Hi,
I need to find out when someone walks up to a window sensing proximity
of about 2 meters from the window. I can't place the sensor on the
outside, so the sensor have to work through glass.
I have tested the long range distance sensor from Sharp - GP2Y0A02YK,
which works through glass. The problem is that it has a very narrow beam.
Does anyone have suggestions for alternative solutions?
/lars
proximity sensing through glass
Started by ●December 8, 2005
Reply by ●December 8, 20052005-12-08
Consider a microwave sensor, should be capable of detecting thru most
materials.
Its commonly used with better animatronics
Gory Corey
csminion@csmi...
http://www.MinionsWeb.com
http://www.Hallow-Links.com
http://groups.yahoo.com/group/Technical_Insanity/
http://groups.yahoo.com/group/EerieHaunts/
-----Original Message-----
From: basicx@basi... [mailto:basicx@basi...]On Behalf Of
larzyharzy
Sent: Thursday, December 08, 2005 3:32 PM
To: basicx@basi...
Subject: [BasicX] proximity sensing through glass Hi,
I need to find out when someone walks up to a window sensing proximity
of about 2 meters from the window. I can't place the sensor on the
outside, so the sensor have to work through glass.
I have tested the long range distance sensor from Sharp - GP2Y0A02YK,
which works through glass. The problem is that it has a very narrow beam.
Does anyone have suggestions for alternative solutions?
/lars SPONSORED LINKS Microprocessor Microcontrollers Basicx
Pic microcontrollers 8051 microprocessor ----
--
YAHOO! GROUPS LINKS
a.. ----
--
materials.
Its commonly used with better animatronics
Gory Corey
csminion@csmi...
http://www.MinionsWeb.com
http://www.Hallow-Links.com
http://groups.yahoo.com/group/Technical_Insanity/
http://groups.yahoo.com/group/EerieHaunts/
-----Original Message-----
From: basicx@basi... [mailto:basicx@basi...]On Behalf Of
larzyharzy
Sent: Thursday, December 08, 2005 3:32 PM
To: basicx@basi...
Subject: [BasicX] proximity sensing through glass Hi,
I need to find out when someone walks up to a window sensing proximity
of about 2 meters from the window. I can't place the sensor on the
outside, so the sensor have to work through glass.
I have tested the long range distance sensor from Sharp - GP2Y0A02YK,
which works through glass. The problem is that it has a very narrow beam.
Does anyone have suggestions for alternative solutions?
/lars SPONSORED LINKS Microprocessor Microcontrollers Basicx
Pic microcontrollers 8051 microprocessor ----
--
YAHOO! GROUPS LINKS
a.. ----
--
Reply by ●December 13, 20052005-12-13
I tested this Siemens micro wave sensor
http://digchip.com/datasheets/parts/datasheet/216/KMY24.php
but as far as I can see this can only detect moving objects. If a
person stands still in front of the window it doesn't register anything.
do you know of any radar sensors which can determine distance of
objects which are not moving?
/lars
--- In basicx@basi..., "Gory Corey @M..." <csminion@m...> wrote:
>
> Consider a microwave sensor, should be capable of detecting thru most
> materials.
> Its commonly used with better animatronics
>
> Gory Corey
> csminion@M...
> http://www.MinionsWeb.com
> http://www.Hallow-Links.com
> http://groups.yahoo.com/group/Technical_Insanity/
> http://groups.yahoo.com/group/EerieHaunts/
>
> -----Original Message-----
> From: basicx@basi... [mailto:basicx@basi...]On
Behalf Of
> larzyharzy
> Sent: Thursday, December 08, 2005 3:32 PM
> To: basicx@basi...
> Subject: [BasicX] proximity sensing through glass > Hi,
>
> I need to find out when someone walks up to a window sensing proximity
> of about 2 meters from the window. I can't place the sensor on the
> outside, so the sensor have to work through glass.
>
> I have tested the long range distance sensor from Sharp - GP2Y0A02YK,
> which works through glass. The problem is that it has a very
narrow beam.
>
> Does anyone have suggestions for alternative solutions?
>
> /lars > SPONSORED LINKS Microprocessor Microcontrollers Basicx
> Pic microcontrollers 8051 microprocessor >
----
> --
> YAHOO! GROUPS LINKS
>
> a.. >
----
> --
http://digchip.com/datasheets/parts/datasheet/216/KMY24.php
but as far as I can see this can only detect moving objects. If a
person stands still in front of the window it doesn't register anything.
do you know of any radar sensors which can determine distance of
objects which are not moving?
/lars
--- In basicx@basi..., "Gory Corey @M..." <csminion@m...> wrote:
>
> Consider a microwave sensor, should be capable of detecting thru most
> materials.
> Its commonly used with better animatronics
>
> Gory Corey
> csminion@M...
> http://www.MinionsWeb.com
> http://www.Hallow-Links.com
> http://groups.yahoo.com/group/Technical_Insanity/
> http://groups.yahoo.com/group/EerieHaunts/
>
> -----Original Message-----
> From: basicx@basi... [mailto:basicx@basi...]On
Behalf Of
> larzyharzy
> Sent: Thursday, December 08, 2005 3:32 PM
> To: basicx@basi...
> Subject: [BasicX] proximity sensing through glass > Hi,
>
> I need to find out when someone walks up to a window sensing proximity
> of about 2 meters from the window. I can't place the sensor on the
> outside, so the sensor have to work through glass.
>
> I have tested the long range distance sensor from Sharp - GP2Y0A02YK,
> which works through glass. The problem is that it has a very
narrow beam.
>
> Does anyone have suggestions for alternative solutions?
>
> /lars > SPONSORED LINKS Microprocessor Microcontrollers Basicx
> Pic microcontrollers 8051 microprocessor >
----
> --
> YAHOO! GROUPS LINKS
>
> a.. >
----
> --
Reply by ●December 13, 20052005-12-13
Hi
Just an exercise on complex solutions lol
A camera plus some simple visual recognition algorithm. Start out with a
vertical rectangle recognition.
Whichever sensor you choose, if you want to detect the presence of
something with no motion, then you need to compare data without that
presence against real-time data. whenever they're different beyond a
certain value, you've got a presence. Then you need to differentiate
between a person and any other presence, hence the
camera+pattern-recognition suggestion.
Placing at least one of the sensor (in case of emitter plus receiver)
outside would simplify things a lot. You could detect the presence by
detecting some beam being disrupted... (laser, ir).
Another (but more complicated approach) would be something similar to a
laser mic. Put an ultrasound emitter facing the window from the inside.
That will cause the glass to vibrate even if just a little. Now put a
reflective (and small) circular piece of tape on the window and point a
distance measuring device pointing to it. The theory is that the vibration
will make the air outside vibrate, but if there's anything in front of it,
it will vibrate off it and back to the glass. So the thing is, it will
vibrate a tiny bit more (or possibly cancel all vibration) if there's
something standing in front of the window.
Filipe
On 2005/12/13, at 16:27, larzyharzy wrote:
[]
Just an exercise on complex solutions lol
A camera plus some simple visual recognition algorithm. Start out with a
vertical rectangle recognition.
Whichever sensor you choose, if you want to detect the presence of
something with no motion, then you need to compare data without that
presence against real-time data. whenever they're different beyond a
certain value, you've got a presence. Then you need to differentiate
between a person and any other presence, hence the
camera+pattern-recognition suggestion.
Placing at least one of the sensor (in case of emitter plus receiver)
outside would simplify things a lot. You could detect the presence by
detecting some beam being disrupted... (laser, ir).
Another (but more complicated approach) would be something similar to a
laser mic. Put an ultrasound emitter facing the window from the inside.
That will cause the glass to vibrate even if just a little. Now put a
reflective (and small) circular piece of tape on the window and point a
distance measuring device pointing to it. The theory is that the vibration
will make the air outside vibrate, but if there's anything in front of it,
it will vibrate off it and back to the glass. So the thing is, it will
vibrate a tiny bit more (or possibly cancel all vibration) if there's
something standing in front of the window.
Filipe
On 2005/12/13, at 16:27, larzyharzy wrote:
[]
Reply by ●December 14, 20052005-12-14
--- In basicx@basi..., "Filipe Varela" <fcv@d...> wrote:
>
> Hi
>
> Just an exercise on complex solutions lol
There may be a quite simple and easy way. A PIR or Passive Infra Red
device [also called a Pyroelectric]. These are a primary sensor for
security devices and actually have silcon filters and lens [so glass
doesn't seem to be an obstacle]. They are set up to track movement
only of warm bodies against a cooler background.
In order to interface you need a quad opamp [an LM324] and a dual one-
shot. Together the PIR will not only detect movement but also
direction along it's primary axis [that could be either up and down
or left and right or something diagonal].
What you get are two outputs - one for each direction the motive
originates from. So it would only consume two pins on a BX-24.
The op-amps include adjustible gain for sensitity. The PIR has
already limited the portion of the spectrum to optimal for warm
blooded animals [which we are]. I happen to purchase two that are
suppose to be good to 30 meter! I haven't had time to build the
circuitry to test them out though.
>
> Hi
>
> Just an exercise on complex solutions lol
There may be a quite simple and easy way. A PIR or Passive Infra Red
device [also called a Pyroelectric]. These are a primary sensor for
security devices and actually have silcon filters and lens [so glass
doesn't seem to be an obstacle]. They are set up to track movement
only of warm bodies against a cooler background.
In order to interface you need a quad opamp [an LM324] and a dual one-
shot. Together the PIR will not only detect movement but also
direction along it's primary axis [that could be either up and down
or left and right or something diagonal].
What you get are two outputs - one for each direction the motive
originates from. So it would only consume two pins on a BX-24.
The op-amps include adjustible gain for sensitity. The PIR has
already limited the portion of the spectrum to optimal for warm
blooded animals [which we are]. I happen to purchase two that are
suppose to be good to 30 meter! I haven't had time to build the
circuitry to test them out though.
Reply by ●December 14, 20052005-12-14
> ... The PIR has already limited the portion of the spectrum to
optimal for warm blooded animals...
Hmmm. A warm-blooded animal like a human has the same thermal spectrum
signature as anything else at the same temperature, about 82 degreesF.
PIRs are actually spectrally pretty broad in the long-IR.
PIRs don't detect human motion when the human and the background are at
the same temperature. And even if detected during entry or exit motion,
a standing human will shortly disappear to the differential-detecting PIR.
Then there's the window glass that reflects long-IR well (making it
responsive to indoor change and motion) but might not pass it well. Tom
optimal for warm blooded animals...
Hmmm. A warm-blooded animal like a human has the same thermal spectrum
signature as anything else at the same temperature, about 82 degreesF.
PIRs are actually spectrally pretty broad in the long-IR.
PIRs don't detect human motion when the human and the background are at
the same temperature. And even if detected during entry or exit motion,
a standing human will shortly disappear to the differential-detecting PIR.
Then there's the window glass that reflects long-IR well (making it
responsive to indoor change and motion) but might not pass it well. Tom
Reply by ●December 15, 20052005-12-15
I think it is worth a try.
After all, he only wanted close to the window and movement.
I would put it as near to the glass as possible and shaded from
interior reflections.
Actually, the PIR reconizes changes in the IR from the background and
creates a spike. So I suppose a 'cooler object' on a hot background
might do something. They are highly sensitive to small differences
[less than a degree].
The PIRs that I purchased come with an interesting composite Fresnel
Lens. It has three rows of lens that target near, middle, and far.
Additonally they spread the view into a wider angle. The far is 30
meters [seems a bit much for me].
Temperature is filtered via a silicon filter in the unit to a
particlur band of IR. I suppose the filter could be removed and the
bandwidth would widen, but I would want to try for fear of damaging
the unit.
It is certainly easier than using a video camera and processing the
digital. More useful for a BX-24.
Try Googling 'Pyroelectrics' for more information. I am just a
beginner with these.
--- In basicx@basi..., Tom Becker <gtbecker@r...> wrote:
>
> > ... The PIR has already limited the portion of the spectrum to
> optimal for warm blooded animals...
>
> Hmmm. A warm-blooded animal like a human has the same thermal
spectrum
> signature as anything else at the same temperature, about 82
degreesF.
> PIRs are actually spectrally pretty broad in the long-IR.
>
> PIRs don't detect human motion when the human and the background
are at
> the same temperature. And even if detected during entry or exit
motion,
> a standing human will shortly disappear to the differential-
detecting PIR.
>
> Then there's the window glass that reflects long-IR well (making it
> responsive to indoor change and motion) but might not pass it well. > Tom
>
After all, he only wanted close to the window and movement.
I would put it as near to the glass as possible and shaded from
interior reflections.
Actually, the PIR reconizes changes in the IR from the background and
creates a spike. So I suppose a 'cooler object' on a hot background
might do something. They are highly sensitive to small differences
[less than a degree].
The PIRs that I purchased come with an interesting composite Fresnel
Lens. It has three rows of lens that target near, middle, and far.
Additonally they spread the view into a wider angle. The far is 30
meters [seems a bit much for me].
Temperature is filtered via a silicon filter in the unit to a
particlur band of IR. I suppose the filter could be removed and the
bandwidth would widen, but I would want to try for fear of damaging
the unit.
It is certainly easier than using a video camera and processing the
digital. More useful for a BX-24.
Try Googling 'Pyroelectrics' for more information. I am just a
beginner with these.
--- In basicx@basi..., Tom Becker <gtbecker@r...> wrote:
>
> > ... The PIR has already limited the portion of the spectrum to
> optimal for warm blooded animals...
>
> Hmmm. A warm-blooded animal like a human has the same thermal
spectrum
> signature as anything else at the same temperature, about 82
degreesF.
> PIRs are actually spectrally pretty broad in the long-IR.
>
> PIRs don't detect human motion when the human and the background
are at
> the same temperature. And even if detected during entry or exit
motion,
> a standing human will shortly disappear to the differential-
detecting PIR.
>
> Then there's the window glass that reflects long-IR well (making it
> responsive to indoor change and motion) but might not pass it well. > Tom
>
