototyping tools !
http://www.hvwtech.com/stampstack.htm
> > You sure about the film? unexposed, developed color negative film is amber
> > and see-thru -- it passes visible light. Exposed, developed color negative
> > film is dark and passes mostly I/R.
>
>Pretty sure about that. After all, how do you uniformly expose the film ?
Take a full frame picture of a white piece of paper in daylight. Grossly
overexpose it at full aperture for 1/2 to several seconds. For less
exposure, but still uniform, use a shorter exposure. You can also use a
neutral grey card as the subject. But the call for use of UNEXPOSED
developed film arises because it is SLIDE film that should be
used. Without the emulsion, slide film is clear. Color negative film is
amber. Unexposed slide film blocks essentially all visible light, thus
preventing overload of the sensor in daylight. I won't swear negative film
won't work as an IR pass-filter, but I've never heard it recommended over
unexposed developed slide film before now.
>AC Jacques mentioned "frosting"; yes, it is possible that this can have a
>diffusing effect. In fact, *anything* in front of the sensor can alter the
>readings
>you get, which is why I suggest the visor as the first option and the
>filter as
>the second AND some testing in a controlled environment first.
If diffusion is a problem, there are easily findable sites selling glass
infrared filters for cameras. It is absolutely necessary to know the
wavelength of interest before buying one of these, and you may need to try
several sites to get detailed transmission data so you can select the best
filter. They cost about $40.
If anyone goes the glass filter route, get one with a mount diameter that
will fit your 35mm camera lens, or your Camcorder lens. The former offers
the option of taking some photos using Kodak's Infrared Ektachrome film -
if you can find it. You'll have to ask at a serious photo shop in a large
city. And you must ASK, since it will be in a freezer in the back, not on
the shelf. You can also get some very interesting false color effects with
this film using a deep yellow/orange filter such as an O2. Most if not all
camcorders are fairly sensitive to IR. You might find the best wavelength
for the sensor is not the best for the camcorder though.
remote controls? Would they not do the job? You should be able to pick
these up at thrift shops.
I would also modulate the beam so that stray IR noise would not affect the
data. A simple 25-100khz signal injected in the IR side, with a notch
filter on the receiver should take care of noise. Or am I way off base with
respect to the problem as described?
John :-#)#
At 11:42 AM 24/07/2001, you wrote:
>At 10:44 07/24/01, Mark Hillier wrote:
>
> > > You sure about the film? unexposed, developed color negative film is
> amber
> > > and see-thru -- it passes visible light. Exposed, developed color
> negative
> > > film is dark and passes mostly I/R.
> >
> >Pretty sure about that. After all, how do you uniformly expose the film ?
>
>Take a full frame picture of a white piece of paper in daylight. Grossly
---
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required.
Sorry about that.
> >Pretty sure about that. After all, how do you uniformly expose the film ?
>
> Take a full frame picture of a white piece of paper in daylight. Grossly
> overexpose it at full aperture for 1/2 to several seconds. For less
> exposure, but still uniform, use a shorter exposure. You can also use a
> neutral grey card as the subject. But the call for use of UNEXPOSED
> developed film arises because it is SLIDE film that should be
> used. Without the emulsion, slide film is clear. Color negative film is
> amber. Unexposed slide film blocks essentially all visible light, thus
> preventing overload of the sensor in daylight. I won't swear negative film
> won't work as an IR pass-filter, but I've never heard it recommended over
> unexposed developed slide film before now.
>
Mark Hillier, VE6HVW
President, HVW Technologies Inc.
Canadian Distributors of Parallax Products and other Neat Stuff
Tel: (403)-730-8603 Fax: (403)-730-8903
See our NEW BASIC Stamp Prototyping tools !
http://www.hvwtech.com/stampstack.htm
exposed so far. Since its negative film, exposing it to light makes it dark.
Original Message
> > You sure about the film? unexposed, developed color negative film is
amber
> > and see-thru -- it passes visible light. Exposed, developed color
negative
> > film is dark and passes mostly I/R.
> >
>
> Pretty sure about that. After all, how do you uniformly expose the film ?
film gets dark when exposed -- unexposed it would take on an amber tint.
The only difference I can see is slide film is clear with various color
pigments, while negative film is amber with various colored pigments.
Most of the I/R stuff I messed with a long time ago had a very dark amber
filter. Remotes and their related receivers now have a redish filter. If
know someone who works in a print shop, get some pieces of Rubylith.
Alternately you could go to a theatrical supply and buy colored gels.
Original Message
> >You sure about the film? unexposed, developed color negative film is
amber
> >and see-thru -- it passes visible light. Exposed, developed color
negative
> >film is dark and passes mostly I/R.
>
> Exposed color negative film is indeed dark, but every reference on the
> Internet I've seen to using developed film for an IR filter refers to
using
> unexposed color reversal (sometimes referred to as E-6 process) film;
i.e.,
> color SLIDE film - Ektachrome to be specific. There is probably a reason
> that something few use is recommended over something everyone already has.
>
> In any case, the guy asking has a working transmitter/receiver pair. It
is
> a trivial matter to insert assorted filter materials and test the
> result. Hopefully he will report his findings.