tolltag like sensor for cat door
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Posts: 46,084
Hello,
I have a cat, and a cat door, and now other cats are entering my house.
This is a problem since I don't realy like cats, just the one that adopted
me. I'd like to put some sort of sensor on an automated cat door that
detects my cat's collar to only let in the one cat. I was thinking of
changing to a revolving style door because that might prevent other cats
tailgating" in. I'd probably hook the sensor or sensors up to a bs2.
I've been thinking of something like the anti-shoplifting sensors at
department stores that detect the metal foil sticker that is put on
merchandise, or something like the tolltags they now have on some tollways.
I've wondered for years, but have never found an answer to how these devices
work. Does anyone know more about these kind of sensors or have a better
solution all together?
Thanks,
Stewart
I have a cat, and a cat door, and now other cats are entering my house.
This is a problem since I don't realy like cats, just the one that adopted
me. I'd like to put some sort of sensor on an automated cat door that
detects my cat's collar to only let in the one cat. I was thinking of
changing to a revolving style door because that might prevent other cats
tailgating" in. I'd probably hook the sensor or sensors up to a bs2.
I've been thinking of something like the anti-shoplifting sensors at
department stores that detect the metal foil sticker that is put on
merchandise, or something like the tolltags they now have on some tollways.
I've wondered for years, but have never found an answer to how these devices
work. Does anyone know more about these kind of sensors or have a better
solution all together?
Thanks,
Stewart
Comments
stewlist@k... writes:
<< I have a cat, and a cat door, and now other cats are entering my house.
This is a problem since I don't realy like cats, just the one that adopted
me. I'd like to put some sort of sensor on an automated cat door that
detects my cat's collar to only let in the one cat. I was thinking of
changing to a revolving style door because that might prevent other cats
tailgating" in. I'd probably hook the sensor or sensors up to a bs2.
I've been thinking of something like the anti-shoplifting sensors at
department stores that detect the metal foil sticker that is put on
merchandise, or something like the tolltags they now have on some tollways.
I've wondered for years, but have never found an answer to how these devices
work. Does anyone know more about these kind of sensors or have a better
solution all together?
Thanks,
Stewart
>>
Stewart,
This is funny. I love it - "Basic Stamp scats cats". Post your solution on
the Parallax web site.
You may want to take a look at Smarthome.com or Homecontrols.com. I recall
seeing something like this on one of those. May be too expensive but you may
get some ideas from it. It is definitely an interesting project; I have a
Chihuahua :0)
Regards,
Max
know how pet doors work too...
They already sell pet doors that do this. Look at the TIRIS stuff (the Mobil
SpeedPass).
I think sharpened steel blades that dropped down over the opening would be a
better / cheaper deterrent for cats.
(just kidding!)
Original Message
> I have a cat, and a cat door, and now other cats are entering my house.
> This is a problem since I don't realy like cats, just the one that adopted
> me. I'd like to put some sort of sensor on an automated cat door that
> detects my cat's collar to only let in the one cat. I was thinking of
> changing to a revolving style door because that might prevent other cats
> tailgating" in. I'd probably hook the sensor or sensors up to a bs2.
>
> I've been thinking of something like the anti-shoplifting sensors at
> department stores that detect the metal foil sticker that is put on
> merchandise, or something like the tolltags they now have on some
tollways.
> I've wondered for years, but have never found an answer to how these
devices
> work. Does anyone know more about these kind of sensors or have a better
> solution all together?
a bunch of very strong magnets to the cats colar and detect them near the
door? Not quite as elegant as the "tolltag" but probably less costly too.
-- Jon Williams
In a message dated 11/5/01 5:13:46 PM Central Standard Time,
stewlist@k... writes:
> I have a cat, and a cat door, and now other cats are entering my house.
> This is a problem since I don't realy like cats, just the one that adopted
> me. I'd like to put some sort of sensor on an automated cat door that
> detects my cat's collar to only let in the one cat. I was thinking of
> changing to a revolving style door because that might prevent other cats
> tailgating" in. I'd probably hook the sensor or sensors up to a bs2.
>
> I've been thinking of something like the anti-shoplifting sensors at
> department stores that detect the metal foil sticker that is put on
> merchandise, or something like the tolltags they now have on some tollways.
> I've wondered for years, but have never found an answer to how these devices
> work. Does anyone know more about these kind of sensors or have a better
> solution all together?
>
[noparse][[/noparse]Non-text portions of this message have been removed]
cat can bring home. I just couldn't resist the image of this cat with
a spiked collar from all the nails and things.
I really do like the idea. A simple detector around the door frame
would work very well.
Mike
>Perhaps a simpler approach will be more cost effective. Maybe you could glue
>a bunch of very strong magnets to the cats colar and detect them near the
>door? Not quite as elegant as the "tolltag" but probably less costly too.
>
>-- Jon Williams
>
>
>
>In a message dated 11/5/01 5:13:46 PM Central Standard Time,
>stewlist@k... writes:
>
>
>> I have a cat, and a cat door, and now other cats are entering my house.
>> This is a problem since I don't realy like cats, just the one that adopted
>> me. I'd like to put some sort of sensor on an automated cat door that
>> detects my cat's collar to only let in the one cat. I was thinking of
>> changing to a revolving style door because that might prevent other cats
>> tailgating" in. I'd probably hook the sensor or sensors up to a bs2.
>>
>> I've been thinking of something like the anti-shoplifting sensors at
>> department stores that detect the metal foil sticker that is put on
>> merchandise, or something like the tolltags they now have on some tollways.
>> I've wondered for years, but have never found an answer to how these devices
>> work. Does anyone know more about these kind of sensors or have a better
>> solution all together?
>>
>
>
>
>
>[noparse][[/noparse]Non-text portions of this message have been removed]
>
>
>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/
> would work very well.
>
> Mike
>
>
>
> >Perhaps a simpler approach will be more cost effective. Maybe you could
glue
> >a bunch of very strong magnets to the cats colar and detect them near the
> >door? Not quite as elegant as the "tolltag" but probably less costly
too.
> >
> >-- Jon Williams
> >
> >
Is this a hall effect sensor? How do you detect a magnetic field?
thanks
Burt
> Hello,
>
> I have a cat, and a cat door, and now other cats are entering my
house.
> This is a problem since I don't realy like cats, just the one that
adopted
> me. I'd like to put some sort of sensor on an automated cat door
that
> detects my cat's collar to only let in the one cat. I was thinking
of
> changing to a revolving style door because that might prevent other
cats
> tailgating" in. I'd probably hook the sensor or sensors up to a
bs2.
>
> I've been thinking of something like the anti-shoplifting sensors at
> department stores that detect the metal foil sticker that is put on
> merchandise, or something like the tolltags they now have on some
tollways.
> I've wondered for years, but have never found an answer to how
these devices
> work. Does anyone know more about these kind of sensors or have a
better
> solution all together?
>
> Thanks,
> Stewart
I don't think you need magnets. Just put a heavy steel collar on the
cat and use a metal detector type of circuit - the steel should
trigger it. Of course the poor cat won't be able to hold his head up
with that heavy collar around his neck, but that might keep him from
running around too much. ;-)
On Tue, 6 Nov 2001 burtsz@a... wrote:
> Hi Stewart, Bar code that cat and install a bar code scanner in the door.
That would be one COOL tatoo on top of the cat's head! :-)
--- Jay
"Those who sacrifice essential liberty to obtain a temporary safety
end up with neither." -- Ben Franklin (1759)
+
+
| Jay Nugent jjn@n... (734)971-1076 (734)971-4529/Fax |
| Nugent Telecommunications [noparse][[/noparse]www.nuge.com] (734)649-0850/Cell |
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| LinuxNIC, Inc. [noparse][[/noparse]www.linuxnic.net] Registrar of the .linux TLD |
+
+
8:00am up 57 days, 18:03, 7 users, load average: 0.09, 0.04, 0.02
though, that sounds a little more reliable. Anyone know the range of hall
effect sensors? The door is 6 inches wide so with sensors on each side, the
max range would be 3".
To keep the cat from leaving the yard, my next project will be to hook up a
little GPS receiver to a collar embedded tazer gun.
stewart
> Hi Stewart, Bar code that cat and install a bar code scanner in the door.
Burt
realization that we often do things simply because we can. The decision as
to whether or not a project will be undertaken should begin with an analysis
of the problem. Before burning grey matter on the control method for the cat
door, I would have guessed that Stewart's cat may simply need to be spayed
or neutered.
It wouldn't be a fun project, but it might solve the underlying
problem.......
So, how domesticated is your cat Stew?
Chris
>
Original Message
> From: Stewart Mayer [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=cg1FbFjmAs4zz09FMJRu5NboFHAcIG_o6wfKHZFORq8kBdmtfQ5-pgPN5JlW5tJsRcSMZ-RyLQmvCPKGogZhJkw]stewlist@k...[/url
> Sent: Monday, November 05, 2001 6:14 PM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] tolltag like sensor for cat door
>
>
> Hello,
>
> I have a cat, and a cat door, and now other cats are entering
> my house.
> This is a problem since I don't realy like cats, just the one
> that adopted
> me. I'd like to put some sort of sensor on an automated cat door that
> detects my cat's collar to only let in the one cat. I was thinking of
> changing to a revolving style door because that might prevent
> other cats
> tailgating" in. I'd probably hook the sensor or sensors up to a bs2.
>
> I've been thinking of something like the anti-shoplifting sensors at
> department stores that detect the metal foil sticker that is put on
> merchandise, or something like the tolltags they now have on
> some tollways.
> I've wondered for years, but have never found an answer to
> how these devices
> work. Does anyone know more about these kind of sensors or
> have a better
> solution all together?
>
> Thanks,
> Stewart
>
> 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/
>
>
>
inch or so would be about it. I would place it on a little arm that
sticks out above the door and place the magnet at the top of the
collar.
Or maybe a nose print scanner!
Mike
>That is realy funny! And might work too. I'm leaning towards the magnets
>though, that sounds a little more reliable. Anyone know the range of hall
>effect sensors? The door is 6 inches wide so with sensors on each side, the
>max range would be 3".
>
>To keep the cat from leaving the yard, my next project will be to hook up a
>little GPS receiver to a collar embedded tazer gun.
>
>stewart
--
Pisani Graphics Inc.
Kimberly WI 54136
920-730-0014
> >though, that sounds a little more reliable. Anyone know the range of hall
> >effect sensors? The door is 6 inches wide so with sensors on each side, the
> >max range would be 3".
Without getting into fancy circuit techniques, I think the most
sensitive way to detect a weak magnetic field is with a compass.
Detect the motion of the compass needle optically. You can easily
get 3" distance from a small supermagnet. However, there _is_ the
issue of the poor cat coming home bristling with nails and staples.
>I've been thinking of something like the anti-shoplifting sensors at
> department stores that detect the metal foil sticker that is put on
> merchandise, or something like the tolltags they now have on some tollways.
> I've wondered for years, but have never found an answer to how these devices
The ones at dept stores are passive resonant circuits, usually with a
PIN diode in the circuit so that they reradiate energy at a harmonic.
The exit door excites the fundamental and listens for the harmonic.
A simple resonant circuit can also work for short range, with a
resonance detector. The fancier ones like for animal PIT tags and
the toll transponders absorb incoming energy and uses it to power a
circuit that retransmits a digital ID code.
>Or maybe a nose print scanner!
voice print scanner?!
cat in place while he gets a retina scan.
If the robotic arm is strong enough it can toss the occasional racoon
into the next county.
--- In basicstamps@y..., "Stewart Mayer" <stewlist@k...> wrote:
> Hello,
>
> I have a cat, and a cat door, and now other cats are entering my
house.
> This is a problem since I don't realy like cats, just the one that
adopted
> me. I'd like to put some sort of sensor on an automated cat door
that
> detects my cat's collar to only let in the one cat. I was thinking
of
> changing to a revolving style door because that might prevent other
cats
> tailgating" in. I'd probably hook the sensor or sensors up to a
bs2.
>
> I've been thinking of something like the anti-shoplifting sensors at
> department stores that detect the metal foil sticker that is put on
> merchandise, or something like the tolltags they now have on some
tollways.
> I've wondered for years, but have never found an answer to how
these devices
> work. Does anyone know more about these kind of sensors or have a
better
> solution all together?
>
> Thanks,
> Stewart
with the cat stuck to the roof of the car. Hope those magnets hold at 50
MPH.
A few random thoughts...
Actually some one brought up bar coding. I recall an article years ago
about an researcher studding bees. They glued tiny bar codes to their backs
and placed a scanner over the entrance to the hive. He was able to track
individual bees entering and leaving.
On a more humane level I'd avoid putting a collar on a cat. After having
removed more than one dead cat from brush after having tangled their collar.
Although I do understand local laws may require this. I live in a rural
area so this is not a problem.
My niece is a vet and they have tagged their animals with a passive
responder that works just like the tags at the stores. I wonder how
difficult it would be to build a detector for this? (I believe it is
inserted below the dermal layer of skin)
Mike Witherspoon
Original Message
From: Mike Davey [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=ZrTx31jDB4ZjbOWCBCKtSlmnfUZ0HNaAb768TYwOQeQ7gfFNgkxcfYiE0TrO57JYvCEXnfZRPw]mdavey@n...[/url
Sent: Monday, November 05, 2001 7:27 PM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] tolltag like sensor for cat door
I really like this idea, and think of all the nails and old cans your
cat can bring home. I just couldn't resist the image of this cat with
a spiked collar from all the nails and things.
I really do like the idea. A simple detector around the door frame
would work very well.
Mike
>Perhaps a simpler approach will be more cost effective. Maybe you could
glue
>a bunch of very strong magnets to the cats colar and detect them near the
>door? Not quite as elegant as the "tolltag" but probably less costly too.
>
>-- Jon Williams
>
>
>
>In a message dated 11/5/01 5:13:46 PM Central Standard Time,
>stewlist@k... writes:
>
>
>> I have a cat, and a cat door, and now other cats are entering my house.
>> This is a problem since I don't realy like cats, just the one that
adopted
>> me. I'd like to put some sort of sensor on an automated cat door that
>> detects my cat's collar to only let in the one cat. I was thinking of
>> changing to a revolving style door because that might prevent other cats
>> tailgating" in. I'd probably hook the sensor or sensors up to a bs2.
>>
>> I've been thinking of something like the anti-shoplifting sensors at
>> department stores that detect the metal foil sticker that is put on
>> merchandise, or something like the tolltags they now have on some
tollways.
>> I've wondered for years, but have never found an answer to how these
devices
>> work. Does anyone know more about these kind of sensors or have a
better
>> solution all together?
>>
>
>
>
>
>[noparse][[/noparse]Non-text portions of this message have been removed]
>
>
>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/
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/
idea of using a speed pass type device, like I see being used at my local
Mobil gas station. These devices are easily interrogated with a RF
transponder. This time I suggested using a bar code (totally passive) which
could be read with a simple low cost scanner. The question is where does the
bar code mounted or attached so that it does not interfere with the cat's
natural movements or habits. And yes, several years ago, researchers did
mount very small transmitters onto the backs of bees to study their
movements. I believe that a search on the NASA website would reveal this
information and perhaps insight into other approaches. Keeping the racoons
out is yet another problem. Perhaps a non-lethal electrical jolt would keep
them out. Or putting pizza on the neighbors lawn. Burt
hook up to a stamp. Anyone seen anything like this for sale in the
US?
http://www.stefan-mayer.com/Lcsing.htm
How about a three door system. The first door lets any animal in and
closes behind it so that there is a "waiting area". A pressure or
opto-interrupt switch detects the presence of an animal in the
waiting area. Then if the magnetic field is detected, the second
door opens to let the cat in. If the pressure switch is activated,
but no magnetic field is detected, the floor swings open to drop the
animal into a tub of water underneath. Effective without permanent
damage.
Oh, I forgot, a digital camera is also hooked up to take a picture of
all animals getting dunked.
Stewart
On Tue, 6 Nov 2001 08:49:43 -0800, Witherspoon, Michael J wrote:
>Boy, gotta love that human imagination. Picture the neighbor
driving off
>with the cat stuck to the roof of the car. Hope those magnets hold
at 50
>MPH.
>
>A few random thoughts...
>
>Actually some one brought up bar coding. I recall an article years
ago
>about an researcher studding bees. They glued tiny bar codes to
their backs
>and placed a scanner over the entrance to the hive. He was able to
track
>individual bees entering and leaving.
>
>On a more humane level I'd avoid putting a collar on a cat. After
having
>removed more than one dead cat from brush after having tangled their
collar.
>Although I do understand local laws may require this. I live in a
rural
>area so this is not a problem.
>
>My niece is a vet and they have tagged their animals with a passive
>responder that works just like the tags at the stores. I wonder how
>difficult it would be to build a detector for this? (I believe it is
>inserted below the dermal layer of skin)
>
>
>Mike Witherspoon
>
>
>
Original Message
>From: Mike Davey [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=QjgK2upEp8HkD9qArbRkqJwgCP_2CbUpcqq4529SI97xRQbkRpehyN7bIRLAOQAK5g5iE5ZgBHI_oPLQ]mdavey@n...[/url
>Sent: Monday, November 05, 2001 7:27 PM
>To: basicstamps@yahoogroups.com
>Subject: Re: [noparse][[/noparse]basicstamps] tolltag like sensor for cat door
>
>
>I really like this idea, and think of all the nails and old cans
your
>cat can bring home. I just couldn't resist the image of this cat
with
>a spiked collar from all the nails and things.
>
>I really do like the idea. A simple detector around the door frame
>would work very well.
>
>Mike
>
>
>
>>Perhaps a simpler approach will be more cost effective. Maybe you
could
>glue
>>a bunch of very strong magnets to the cats colar and detect them
near the
>>door? Not quite as elegant as the "tolltag" but probably less
costly too.
>>
>>-- Jon Williams
>>
>>
>>
>>In a message dated 11/5/01 5:13:46 PM Central Standard Time,
>>stewlist@k... writes:
>>
>>
>>> I have a cat, and a cat door, and now other cats are entering my
house.
>>> This is a problem since I don't realy like cats, just the one
that
>adopted
>>> me. I'd like to put some sort of sensor on an automated cat door
that
>>> detects my cat's collar to only let in the one cat. I was
thinking of
>>> changing to a revolving style door because that might prevent
other cats
>>> tailgating" in. I'd probably hook the sensor or sensors up to a
bs2.
>>>
>>> I've been thinking of something like the anti-shoplifting sensors
at
>>> department stores that detect the metal foil sticker that is put
on
>>> merchandise, or something like the tolltags they now have on some
>tollways.
>>> I've wondered for years, but have never found an answer to how
these
>devices
>>> work. Does anyone know more about these kind of sensors or have
a
>better
>>> solution all together?
>>>
>>
>>
>>
>>
>>[noparse][[/noparse]Non-text portions of this message have been removed]
>>
>>
>>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/
>
>
>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/
>
>
>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.
>
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>Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
>
>
--
Stewart Mayer, stewlist@k... on 11/06/2001
What about some sort of reflector on the top of the collar? If the collar
has tags on it and the reflector is light enough, it should stay on top. Use
some super-bright LED's and a photocell to detect.
Original Message
> Hi Stewart, Bar code that cat and install a bar code scanner in the door.
& Volts. It involves controlling a circular saw with I2C protocol...
I actually found some automated pet doors for as cheap as $50, about
the same price as stamp without the work, but the ready made cat
doors don't include the torture options that are available in a home
brew. I'll probably buy the door [noparse]:([/noparse]
Stewart
>While taking part in a new products discussion recently, I came to
>the
>realization that we often do things simply because we can. The
>decision as
>to whether or not a project will be undertaken should begin with an
>analysis
>of the problem. Before burning grey matter on the control method for
>the cat
>door, I would have guessed that Stewart's cat may simply need to be
>spayed
>or neutered.
>It wouldn't be a fun project, but it might solve the underlying
>problem.......
>So, how domesticated is your cat Stew?
>
>Chris
>
>>
Original Message
>> From: Stewart Mayer [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=VByEll1y4-WX1BndFxK_ed9mAltPMLx9RZgLXf66EhlhLKjV31eoN2Dp-WrFTmNHNMHkQgSfRtC8wUcupz4g96s]stewlist@k...[/url
>> Sent: Monday, November 05, 2001 6:14 PM
>> To: basicstamps@yahoogroups.com
>> Subject: [noparse][[/noparse]basicstamps] tolltag like sensor for cat door
>>
>>
>> Hello,
>>
>> I have a cat, and a cat door, and now other cats are entering
>> my house.
>> This is a problem since I don't realy like cats, just the one
>> that adopted
>> me. I'd like to put some sort of sensor on an automated cat door
>>that
>> detects my cat's collar to only let in the one cat. I was
>>thinking of
>> changing to a revolving style door because that might prevent
>> other cats
>> tailgating" in. I'd probably hook the sensor or sensors up to a
>>bs2.
>>
>> I've been thinking of something like the anti-shoplifting sensors
>>at
>> department stores that detect the metal foil sticker that is put
on
>> merchandise, or something like the tolltags they now have on
>> some tollways.
>> I've wondered for years, but have never found an answer to
>> how these devices
>> work. Does anyone know more about these kind of sensors or
>> have a better
>> solution all together?
>>
>> Thanks,
>> Stewart
>>
>> 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/
>>
>>
>>
>
>
>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/
>
>
--
Stewart Mayer, stewlist@k... on 11/06/2001
to the
> realization that we often do things simply because we can. The
decision as
> to whether or not a project will be undertaken should begin
with an analysis
> of the problem.
Years ago when microprocessors first became affordable I heard a
guy describe the engineers in his department putting the latest
micro on the conference room table and saying "Wow! What can we
build around this new XXXX microprocessor?" He summed up a lot of
projects and products by concluding that "The State of the Art
has exceeded the State of the Need."
The up side to a certain amount of this thread is that although a
lot (most?) of the ideas may not be too practical for the pet
door they may give someone an idea bout solving another problem
he/she has been pondering.
Tim
I saw a completed project on here a few months
ago.
The Gentleman who did make such a door had three
cats (I think) and posted not only a great set of
pictures but also the concept and electronics.
He counted times in, out, duration for each...
really cool .
He did a really professional job and it is well worth
searching that link.
Dave
--- In basicstamps@y..., "Stewart Mayer" <stewlist@k...> wrote:
> Hello,
>
> I have a cat, and a cat door, and now other cats are entering my
house.
> This is a problem since I don't realy like cats, just the one that
adopted
> me. I'd like to put some sort of sensor on an automated cat door
that
> detects my cat's collar to only let in the one cat. I was thinking
of
> changing to a revolving style door because that might prevent other
cats
> tailgating" in. I'd probably hook the sensor or sensors up to a
bs2.
>
> I've been thinking of something like the anti-shoplifting sensors at
> department stores that detect the metal foil sticker that is put on
> merchandise, or something like the tolltags they now have on some
tollways.
> I've wondered for years, but have never found an answer to how
these devices
> work. Does anyone know more about these kind of sensors or have a
better
> solution all together?
>
> Thanks,
> Stewart
This may be the most creative group I've ever had the privilege of
corresponding with. Sometimes I can even blurt out my latest
brain-flatulence without serious repercussions, so add tolerant to the list
of communal qualities. Diversity is definitely a good thing....
>
Original Message
> From: Tim McDonough [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=ALxaHg-C7Z01bMdc-QLJez2HbrLSXX5xBvQEBUOYRBr8XjbrsESt18S3oT22Sa-_Sg6RQNE6oXxxMJbw]tim@m...[/url
> Sent: Tuesday, November 06, 2001 11:09 PM
> To: basicstamps@yahoogroups.com
> Subject: Re: [noparse][[/noparse]basicstamps] tolltag like sensor for cat door
>
>
> > While taking part in a new products discussion recently, I came
> to the
> > realization that we often do things simply because we can. The
> decision as
> > to whether or not a project will be undertaken should begin
> with an analysis
> > of the problem.
>
> Years ago when microprocessors first became affordable I heard a
> guy describe the engineers in his department putting the latest
> micro on the conference room table and saying "Wow! What can we
> build around this new XXXX microprocessor?" He summed up a lot of
> projects and products by concluding that "The State of the Art
> has exceeded the State of the Need."
>
> The up side to a certain amount of this thread is that although a
> lot (most?) of the ideas may not be too practical for the pet
> door they may give someone an idea bout solving another problem
> he/she has been pondering.
>
> Tim
>
>
>
> 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.
>
>
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> http://docs.yahoo.com/info/terms/
>
>
>
>mount very small transmitters onto the backs of bees to study their
>movements. I believe that a search on the NASA website would reveal this
>information and perhaps insight into other approaches.
I have a special interest in this because I too worked on tagging
bumblebees when I was in grad school. I made small self resonant LC
circuits by winding coils of #40 gage wire around numbered drill
bits. The coil was glued on a bees' thorax. The detection system
operated by scanning a range of frequencies around 300mhz and looking
for the peaks where tags absorbed energy. The tags were about 2mm
diameter and weighed 5 milligram (compared to bee's weight from 70 to
1000 milligrams). The detection range was near field, less than 2
cm, as the bees went in and out of the nest. We studied things like
how long individual bees spent out on foraging trips. We also wanted
to weigh the bees as they went in and out, but I never got that
working right.
One German researcher at the time glued small hemispheres of ferrite
or iron (not a permanent magnet!) onto a bees' thorax, and the
detector looked for changes in magnetic permeability when the bee
walked by.
Here are a couple of modern bee tagging links:
http://www2.ic.ornl.gov/pdf/infrared.pdf
These guys at Oak Ridge put a 9 solar cells of 1mm^2 each in series
(4.5 volts, 10 microamps in full sun), a 1 uf storage capacitor, a
relaxation oscillator, and a laser diode on the back of a honeybee,
so that the laser blinks could be detected (it was said) at a
distance of 1200 meters with an 8 inch telescope. I find it almost
unbelievable! Say, 10 microamps current into the capacitor to charge
it up 2 volts once every 20 seconds. What happens when the bee
changes direction? I tend to be sceptical about these things. There
are so many practical difficulties. But what a concept.
http://www.pnl.gov/news/1999/99-13.htm
And at Pacific NW lab they use a radio backscatter tag. They think
the bees will help the military locate unexploded landmines. Oh God
save us!
Here is are more links on transponders:
http://www.rapidttp.com/transponder/
-- regards,
Tracy Allen
electronically monitored ecosystems
mailto:tracy@e...
http://www.emesystems.com
one of them detects the cat *as it goes* through the door.
Meaning that the cat has to be actually *in* the door to be
detected. Meaning that any cat can get *in* the door with or
without detection. You need a way to detect the cat *before he
reaches* the door from the outside and unlock it. This would only
need to be a one-way lock. If he is in the house, he can go out
freely, but if he is outdside it requires the unlocker before the door
will actually open.
JMTCW. . .
Doug
On 6 Nov 2001, at 8:42, Stewart Mayer wrote:
> That is realy funny! And might work too. I'm leaning towards the
> magnets though, that sounds a little more reliable. Anyone know the
> range of hall effect sensors? The door is 6 inches wide so with
> sensors on each side, the max range would be 3".
>
> To keep the cat from leaving the yard, my next project will be to hook
> up a little GPS receiver to a collar embedded tazer gun.
>
> stewart
>
>
> > Hi Stewart, Bar code that cat and install a bar code scanner in the
> > door.
> Burt
>
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>
>
and not detect much of anything in range but put some reflective
tape on the cat's collar and that should make the IR detect the cat
but not detect other cats. Especially darker colored ones.
JATCW
On 6 Nov 2001, at 7:52, Tracy Allen wrote:
> > >That is realy funny! And might work too. I'm leaning towards the
> > >magnets though, that sounds a little more reliable. Anyone know
> > >the range of hall effect sensors? The door is 6 inches wide so
> > >with sensors on each side, the max range would be 3".
>
> Without getting into fancy circuit techniques, I think the most
> sensitive way to detect a weak magnetic field is with a compass.
> Detect the motion of the compass needle optically. You can easily get
> 3" distance from a small supermagnet. However, there _is_ the issue
> of the poor cat coming home bristling with nails and staples.
>
> >I've been thinking of something like the anti-shoplifting sensors at
> > department stores that detect the metal foil sticker that is put on
> > merchandise, or something like the tolltags they now have on some
> > tollways. I've wondered for years, but have never found an answer to
> > how these devices
>
> The ones at dept stores are passive resonant circuits, usually with a
> PIN diode in the circuit so that they reradiate energy at a harmonic.
> The exit door excites the fundamental and listens for the harmonic. A
> simple resonant circuit can also work for short range, with a
> resonance detector. The fancier ones like for animal PIT tags and
> the toll transponders absorb incoming energy and uses it to power a
> circuit that retransmits a digital ID code.
>
> >Or maybe a nose print scanner!
>
> voice print scanner?!
>
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject
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>
>
door and tune it so that it resonates with itself (cancels itself out)
then put a small ring of wire inside the cat's collar and make it so
that if the cat's collar is fastened the ring is a shorted loop. The
cat passes the door, and the detector quits cancelling itself.
Cheap metal detectors work by varying the frequency of the
oscillator in an L-C circuit and you 'hear' the difference. This is
similar to what I mean, only your circuit detects the frequency
change.
JYATCW
On 6 Nov 2001, at 8:49, Witherspoon, Michael J wrote:
> Boy, gotta love that human imagination. Picture the neighbor driving
> off with the cat stuck to the roof of the car. Hope those magnets
> hold at 50 MPH.
>
> A few random thoughts...
>
> Actually some one brought up bar coding. I recall an article years
> ago about an researcher studding bees. They glued tiny bar codes to
> their backs and placed a scanner over the entrance to the hive. He was
> able to track individual bees entering and leaving.
>
> On a more humane level I'd avoid putting a collar on a cat. After
> having removed more than one dead cat from brush after having tangled
> their collar. Although I do understand local laws may require this. I
> live in a rural area so this is not a problem.
>
> My niece is a vet and they have tagged their animals with a passive
> responder that works just like the tags at the stores. I wonder how
> difficult it would be to build a detector for this? (I believe it is
> inserted below the dermal layer of skin)
>
>
> Mike Witherspoon
>
>
>
Original Message
> From: Mike Davey [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=xY7pbrrj3dR0XzYzUbH23PkX-bzBRrwzk3iYnqwegsNr62zDqtLl35QPSxyu9nVkzk0KEH-aN7maQzo]mdavey@n...[/url
> Sent: Monday, November 05, 2001 7:27 PM
> To: basicstamps@yahoogroups.com
> Subject: Re: [noparse][[/noparse]basicstamps] tolltag like sensor for cat door
>
>
> I really like this idea, and think of all the nails and old cans your
> cat can bring home. I just couldn't resist the image of this cat with
> a spiked collar from all the nails and things.
>
> I really do like the idea. A simple detector around the door frame
> would work very well.
>
> Mike
>
>
>
> >Perhaps a simpler approach will be more cost effective. Maybe you
> >could
> glue
> >a bunch of very strong magnets to the cats colar and detect them near
> >the door? Not quite as elegant as the "tolltag" but probably less
> >costly too.
> >
> >-- Jon Williams
> >
> >
> >
> >In a message dated 11/5/01 5:13:46 PM Central Standard Time,
> >stewlist@k... writes:
> >
> >
> >> I have a cat, and a cat door, and now other cats are entering my
> >> house. This is a problem since I don't realy like cats, just the
> >> one that
> adopted
> >> me. I'd like to put some sort of sensor on an automated cat door
> >> that detects my cat's collar to only let in the one cat. I was
> >> thinking of changing to a revolving style door because that might
> >> prevent other cats tailgating" in. I'd probably hook the sensor
> >> or sensors up to a bs2.
> >>
> >> I've been thinking of something like the anti-shoplifting sensors
> >> at department stores that detect the metal foil sticker that is
> >> put on merchandise, or something like the tolltags they now have
> >> on some
> tollways.
> >> I've wondered for years, but have never found an answer to how
> >> these
> devices
> >> work. Does anyone know more about these kind of sensors or have a
> better
> >> solution all together?
> >>
> >
> >
> >
> >
> >[noparse][[/noparse]Non-text portions of this message have been removed]
> >
> >
> >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/
>
>
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>
>
I haven't read all the posts so please forgive if this has been mentioned.
But, what about the 'under the skin', 'grain of rice' -- sized, pet markers,
that
are already availble for dogs???
Could a small mat be made to detect these things?? you could place this in
front of the pet door, to check for your particular cat,
I guess you might have to drill him in the belly with the sensor, but it
only goes
under the skin....
(btw - have you seen the story about the 60's bionic cat that the cia used
to
spy on the soviets??, apparently they placed a sensitive microphone, along
with batteries, and an antenna in the tail, into a cat, that they would then
send
to the embassy window sill)
now that's catty!!
Original Message
From: <veewee77@a...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, November 07, 2001 11:26 AM
Subject: Re: [noparse][[/noparse]basicstamps] tolltag like sensor for cat door
> Only thing I see worng with these detector systems, is that every
> one of them detects the cat *as it goes* through the door.
> Meaning that the cat has to be actually *in* the door to be
> detected. Meaning that any cat can get *in* the door with or
> without detection. You need a way to detect the cat *before he
> reaches* the door from the outside and unlock it. This would only
> need to be a one-way lock. If he is in the house, he can go out
> freely, but if he is outdside it requires the unlocker before the door
> will actually open.
>
> JMTCW. . .
>
> Doug
>
>
> On 6 Nov 2001, at 8:42, Stewart Mayer wrote:
>
> > That is realy funny! And might work too. I'm leaning towards the
> > magnets though, that sounds a little more reliable. Anyone know the
> > range of hall effect sensors? The door is 6 inches wide so with
> > sensors on each side, the max range would be 3".
> >
> > To keep the cat from leaving the yard, my next project will be to hook
> > up a little GPS receiver to a collar embedded tazer gun.
> >
> > stewart
> >
> >
> > > Hi Stewart, Bar code that cat and install a bar code scanner in the
> > > door.
> > Burt
> >
> > 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/
> >
> >
>
>
>
>
> 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.
>
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>
>
The guys at Oak Ridge mounting blinking laser diodes on honey bees could
have saved some effort by starting with fireflies [noparse]:)[/noparse].
Dennis
Original Message
From: "Tracy Allen" <tracy@e...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, November 07, 2001 12:33 AM
Subject: Re: [noparse][[/noparse]basicstamps] tolltag like sensor for cat door
> > And yes, several years ago, researchers did
> >mount very small transmitters onto the backs of bees to study their
> >movements. I believe that a search on the NASA website would reveal this
> >information and perhaps insight into other approaches.
>
>
> I have a special interest in this because I too worked on tagging
> bumblebees when I was in grad school. I made small self resonant LC
> circuits by winding coils of #40 gage wire around numbered drill
> bits. The coil was glued on a bees' thorax. The detection system
> operated by scanning a range of frequencies around 300mhz and looking
> for the peaks where tags absorbed energy. The tags were about 2mm
> diameter and weighed 5 milligram (compared to bee's weight from 70 to
> 1000 milligrams). The detection range was near field, less than 2
> cm, as the bees went in and out of the nest. We studied things like
> how long individual bees spent out on foraging trips. We also wanted
> to weigh the bees as they went in and out, but I never got that
> working right.
>
> One German researcher at the time glued small hemispheres of ferrite
> or iron (not a permanent magnet!) onto a bees' thorax, and the
> detector looked for changes in magnetic permeability when the bee
> walked by.
>
> Here are a couple of modern bee tagging links:
>
> http://www2.ic.ornl.gov/pdf/infrared.pdf
> These guys at Oak Ridge put a 9 solar cells of 1mm^2 each in series
> (4.5 volts, 10 microamps in full sun), a 1 uf storage capacitor, a
> relaxation oscillator, and a laser diode on the back of a honeybee,
> so that the laser blinks could be detected (it was said) at a
> distance of 1200 meters with an 8 inch telescope. I find it almost
> unbelievable! Say, 10 microamps current into the capacitor to charge
> it up 2 volts once every 20 seconds. What happens when the bee
> changes direction? I tend to be sceptical about these things. There
> are so many practical difficulties. But what a concept.
>
> http://www.pnl.gov/news/1999/99-13.htm
> And at Pacific NW lab they use a radio backscatter tag. They think
> the bees will help the military locate unexploded landmines. Oh God
> save us!
not let in any outside critters......
Have any good ideas for this cropped up? I am curious how it all will be solved.
Could something very simple be done, like training the cat to bat at a
string and ball hanging down, that would activate a switch? Then the switch
admits entry to the door.
I know training animals is not simple but....
Sincerely
Kerry
Admin@M...
WWW server hosting [url=Http://mntnweb.com]Http://mntnweb.com[/url]
Kerry Barlow
p.o. box 21
kirkwood ny
13795
607-775-1132
This could easily be sensed and counted by the stamp to occur in a
stated amount of time and let Felix in. *)&^)^_
Leroy
Kerry Barlow wrote:
>
> I want a gadget on my robot, so only the robot will come in the door, and
> not let in any outside critters......
> Have any good ideas for this cropped up? I am curious how it all will be
solved.
> Could something very simple be done, like training the cat to bat at a
> string and ball hanging down, that would activate a switch? Then the switch
> admits entry to the door.
> I know training animals is not simple but....
> Sincerely
> Kerry
> Admin@M...
> WWW server hosting [url=Http://mntnweb.com]Http://mntnweb.com[/url]
> Kerry Barlow
> p.o. box 21
> kirkwood ny
> 13795
> 607-775-1132
>
> 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/
make a mat that acts like an electronic scales, and program it to
the weight of your cat plus or minus a little??
maybe all cats weigh about the same though, I don't have a cat
they all look alike to me... ;-)
Original Message
From: "Leroy Hall" <leroy@f...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, November 07, 2001 4:37 PM
Subject: Re: [noparse][[/noparse]basicstamps] tolltag like sensor for cat door
> I was thinking to get the Kitty to meow real loud, say three times.
> This could easily be sensed and counted by the stamp to occur in a
> stated amount of time and let Felix in. *)&^)^_
>
> Leroy
>
> Kerry Barlow wrote:
> >
> > I want a gadget on my robot, so only the robot will come in the door,
and
> > not let in any outside critters......
> > Have any good ideas for this cropped up? I am curious how it all will be
solved.
> > Could something very simple be done, like training the cat to bat at a
> > string and ball hanging down, that would activate a switch? Then the
switch
> > admits entry to the door.
> > I know training animals is not simple but....
> > Sincerely
> > Kerry
> > Admin@M...
> > WWW server hosting [url=Http://mntnweb.com]Http://mntnweb.com[/url]
> > Kerry Barlow
> > p.o. box 21
> > kirkwood ny
> > 13795
> > 607-775-1132
> >
> > 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.
> >
> >
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http://docs.yahoo.com/info/terms/
>
>
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>