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Sonar Question — Parallax Forums

Sonar Question

ArchiverArchiver Posts: 46,084
edited 2003-01-14 19:12 in General Discussion
I've been asked to build a traffic light controller for a teacher's home
(it's not a real traffic light, but must act like one). He'd like the
traffic light to operate once a car pulls up into his drive way. The
lights are 120 Vac, so I plan to use the Opto 22 as the relay for the
BS2 and to bash a 12V lighting system for power. However, first I
need to detect the presence of a car. I was thinking about using
the same sonar used in robots. Has anyone tried one of them
outside in the real world's noise? I'm concerned about false
detections.

Thanks,
Paul

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-01-13 14:25
    At 07:20 AM 1/13/03 -0700, verhap@o... wrote:
    >I've been asked to build a traffic light controller for a teacher's home
    >(it's not a real traffic light, but must act like one). He'd like the
    >traffic light to operate once a car pulls up into his drive way. The
    >lights are 120 Vac, so I plan to use the Opto 22 as the relay for the
    >BS2 and to bash a 12V lighting system for power. However, first I
    >need to detect the presence of a car. I was thinking about using
    >the same sonar used in robots. Has anyone tried one of them
    >outside in the real world's noise? I'm concerned about false
    >detections.
    >
    >Thanks,
    >Paul

    Paul -

    Personally I'd look more into break-the-beam type detectors. SONAR may be
    subject to all sorts of false triggering. The other thought is use a pressure
    sensor and an "inflated" hose like they have at gasoline filling stations to
    trigger the alarm bell.

    Hope that gives you some alternate ideas.

    Regards,

    Bruce Bates

    >
    >
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  • ArchiverArchiver Posts: 46,084
    edited 2003-01-13 14:40
    Paul,

    This web site carries some vehicle detection sensors that could be
    interfaced to a Stamp.

    http://www.homecontrols.com/dept_subcategory.html?subdept=SS03

    Rich

    Original Message
    From: verhap@o... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=UlkRDQ-6cJLG80Lu4qUJS52AiX9DHm8VBmJPIODYrKZhAUpY3P5zzvq4ptXkFRbD1FgYW8jTPoNQ7W98_iDZbQ]verhap@o...[/url
    Sent: Monday, January 13, 2003 8:21 AM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Sonar Question

    I've been asked to build a traffic light controller for a teacher's home

    (it's not a real traffic light, but must act like one). He'd like the
    traffic light to operate once a car pulls up into his drive way. The
    lights are 120 Vac, so I plan to use the Opto 22 as the relay for the
    BS2 and to bash a 12V lighting system for power. However, first I
    need to detect the presence of a car. I was thinking about using
    the same sonar used in robots. Has anyone tried one of them
    outside in the real world's noise? I'm concerned about false
    detections.

    Thanks,
    Paul

    To UNSUBSCRIBE, just send mail to:
    basicstamps-unsubscribe@yahoogroups.com
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  • ArchiverArchiver Posts: 46,084
    edited 2003-01-13 14:54
    In a message dated 1/13/2003 6:23:06 AM Pacific Standard Time,
    verhap@o... writes:

    > I've been asked to build a traffic light controller for a teacher's home
    > (it's not a real traffic light, but must act like one). He'd like the
    > traffic light to operate once a car pulls up into his drive way. The
    > lights are 120 Vac, so I plan to use the Opto 22 as the relay for the
    > BS2 and to bash a 12V lighting system for power. However, first I
    > need to detect the presence of a car. I was thinking about using
    > the same sonar used in robots. Has anyone tried one of them
    > outside in the real world's noise? I'm concerned about false
    > detections.
    >
    > Thanks,
    > Paul
    >

    You may want to "hack" a motion sensor that you can get at home depot for
    about $20. Disable the ambient light sensor (black tape).


    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-13 15:01
    Real traffic lights use a wire loop to detect large metal objects. Dont
    remember the details but it was a pretty simple thing.

    The other possibility is a pressure activated switch and inflated tube. You
    could use a garden hose with water in it, cap one end and stick some sort of
    rubber membrane over the other. Car hits the hose and the rubber baloons
    out, pushing a microswitch. Run a wire from the stamp pin to the switch then
    from the switch to ground and pull it high. Make the switch, the input goes
    low and your stamp does its thing.

    Original Message
    From: <verhap@o...>
    To: <basicstamps@yahoogroups.com>
    Sent: Monday, January 13, 2003 6:20 AM
    Subject: [noparse][[/noparse]basicstamps] Sonar Question


    > I've been asked to build a traffic light controller for a teacher's home
    > (it's not a real traffic light, but must act like one). He'd like the
    > traffic light to operate once a car pulls up into his drive way. The
    > lights are 120 Vac, so I plan to use the Opto 22 as the relay for the
    > BS2 and to bash a 12V lighting system for power. However, first I
    > need to detect the presence of a car. I was thinking about using
    > the same sonar used in robots. Has anyone tried one of them
    > outside in the real world's noise? I'm concerned about false
    > detections.
    >
    > Thanks,
    > Paul
    >
    > 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/
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-13 15:02
    > You may want to "hack" a motion sensor that you can get at home depot for
    > about $20. Disable the ambient light sensor (black tape).

    Would that detect a car? The sensors detect IR from human
    bodies as the radiation moves across two crystals. I'm not certain
    they could detect cars (by the way, that was my first idea).

    Paul
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-13 15:08
    > The other possibility is a pressure activated switch and inflated tube. You
    > could use a garden hose with water in it, cap one end and stick some sort of
    > rubber membrane over the other. Car hits the hose and the rubber baloons
    > out, pushing a microswitch. Run a wire from the stamp pin to the switch then
    > from the switch to ground and pull it high. Make the switch, the input goes
    > low and your stamp does its thing.

    A commerically available solution is preferred, since it's designed
    and tested to operate in the real world. Does anyone know of a
    commerically available pressure sensor of this design?

    Paul
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-13 15:37
    In a message dated 1/13/2003 7:05:06 AM Pacific Standard Time,
    verhap@o... writes:

    > >You may want to "hack" a motion sensor that you can get at home depot for
    > >about $20. Disable the ambient light sensor (black tape).
    >
    > Would that detect a car? The sensors detect IR from human
    > bodies as the radiation moves across two crystals. I'm not certain
    > they could detect cars (by the way, that was my first idea).
    >

    The motion sensor I have mounted on my garage comes on every time I pull into
    my driveway (at night) so guess it will detect a vehicle.

    The garden hose/membrane idea I read on an earlier posting is a cleaver and
    inexpensive pressure switch....


    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-13 15:53
    In a message dated 1/13/2003 7:38:38 AM Pacific Standard Time,
    smartdim@a... writes:

    > n a message dated 1/13/2003 7:05:06 AM Pacific Standard Time,
    > verhap@o... writes:
    >
    > >>You may want to "hack" a motion sensor that you can get at home depot for
    >
    > >>about $20. Disable the ambient light sensor (black tape).
    > >
    > >Would that detect a car? The sensors detect IR from human
    > >bodies as the radiation moves across two crystals. I'm not certain
    > >they could detect cars (by the way, that was my first idea).
    > >
    >
    > The motion sensor I have mounted on my garage comes on every time I pull
    > into
    > my driveway (at night) so guess it will detect a vehicle.
    >
    > The garden hose/membrane idea I read on an earlier posting is a cleaver and
    >
    > inexpensive pressure switch....
    >

    Try these
    <A
    HREF="www.clearstreamco.com/cscstore/autoalert.htm">www.clearstreamco.com/cscsto\
    re/autoalert.htm</A>
    www.compuwash.com/tunp_tape_switch.htm

    www.monkeysocks.com/Qstore/p000433.htm

    www.tapeswitch.com













    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-13 16:30
    Speaking of sonar ... does anyone know a sonar range finder with an
    analog output(0-5VDC) ... the rang doesn't have to be far just
    something with close proximity (a few meters).

    Eric
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-13 16:39
    http://www.digikey.com

    Look for the SonaSwitch. They have two analog versions with 8 or 10-bit
    A/D output.

    Regards,

    -Bruce
    tech@r...
    http://www.rentron.com


    Original Message
    From: <morpheus358@c...>
    To: <basicstamps@yahoogroups.com>
    Sent: Monday, January 13, 2003 9:30 AM
    Subject: [noparse][[/noparse]basicstamps] Sonar Question


    > Speaking of sonar ... does anyone know a sonar range finder with an
    > analog output(0-5VDC) ... the rang doesn't have to be far just
    > something with close proximity (a few meters).
    >
    > Eric
    >
    >
    > 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/
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-13 18:58
    There is a "Driveway Detector" motion sensor system, with separate RF
    receiver that signals an auto with a loud two-tone bong. The motion
    sensor is quite sensitive, and has a underhanging lip to prevent pets
    from setting it off. I found it at Fry's Electronics, but it is widely
    available.

    Dennis

    Original Message
    From: verhap@o... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=SRetUuHVfrMVDbTeEgVW-lD_I2odmNjQhpqNmotpg3uKGxphDjJysijVm_3nVivEM8xl7fwRqJZimAhYswoXU019PQ]verhap@o...[/url
    Sent: Monday, January 13, 2003 7:02 AM
    To: basicstamps@yahoogroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] Sonar Question


    > You may want to "hack" a motion sensor that you can get at home depot
    > for
    > about $20. Disable the ambient light sensor (black tape).

    Would that detect a car? The sensors detect IR from human
    bodies as the radiation moves across two crystals. I'm not certain
    they could detect cars (by the way, that was my first idea).

    Paul

    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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  • ArchiverArchiver Posts: 46,084
    edited 2003-01-13 22:21
    The fill switch on a washing machine is a good source for a pressure switch.
    Connect it to a piece of hose plugged at the other end -- when a tire goes
    over the hose, it raises the pressure and closes the switch.


    Original Message

    > Real traffic lights use a wire loop to detect large metal objects. Dont
    > remember the details but it was a pretty simple thing.
    >
    > The other possibility is a pressure activated switch and inflated tube.
    You
    > could use a garden hose with water in it, cap one end and stick some sort
    of
    > rubber membrane over the other. Car hits the hose and the rubber baloons
    > out, pushing a microswitch. Run a wire from the stamp pin to the switch
    then
    > from the switch to ground and pull it high. Make the switch, the input
    goes
    > low and your stamp does its thing.
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-14 00:31
    >>You may want to "hack" a motion sensor that you can get at home depot
    >>for
    >>about $20. Disable the ambient light sensor (black tape).
    >>
    >
    > Would that detect a car? The sensors detect IR from human
    > bodies as the radiation moves across two crystals. I'm not certain
    > they could detect cars (by the way, that was my first idea).

    I have tried this before and found that it will detect slow
    moving vehicles from almost head-on fairly well (probably
    detects radiator heat). However faster moving vehicles and
    those approaching from right angles are not detected very well
    at all. There is also a significant time lag (maybe 1 sec.)
    before detection in my experinces. If your interested in
    hacking a commercial PIR sensor do a google search on "game cam"
    and you'll find several very good hacks described.

    --

    Michael Burr
    Our government it seems has got a new plan...
    Seize and search the private records of every man.
    No warrants, no judges, no due process required,
    With "Homeland Security" the 4th Amendment's retired.
    "Total Information Awareness" the project is called,
    Oh would our forefathers be aghast and appalled!

    http://geocities.com/totalinformationawareness/
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-14 01:20
    Check out CIRCUIT CELLAR magazine. This month they have the winner of the
    Cypress PSoC contest. A PSoC is a programable System on a Chip. It's a MCU
    that can be configured with AD, Amplifiers, PWM, all sorts of hardware, with
    just the 28 pin chip.

    The 1st place winner is a Sonar Ranging system that uses just the PSoC chip,
    a sonar transmitter and reciever and a couple of resistors. The chip is
    available from Digikey and is like $8. The programmer is about $30. The
    software is free from Cypress.

    I've worked with the PSoC and it's pretty simple (although I haven't
    mastered the analouge parts yet).

    Check it out!

    chris in napa
    chris in napa
    Original Message
    From: <morpheus358@c...>
    To: <basicstamps@yahoogroups.com>
    Sent: Monday, January 13, 2003 8:30 AM
    Subject: [noparse][[/noparse]basicstamps] Sonar Question


    > Speaking of sonar ... does anyone know a sonar range finder with an
    > analog output(0-5VDC) ... the rang doesn't have to be far just
    > something with close proximity (a few meters).
    >
    > Eric
    >
    >
    > 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/
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-14 13:39
    Gas stations have been using an air hose activated sensor for decades!

    Original Message
    From: verhap@o... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=FfCFWVL0E9NwCMEm_EasKxqdK0V4k4_Bx0JQLs6VJ99lbHsd5c53HlrEm8i1WMav8Sc5nOher_vfuVRmUqihSQ]verhap@o...[/url
    Sent: Monday, January 13, 2003 10:04 AM
    To: basicstamps@yahoogroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] Sonar Question


    > The other possibility is a pressure activated switch and inflated tube.
    You
    > could use a garden hose with water in it, cap one end and stick some sort
    of
    > rubber membrane over the other. Car hits the hose and the rubber baloons
    > out, pushing a microswitch. Run a wire from the stamp pin to the switch
    then
    > from the switch to ground and pull it high. Make the switch, the input
    goes
    > low and your stamp does its thing.

    A commerically available solution is preferred, since it's designed
    and tested to operate in the real world. Does anyone know of a
    commerically available pressure sensor of this design?

    Paul

    To UNSUBSCRIBE, just send mail to:
    basicstamps-unsubscribe@yahoogroups.com
    from the same email address that you subscribed. Text in the Subject and
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  • ArchiverArchiver Posts: 46,084
    edited 2003-01-14 14:25
    Hi Paul you might try looking at Mier Products Inc. they have a system
    already designed to do this type of detection with out cutting driveway the
    system is call Drive-Alert Driveway Alarm System DA500. Also sold by ADI
    company. The sensor can be installed in the ground beside the driveway. I
    have purchased this system and installed it is very reliable.

    John





    >From: <verhap@o...>
    >Reply-To: basicstamps@yahoogroups.com
    >To: basicstamps@yahoogroups.com
    >Subject: [noparse][[/noparse]basicstamps] Sonar Question
    >Date: Mon, 13 Jan 2003 07:20:56 -700
    >
    >I've been asked to build a traffic light controller for a teacher's home
    >(it's not a real traffic light, but must act like one). He'd like the
    >traffic light to operate once a car pulls up into his drive way. The
    >lights are 120 Vac, so I plan to use the Opto 22 as the relay for the
    >BS2 and to bash a 12V lighting system for power. However, first I
    >need to detect the presence of a car. I was thinking about using
    >the same sonar used in robots. Has anyone tried one of them
    >outside in the real world's noise? I'm concerned about false
    >detections.
    >
    >Thanks,
    >Paul
    >
    >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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    MSN 8 with e-mail virus protection service: 2 months FREE*
    http://join.msn.com/?page=features/virus
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-14 19:12
    Another similar brand is Driveway Patrol for $24.95
    http://www.savontv.com/google/driveway-patrol.html. I have 2 of these,
    and can use either 2 sensors with one receiver, or one or both sensors
    with both receivers in different locations. The 2-tone bongs of the
    receivers are slightly different, which is also useful for
    discrimination of sensor location.

    Dennis

    Original Message
    From: John Potts [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=5PjaXMZSzC5_qipCdydLupVkDQmgkLTTXVsiSTJdNzw6OOMcOrRmOFUegWyFvDlCoJLH6uAJopjq]jp4980@h...[/url
    Sent: Tuesday, January 14, 2003 6:26 AM
    To: basicstamps@yahoogroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] Sonar Question



    Hi Paul you might try looking at Mier Products Inc. they have a system
    already designed to do this type of detection with out cutting driveway
    the
    system is call Drive-Alert Driveway Alarm System DA500. Also sold by ADI

    company. The sensor can be installed in the ground beside the driveway.
    I
    have purchased this system and installed it is very reliable.

    John





    >From: <verhap@o...>
    >Reply-To: basicstamps@yahoogroups.com
    >To: basicstamps@yahoogroups.com
    >Subject: [noparse][[/noparse]basicstamps] Sonar Question
    >Date: Mon, 13 Jan 2003 07:20:56 -700
    >
    >I've been asked to build a traffic light controller for a teacher's
    >home (it's not a real traffic light, but must act like one). He'd like

    >the traffic light to operate once a car pulls up into his drive way.
    >The lights are 120 Vac, so I plan to use the Opto 22 as the relay for
    >the BS2 and to bash a 12V lighting system for power. However, first I
    >need to detect the presence of a car. I was thinking about using the
    >same sonar used in robots. Has anyone tried one of them outside in the

    >real world's noise? I'm concerned about false detections.
    >
    >Thanks,
    >Paul
    >
    >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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    http://join.msn.com/?page=features/virus


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