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Headbot circuit for IR

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  • joshuagalloway73
    I was wondering if someone new of a link to a schematic for a head bot type design that follows an IR source. I would like to use a circuit like this for a
    Message 1 of 5 , Nov 1, 2007
      I was wondering if someone new of a link to a schematic for a head bot
      type design that follows an IR source. I would like to use a circuit
      like this for a school project instead of another uC.

      Joshua Galloway
    • Joseph Charles
      Hi Joshua, Any head design that uses IR diodes as the sensors is reacting to IR in the environment. If you want your design to follow a particular source, you
      Message 2 of 5 , Nov 2, 2007
        Hi Joshua,

        Any head design that uses IR diodes as the sensors is reacting to
        IR in the environment.

        If you want your design to follow a particular source, you will need
        to have it ignore unwanted environmental sources. You could shield
        your sensors, or you could use a modulated IR source.

        The difficulty with using modulated IR receivers as the sensors in a
        head design is that they are not sensitive to the relative distance of
        the source to the sensor. A T.V. remote works as well from 5 metres
        away from the receiver as it does from 1 metre away.

        The idea that Wilf used in his 40kHz Herbie scheme is probably your
        best bet if you want to go down that road.

        The circuit is here:
        http://tech.groups.yahoo.com/group/beam/files/wilf_nv/40kHzHerbie3.gif

        The genesis of the circuit is here:
        http://tech.groups.yahoo.com/group/beam/message/51128

        And there is more concerning a particular application, with some
        caveats, here:
        http://tech.groups.yahoo.com/group/beam/message/51742

        Feel free with any further questions.

        Cheers,

        Jo




        --- In beam@yahoogroups.com, "joshuagalloway73" <joshuagalloway73@...>
        wrote:
        >
        > I was wondering if someone new of a link to a schematic for a head bot
        > type design that follows an IR source. I would like to use a circuit
        > like this for a school project instead of another uC.
        >
        > Joshua Galloway
        >
      • joshuagalloway73
        Thank you for your help Joseph. The sources I m trying to follow are modulated--one at 2.5kHz, and another at 4kHz, both (+/-)5% square waves. I m hoping to
        Message 3 of 5 , Nov 3, 2007
          Thank you for your help Joseph. The sources I'm trying to follow are
          modulated--one at 2.5kHz, and another at 4kHz, both (+/-)5% square
          waves. I'm hoping to encode the position of the headbot to allow for
          triangulation of the two beacons and subsequently, positional feedback
          for my robot. I know I will have to build a couple of band pass
          filters for the detectors. Mostly, I was just wondering if someone had
          already done the work for me. If there is a schematic for an ir
          headbot I could just slap some active filters on, I would love to see it.

          Thanks Again,
          Joshua

          --- In beam@yahoogroups.com, "Joseph Charles" <jodicalhon@...> wrote:
          >
          > Hi Joshua,
          >
          > Any head design that uses IR diodes as the sensors is reacting to
          > IR in the environment.
          >
          > If you want your design to follow a particular source, you will need
          > to have it ignore unwanted environmental sources. You could shield
          > your sensors, or you could use a modulated IR source.
          >
          > The difficulty with using modulated IR receivers as the sensors in a
          > head design is that they are not sensitive to the relative distance of
          > the source to the sensor. A T.V. remote works as well from 5 metres
          > away from the receiver as it does from 1 metre away.
          >
          > The idea that Wilf used in his 40kHz Herbie scheme is probably your
          > best bet if you want to go down that road.
          >
          > The circuit is here:
          > http://tech.groups.yahoo.com/group/beam/files/wilf_nv/40kHzHerbie3.gif
          >
          > The genesis of the circuit is here:
          > http://tech.groups.yahoo.com/group/beam/message/51128
          >
          > And there is more concerning a particular application, with some
          > caveats, here:
          > http://tech.groups.yahoo.com/group/beam/message/51742
          >
          > Feel free with any further questions.
          >
          > Cheers,
          >
          > Jo
          >
          >
          >
          >
          > --- In beam@yahoogroups.com, "joshuagalloway73" <joshuagalloway73@>
          > wrote:
          > >
          > > I was wondering if someone new of a link to a schematic for a head bot
          > > type design that follows an IR source. I would like to use a circuit
          > > like this for a school project instead of another uC.
          > >
          > > Joshua Galloway
          > >
          >
        • Joseph Charles
          Sorry, Joshua, I don t know of any ready-made solutions. If I follow you correctly, you will have two sets of band-pass filters in your head, one tuned to each
          Message 4 of 5 , Nov 4, 2007
            Sorry, Joshua, I don't know of any ready-made solutions.

            If I follow you correctly, you will have two sets of band-pass
            filters in your head, one tuned to each frequency, and a 1 of 2 mux.
            First find the 2.kHz signal, note the heading, mux in the other
            filter, find the 4kHz signal, note the heading, and calculate your
            position.

            Sort of like having two heads, each tuned to a separate frequency.

            I still think that Wilf's idea of amplitude modulating the
            beacons is your best bet. You could try FM as an alternative.
            Whatever you use for a detector will have a minimum threshold that
            must be overcome before it triggers and, all things being equal,
            the closest sensor will trigger first and its output will have the
            highest duty cycle, thus allowing the head to home in on the source.
            I suppose the trick is keeping the trigger levels of both 'eyes' equal.

            Good luck, it sounds like a nice project.

            What will you use to encode the position of the headbot?

            Cheers,

            Jo


            --- In beam@yahoogroups.com, "joshuagalloway73" <joshuagalloway73@...>
            wrote:
            >
            > Thank you for your help Joseph. The sources I'm trying to follow
            are modulated--one at 2.5kHz, and another at 4kHz, both (+/-)5% square
            waves. I'm hoping to encode the position of the headbot to allow for
            > triangulation of the two beacons and subsequently, positional feedback
            > for my robot. I know I will have to build a couple of band pass
            > filters for the detectors. Mostly, I was just wondering if someone had
            > already done the work for me. If there is a schematic for an ir
            > headbot I could just slap some active filters on, I would love to
            see > it.
          • joshuagalloway73
            I was going to use the guts from an old computer mouse to encode the position of the head bot. ... allow for
            Message 5 of 5 , Nov 4, 2007
              I was going to use the guts from an old computer mouse to encode the
              position of the head bot.

              --- In beam@yahoogroups.com, "Joseph Charles" <jodicalhon@...> wrote:
              >
              > Sorry, Joshua, I don't know of any ready-made solutions.
              >
              > If I follow you correctly, you will have two sets of band-pass
              > filters in your head, one tuned to each frequency, and a 1 of 2 mux.
              > First find the 2.kHz signal, note the heading, mux in the other
              > filter, find the 4kHz signal, note the heading, and calculate your
              > position.
              >
              > Sort of like having two heads, each tuned to a separate frequency.
              >
              > I still think that Wilf's idea of amplitude modulating the
              > beacons is your best bet. You could try FM as an alternative.
              > Whatever you use for a detector will have a minimum threshold that
              > must be overcome before it triggers and, all things being equal,
              > the closest sensor will trigger first and its output will have the
              > highest duty cycle, thus allowing the head to home in on the source.
              > I suppose the trick is keeping the trigger levels of both 'eyes' equal.
              >
              > Good luck, it sounds like a nice project.
              >
              > What will you use to encode the position of the headbot?
              >
              > Cheers,
              >
              > Jo
              >
              >
              > --- In beam@yahoogroups.com, "joshuagalloway73" <joshuagalloway73@>
              > wrote:
              > >
              > > Thank you for your help Joseph. The sources I'm trying to follow
              > are modulated--one at 2.5kHz, and another at 4kHz, both (+/-)5% square
              > waves. I'm hoping to encode the position of the headbot to
              allow for
              > > triangulation of the two beacons and subsequently, positional feedback
              > > for my robot. I know I will have to build a couple of band pass
              > > filters for the detectors. Mostly, I was just wondering if someone had
              > > already done the work for me. If there is a schematic for an ir
              > > headbot I could just slap some active filters on, I would love to
              > see > it.
              >
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