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Buried Fence Detector — Parallax Forums

Buried Fence Detector

ArchiverArchiver Posts: 46,084
edited 2003-04-08 17:42 in General Discussion
My friend has a buried fence system for keeping his dog within the yard. He
never installed it, and it has been in his garage for the past few years.
We are trying to build a mower-bot with the BS2. I found a circuit in an
old Projects book from Radio Shack that uses an Op-Amp and a Power-Amp. We
built the circuit and connected the input to an Inductor. The circuit has a
speaker, so we are able to hear "Clicks" as we move the circuit closer to
the wire loop that is connected to the signal generator.
The "Clicks" are soft when the circuit is far away from the wire loop, and
gets louder as the circuit is moved closer.

We have tried using the COUNT command to calculate the frequency, and also
tried using the RCTIME command. The frequency jumps all around the place.
We don't know the actual frequency that the signal generator is putting
through the wire loop - and placing a finger near one of the capacitors in
the circuit picks up on a radio station. There is always noise through the
speaker. I have a Tone Decoder ( but as I mentioned, we don't know the
frequency ).

When I tried the RCTIME, I put a .1 uf capacitor to +5 in series with a 5k
resistor going to ground. I had a 220 ohm resistor going from the stamp to
the midpoint junction of the capacitor and the resistor.

Does anyone have any suggestions as to how we can have the BS2 to know that
the circuit is getting close to the wire loop ?



[noparse][[/noparse]Non-text portions of this message have been removed]

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-03-21 22:23
    You may get some tips from the Robomower website --
    www.friendlyrobotics.com . I installed the Robomower perimeter wire
    around my yard 2 weeks ago, and the mower works like a charm. I haven't
    checked out the wire's signal characteristics, but the separate control
    box must be on before the mower will move at all, and the mower doesn't
    cross the wire. Pretty exciting the first time it stopped 6 inches from
    the edge of the pool. [noparse]:)[/noparse]

    Dennis

    Original Message
    From: Bryan Smith [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=ibYtpWFSrsPo2CQkMK_IrOcvUCA-P_wdW7gF6IDqDbxz1YpvJvvyNIx82p8eseFiF3zjHAos2wZHaeA]bsmith@w...[/url
    Sent: Thursday, March 20, 2003 12:27 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Buried Fence Detector


    My friend has a buried fence system for keeping his dog within the yard.
    He never installed it, and it has been in his garage for the past few
    years. We are trying to build a mower-bot with the BS2. I found a
    circuit in an old Projects book from Radio Shack that uses an Op-Amp and
    a Power-Amp. We built the circuit and connected the input to an
    Inductor. The circuit has a speaker, so we are able to hear "Clicks" as
    we move the circuit closer to the wire loop that is connected to the
    signal generator. The "Clicks" are soft when the circuit is far away
    from the wire loop, and gets louder as the circuit is moved closer.

    We have tried using the COUNT command to calculate the frequency, and
    also tried using the RCTIME command. The frequency jumps all around the
    place. We don't know the actual frequency that the signal generator is
    putting through the wire loop - and placing a finger near one of the
    capacitors in the circuit picks up on a radio station. There is always
    noise through the speaker. I have a Tone Decoder ( but as I mentioned,
    we don't know the frequency ).

    When I tried the RCTIME, I put a .1 uf capacitor to +5 in series with a
    5k resistor going to ground. I had a 220 ohm resistor going from the
    stamp to the midpoint junction of the capacitor and the resistor.

    Does anyone have any suggestions as to how we can have the BS2 to know
    that the circuit is getting close to the wire loop ?



    [noparse][[/noparse]Non-text portions of this message have been removed]


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  • ArchiverArchiver Posts: 46,084
    edited 2003-04-08 11:53
    In a message dated 3/20/03 2:29:34 PM Mountain Daylight Time,
    bsmith@w... writes:


    > My friend has a buried fence system for keeping his dog within the yard. He
    > never installed it, and it has been in his garage for the past few years.
    > We are trying to build a mower-bot with the BS2. I found a circuit in an
    > old Projects book from Radio Shack that uses an Op-Amp and a Power-Amp. We
    > built the circuit and connected the input to an Inductor. The circuit has
    > a
    > speaker, so we are able to hear "Clicks" as we move the circuit closer to
    > the wire loop that is connected to the signal generator.
    > The "Clicks" are soft when the circuit is far away from the wire loop, and
    > gets louder as the circuit is moved closer.
    >
    > We have tried using the COUNT command to calculate the frequency, and also
    > tried using the RCTIME command. The frequency jumps all around the place.
    > We don't know the actual frequency that the signal generator is putting
    > through the wire loop - and placing a finger near one of the capacitors in
    > the circuit picks up on a radio station. There is always noise through the
    > speaker. I have a Tone Decoder ( but as I mentioned, we don't know the
    > frequency ).
    >
    > When I tried the RCTIME, I put a .1 uf capacitor to +5 in series with a 5k
    > resistor going to ground. I had a 220 ohm resistor going from the stamp to
    > the midpoint junction of the capacitor and the resistor.
    >
    > Does anyone have any suggestions as to how we can have the BS2 to know that
    > the circuit is getting close to the wire loop ?
    >

    Just curious if you figured out a way to detect the loop?

    Tim


    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2003-04-08 15:27
    Yes, we can detect it. I have several Radio Shack project books by Mims.
    Neither of of are very good on the electronics side of things, but we have
    An Inductor and Capacitor in series that feeds into an Op-Amp that feeds
    Into a Power-Amp. We think the frequency of the dog fence is 10 kHz, but
    We are not for sure. We have setup another circuit using a 567 tone
    decoder.
    We are hoping to use it to hone in on the signal and ignore the radio
    reception.

    We have experimented with a 555 to generate a 1 kHz signal and feed that
    into the
    567 tone decoder. The output of the tone decoder, we sent to our BS2 and
    made use
    Of the COUNT command; and read the value of IN1. We then placed a POT on
    the 555
    and varied the frequency. The IN1 goes hi/low depending on the frequency.

    We are getting a range of maybe 8 inches so far. Using a speaker, we can
    hear the
    Signal up to 3 feet away We want to detect the fence up to 2 feet.

    Our detector circuit as I said before has an Inductor and a Capacitor that
    forms
    A filter. If we knew for sure the frequency of the wire fence - maybe we
    could
    Get better performance out of the circuit.


    Original Message
    From: Trkeenan@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=r9FX3BBtrDAACevSc112oH01ZI5dBaCB0KaQr5Pypbpvfeh2V3AlViDlitBXFQemwFtkrGvf5QE]Trkeenan@a...[/url
    Sent: Tuesday, April 08, 2003 5:53 AM
    To: basicstamps@yahoogroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] Buried Fence Detector


    In a message dated 3/20/03 2:29:34 PM Mountain Daylight Time,
    bsmith@w... writes:


    > My friend has a buried fence system for keeping his dog within the
    > yard. He never installed it, and it has been in his garage for the
    > past few years. We are trying to build a mower-bot with the BS2. I
    > found a circuit in an old Projects book from Radio Shack that uses an
    > Op-Amp and a Power-Amp. We built the circuit and connected the input
    > to an Inductor. The circuit has a speaker, so we are able to hear
    > "Clicks" as we move the circuit closer to the wire loop that is
    > connected to the signal generator. The "Clicks" are soft when the
    > circuit is far away from the wire loop, and gets louder as the circuit
    > is moved closer.
    >
    > We have tried using the COUNT command to calculate the frequency, and
    > also tried using the RCTIME command. The frequency jumps all around
    > the place. We don't know the actual frequency that the signal
    > generator is putting through the wire loop - and placing a finger near
    > one of the capacitors in the circuit picks up on a radio station.
    > There is always noise through the speaker. I have a Tone Decoder (
    > but as I mentioned, we don't know the frequency ).
    >
    > When I tried the RCTIME, I put a .1 uf capacitor to +5 in series with
    > a 5k resistor going to ground. I had a 220 ohm resistor going from
    > the stamp to the midpoint junction of the capacitor and the resistor.
    >
    > Does anyone have any suggestions as to how we can have the BS2 to know
    > that the circuit is getting close to the wire loop ?
    >

    Just curious if you figured out a way to detect the loop?

    Tim


    [noparse][[/noparse]Non-text portions of this message have been removed]


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  • ArchiverArchiver Posts: 46,084
    edited 2003-04-08 16:08
    The Petsafe brand radio fence uses a 10.65KHz signal. This may give you a
    ballpark range for your own fence brand, whatever it is.
    I too am extremly interested in this topic. I have tried going to the Mux
    lawnmower website many times in the past, and either cannot get on the site,
    or the english documents are corrupted, or not even there. Maybe you could
    just buy another dog collar on ebay for your fence, and hack the collar. I
    was thinking of doing that since my electronic skills are not the best
    either. Of course the price factor is always an issue, for me as well. My
    Dog collars are potted, but I was hoping I could get at the circut somehow.
    Another idea I had was using an external microphone pickup near the collar.
    I could listen for the beep tone the collar makes as it is in the detection
    mode.
    Please keep us informed of your progress.
    -Kerry

    At 09:27 AM 4/8/03 -0500, you wrote:
    >Yes, we can detect it. I have several Radio Shack project books by Mims.
    >Neither of of are very good on the electronics side of things, but we have
    >An Inductor and Capacitor in series that feeds into an Op-Amp that feeds
    >Into a Power-Amp. We think the frequency of the dog fence is 10 kHz, but
    >We are not for sure. We have setup another circuit using a 567 tone
    >decoder.
    >We are hoping to use it to hone in on the signal and ignore the radio
    >reception.
    >
    >We have experimented with a 555 to generate a 1 kHz signal and feed that
    >into the
    >567 tone decoder. The output of the tone decoder, we sent to our BS2 and
    >made use
    >Of the COUNT command; and read the value of IN1. We then placed a POT on
    >the 555
    >and varied the frequency. The IN1 goes hi/low depending on the frequency.
    >
    >We are getting a range of maybe 8 inches so far. Using a speaker, we can
    >hear the
    >Signal up to 3 feet away We want to detect the fence up to 2 feet.
    >
    >Our detector circuit as I said before has an Inductor and a Capacitor that
    >forms
    >A filter. If we knew for sure the frequency of the wire fence - maybe we
    >could
    >Get better performance out of the circuit.
    >
    >
    >
    Original Message
    >From: Trkeenan@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=eWjrIoZdTHUfD_FWN81ZaNPQiBYEeOnskZxWruj3nqJeWpYY8sPD0Qvd00Kc2hVKkzra7MKGRA_2DQ]Trkeenan@a...[/url
    >Sent: Tuesday, April 08, 2003 5:53 AM
    >To: basicstamps@yahoogroups.com
    >Subject: Re: [noparse][[/noparse]basicstamps] Buried Fence Detector
    >
    >
    >In a message dated 3/20/03 2:29:34 PM Mountain Daylight Time,
    >bsmith@w... writes:
    >
    >
    >> My friend has a buried fence system for keeping his dog within the
    >> yard. He never installed it, and it has been in his garage for the
    >> past few years. We are trying to build a mower-bot with the BS2. I
    >> found a circuit in an old Projects book from Radio Shack that uses an
    >> Op-Amp and a Power-Amp. We built the circuit and connected the input
    >> to an Inductor. The circuit has a speaker, so we are able to hear
    >> "Clicks" as we move the circuit closer to the wire loop that is
    >> connected to the signal generator. The "Clicks" are soft when the
    >> circuit is far away from the wire loop, and gets louder as the circuit
    >> is moved closer.
    >>
    >> We have tried using the COUNT command to calculate the frequency, and
    >> also tried using the RCTIME command. The frequency jumps all around
    >> the place. We don't know the actual frequency that the signal
    >> generator is putting through the wire loop - and placing a finger near
    >> one of the capacitors in the circuit picks up on a radio station.
    >> There is always noise through the speaker. I have a Tone Decoder (
    >> but as I mentioned, we don't know the frequency ).
    >>
    >> When I tried the RCTIME, I put a .1 uf capacitor to +5 in series with
    >> a 5k resistor going to ground. I had a 220 ohm resistor going from
    >> the stamp to the midpoint junction of the capacitor and the resistor.
    >>
    >> Does anyone have any suggestions as to how we can have the BS2 to know
    >> that the circuit is getting close to the wire loop ?
    >>
    >
    >Just curious if you figured out a way to detect the loop?
    >
    >Tim
    >
    >
    >[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/
    >
    >
    >
    Very respectfully, your obedient servant.
    Kerry
    Admin@M...
    WWW server hosting [url=Http://mntnweb.com]Http://mntnweb.com[/url]
    Kerry Barlow
    p.o. box 21
    kirkwood ny
    13795
    607-775-1575
  • ArchiverArchiver Posts: 46,084
    edited 2003-04-08 17:42
    I have visited the MUX site many times ( http://www.lls.se/~mux/micro.html )
    He gives schematics of his buried wire sensors. We will keep you posted as
    to our progress.

    Original Message
    From: Kerry Barlow [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=W7nZR_QApdAc4KvaMEdiWGigL5N_Z20NCe0M5KIp7JzHGkKxgVf7FAOfyUGiiKFrHzE_ICw_hc8]admin@m...[/url
    Sent: Tuesday, April 08, 2003 10:08 AM
    To: basicstamps@yahoogroups.com
    Subject: RE: [noparse][[/noparse]basicstamps] Buried Fence Detector


    The Petsafe brand radio fence uses a 10.65KHz signal. This may give you a
    ballpark range for your own fence brand, whatever it is. I too am extremly
    interested in this topic. I have tried going to the Mux lawnmower website
    many times in the past, and either cannot get on the site, or the english
    documents are corrupted, or not even there. Maybe you could just buy another
    dog collar on ebay for your fence, and hack the collar. I was thinking of
    doing that since my electronic skills are not the best either. Of course the
    price factor is always an issue, for me as well. My Dog collars are potted,
    but I was hoping I could get at the circut somehow. Another idea I had was
    using an external microphone pickup near the collar. I could listen for the
    beep tone the collar makes as it is in the detection mode. Please keep us
    informed of your progress. -Kerry

    At 09:27 AM 4/8/03 -0500, you wrote:
    >Yes, we can detect it. I have several Radio Shack project books by
    >Mims. Neither of of are very good on the electronics side of things,
    >but we have An Inductor and Capacitor in series that feeds into an
    >Op-Amp that feeds Into a Power-Amp. We think the frequency of the dog
    >fence is 10 kHz, but We are not for sure. We have setup another
    >circuit using a 567 tone decoder. We are hoping to use it to hone in on
    >the signal and ignore the radio reception.
    >
    >We have experimented with a 555 to generate a 1 kHz signal and feed
    >that into the 567 tone decoder. The output of the tone decoder, we
    >sent to our BS2 and made use
    >Of the COUNT command; and read the value of IN1. We then placed a POT on
    >the 555
    >and varied the frequency. The IN1 goes hi/low depending on the frequency.
    >
    >We are getting a range of maybe 8 inches so far. Using a speaker, we
    >can hear the Signal up to 3 feet away We want to detect the fence up
    >to 2 feet.
    >
    >Our detector circuit as I said before has an Inductor and a Capacitor
    >that forms A filter. If we knew for sure the frequency of the wire
    >fence - maybe we could
    >Get better performance out of the circuit.
    >
    >
    >
    Original Message
    >From: Trkeenan@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=jRmpffyWP7quo9CmzZed3S2SU9XaA6v87jR3NJOgvIwm3aVSwhYIS7W46pnzp0eLmYKZETVGXjYD6Q]Trkeenan@a...[/url
    >Sent: Tuesday, April 08, 2003 5:53 AM
    >To: basicstamps@yahoogroups.com
    >Subject: Re: [noparse][[/noparse]basicstamps] Buried Fence Detector
    >
    >
    >In a message dated 3/20/03 2:29:34 PM Mountain Daylight Time,
    >bsmith@w... writes:
    >
    >
    >> My friend has a buried fence system for keeping his dog within the
    >> yard. He never installed it, and it has been in his garage for the
    >> past few years. We are trying to build a mower-bot with the BS2. I
    >> found a circuit in an old Projects book from Radio Shack that uses an
    >> Op-Amp and a Power-Amp. We built the circuit and connected the input
    >> to an Inductor. The circuit has a speaker, so we are able to hear
    >> "Clicks" as we move the circuit closer to the wire loop that is
    >> connected to the signal generator. The "Clicks" are soft when the
    >> circuit is far away from the wire loop, and gets louder as the circuit
    >> is moved closer.
    >>
    >> We have tried using the COUNT command to calculate the frequency, and
    >> also tried using the RCTIME command. The frequency jumps all around
    >> the place. We don't know the actual frequency that the signal
    >> generator is putting through the wire loop - and placing a finger near
    >> one of the capacitors in the circuit picks up on a radio station.
    >> There is always noise through the speaker. I have a Tone Decoder (
    >> but as I mentioned, we don't know the frequency ).
    >>
    >> When I tried the RCTIME, I put a .1 uf capacitor to +5 in series with
    >> a 5k resistor going to ground. I had a 220 ohm resistor going from
    >> the stamp to the midpoint junction of the capacitor and the resistor.
    >>
    >> Does anyone have any suggestions as to how we can have the BS2 to
    >> know
    >> that the circuit is getting close to the wire loop ?
    >>
    >
    >Just curious if you figured out a way to detect the loop?
    >
    >Tim
    >
    >
    >[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.
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    >
    >
    >To UNSUBSCRIBE, just send mail to:
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    >and
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    >
    >
    >Your use of Yahoo! Groups is subject to
    >http://docs.yahoo.com/info/terms/
    >
    >
    >
    Very respectfully, your obedient servant.
    Kerry
    Admin@M...
    WWW server hosting [url=Http://mntnweb.com]Http://mntnweb.com[/url]
    Kerry Barlow
    p.o. box 21
    kirkwood ny
    13795
    607-775-1575




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