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Need More Space !!!! — Parallax Forums

Need More Space !!!!

ArchiverArchiver Posts: 46,084
edited 2000-08-06 03:22 in General Discussion
Hello fellow stampers!!

I am trying to build a Infrared sensor that will be used with my
stamp. I am using a high output IR-LED and a phototransistor, but I
have only been able to make it work with a distance of about six
inches apart from each other. I need to extend the distance to about
five to six feet and be as econimical as possible. I am open to any
suggestions. The sensor does not need a frequency circuit, I simply
want to have a continual beam that the phototransistor can pick up
and react to a break in the beam.
I will appreciate any and all feedback from you.

Thank you,

Frank G.

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2000-08-04 05:20
    Frank:
    Have you tried lenses? You can get great improvement unless the tx/rx are
    already well-focused. Cheap reading magnifiers may work.

    Ray McArthur

    Original Message
    From: Dr. Frankenstein <fwankg@y...>
    To: <basicstamps@egroups.com>
    Sent: Thursday, August 03, 2000 11:54 PM
    Subject: [noparse][[/noparse]basicstamps] Need More Space !!!!


    > Hello fellow stampers!!
    >
    > I am trying to build a Infrared sensor that will be used with my
    > stamp. I am using a high output IR-LED and a phototransistor, but I
    > have only been able to make it work with a distance of about six
    > inches apart from each other. I need to extend the distance to about
    > five to six feet and be as econimical as possible. I am open to any
    > suggestions. The sensor does not need a frequency circuit, I simply
    > want to have a continual beam that the phototransistor can pick up
    > and react to a break in the beam.
    > I will appreciate any and all feedback from you.
  • ArchiverArchiver Posts: 46,084
    edited 2000-08-04 12:44
    Lenses are probably your best choice, but you may want to try pulsing
    the beam. Using a 555 time with about a 5% duty cycle you can pulse
    far higher current through it as long as the average current does not
    exceed the max (usually around 100mA for IR). At 5% you can push
    almost 500mA to make it 'brighter'.

    On the stamp side, you could either use a filter on the input from
    the detector or use software to detect the pulse.

    I'm not sure much further this will get you.

    Another option is to use an IR pickup from Radio shack. Pulsing the
    beam at a high frequency (see specs for the pick-up) the pickup will
    output 5V when the beam is detected. These are used in your VCR,TV,
    etc. In labs at SIU we've gone a good 30 feet transmitting data in
    this fashion.

    -Martin Hebel
    http://www.siu.edu/~imsasa/elm
    http://www.selmaware.com

    -- In basicstamps@egroups.com, "Dr. Frankenstein" <fwankg@y...> wrote:
    > Hello fellow stampers!!
    >
    > I am trying to build a Infrared sensor that will be used with my
    > stamp. I am using a high output IR-LED and a phototransistor, but
    I
    > have only been able to make it work with a distance of about six
    > inches apart from each other. I need to extend the distance to
    about
    > five to six feet and be as econimical as possible. I am open to
    any
    > suggestions. The sensor does not need a frequency circuit, I
    simply
    > want to have a continual beam that the phototransistor can pick up
    > and react to a break in the beam.
    > I will appreciate any and all feedback from you.
    >
    > Thank you,
    >
    > Frank G.
  • ArchiverArchiver Posts: 46,084
    edited 2000-08-04 16:06
    RCtime works well with IR phototransisters. A second IR can be used
    with softtware to balance for ambient light (on another pin).

    --- In basicstamps@egroups.com, "Dr. Frankenstein" <fwankg@y...>
    wrote:
    > Hello fellow stampers!!
    >
    > I am trying to build a Infrared sensor that will be used with my
    > stamp. I am using a high output IR-LED and a phototransistor, but
    I
    > have only been able to make it work with a distance of about six
    > inches apart from each other. I need to extend the distance to
    about
    > five to six feet and be as econimical as possible. I am open to
    any
    > suggestions. The sensor does not need a frequency circuit, I
    simply
    > want to have a continual beam that the phototransistor can pick up
    > and react to a break in the beam.
    > I will appreciate any and all feedback from you.
    >
    > Thank you,
    >
    > Frank G.
  • ArchiverArchiver Posts: 46,084
    edited 2000-08-04 17:15
    I have had IR. led's working at 30 feet using lenses. I had a three
    foot circle at that distance I started with a red led Key chain light
    and used a magnifying glass I was able to see the red LED light at 75
    + feet. You need to play with the distance between the light and the
    lens, I had a camera that I used to focus the IR beam and I have also
    read that a viedo camera is able to see IR.

    I ended up going to laser's with unknown distance limits ??

    good luck

    rjmca wrote:
    >
    > Frank:
    > Have you tried lenses? You can get great improvement unless the tx/rx are
    > already well-focused. Cheap reading magnifiers may work.
    >
    > Ray McArthur
    >
    >
    Original Message
    > From: Dr. Frankenstein <fwankg@y...>
    > To: <basicstamps@egroups.com>
    > Sent: Thursday, August 03, 2000 11:54 PM
    > Subject: [noparse][[/noparse]basicstamps] Need More Space !!!!
    >
    > > Hello fellow stampers!!
    > >
    > > I am trying to build a Infrared sensor that will be used with my
    > > stamp. I am using a high output IR-LED and a phototransistor, but I
    > > have only been able to make it work with a distance of about six
    > > inches apart from each other. I need to extend the distance to about
    > > five to six feet and be as econimical as possible. I am open to any
    > > suggestions. The sensor does not need a frequency circuit, I simply
    > > want to have a continual beam that the phototransistor can pick up
    > > and react to a break in the beam.
    > > I will appreciate any and all feedback from you.
  • ArchiverArchiver Posts: 46,084
    edited 2000-08-05 09:45
    --- In basicstamps@egroups.com, LarryGaminde <lgaminde@t...> wrote:
    > I have had IR. led's working at 30 feet using lenses. I had a three
    > foot circle at that distance I started with a red led Key chain
    light
    > and used a magnifying glass I was able to see the red LED light at
    75
    > + feet. You need to play with the distance between the light and the
    > lens, I had a camera that I used to focus the IR beam and I have
    also
    > read that a viedo camera is able to see IR.
    >
    > I ended up going to laser's with unknown distance limits ??
    >
    > good luck
    >
    > rjmca wrote:
    > >
    > > Frank:
    > > Have you tried lenses? You can get great improvement unless the
    tx/rx are
    > > already well-focused. Cheap reading magnifiers may work.
    > >
    > > Ray McArthur
    > >
    > >
    Original Message
    > > From: Dr. Frankenstein <fwankg@y...>
    > > To: <basicstamps@egroups.com>
    > > Sent: Thursday, August 03, 2000 11:54 PM
    > > Subject: [noparse][[/noparse]basicstamps] Need More Space !!!!
    > >
    > > > Hello fellow stampers!!
    > > >
    > > > I am trying to build a Infrared sensor that will be used with my
    > > > stamp. I am using a high output IR-LED and a phototransistor,
    but I
    > > > have only been able to make it work with a distance of about six
    > > > inches apart from each other. I need to extend the distance to
    about
    > > > five to six feet and be as econimical as possible. I am open
    to any
    > > > suggestions. The sensor does not need a frequency circuit, I
    simply
    > > > want to have a continual beam that the phototransistor can pick
    up
    > > > and react to a break in the beam.
    > > > I will appreciate any and all feedback from you.
    I want to thank all of you for the very informative feedback that I
    received. I want to eventually build a project for Halloween. I
    want to position a set of sensors(about 8-10) along a side walk. I
    want to build a skeleton that will move its head with the stamp and a
    servo. The idea is to have the skeleton move as if it were looking
    straight at the trick-or-treaters as they walk along the side walk.
    If you all have any other ideas for me I would appreciate it.

    Thanks again for all the info.

    Frank G.
  • ArchiverArchiver Posts: 46,084
    edited 2000-08-06 03:22
    At 08:45 AM 8/5/00, you wrote:

    > > > > Hello fellow stampers!!

    Hi Frank -

    > > > >
    > > > > I am trying to build a Infrared sensor that will be used with my
    > > > > stamp. I am using a high output IR-LED and a phototransistor,
    >but I
    > > > > have only been able to make it work with a distance of about six
    > > > > inches apart from each other. I need to extend the distance to
    >about
    > > > > five to six feet and be as econimical as possible. I am open
    >to any
    > > > > suggestions. The sensor does not need a frequency circuit, I
    >simply
    > > > > want to have a continual beam that the phototransistor can pick
    >up
    > > > > and react to a break in the beam.
    > > > > I will appreciate any and all feedback from you.
    >I want to thank all of you for the very informative feedback that I
    >received. I want to eventually build a project for Halloween. I
    >want to position a set of sensors(about 8-10) along a side walk. I
    >want to build a skeleton that will move its head with the stamp and a
    >servo. The idea is to have the skeleton move as if it were looking
    >straight at the trick-or-treaters as they walk along the side walk.
    >If you all have any other ideas for me I would appreciate it.

    This may be all you will need to complete your project:

    [noparse][[/noparse] http://www.wildrice.com/Halloween/Construction/Skeleton/ ]

    Have fun

    Regards,

    Bruce Bates

    >Thanks again for all the info.
    >
    >Frank G.
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