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Re: Visitor irritator

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  • wilf_nv
    The IR receivers are basically digital not analog output. However the 40KHzHERBIE3 circuit uses a special technique to determine which of the two receivers is
    Message 1 of 10 , Nov 23, 2005
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      The IR receivers are basically digital not analog output. However the
      40KHzHERBIE3 circuit uses a special technique to determine which of
      the two receivers is detecting higher reflected IR light. This is
      done by ramping the 40kHz (or38KHz) IR transmitter current from 0-
      100% brightness. Since each receiver requires a minimum level of IR
      before it turns on, the output goes active at some point on the
      ramping brightness. Since both receivers are exposed to the reflected
      light, the receiver which detects the higher reflected IR, will turn
      on before the other receiver. If the ramping waveform is repeated at
      say 100Hz, then each receiver will have a pulsed output whose width
      is proportional to the received reflected IR. The difference in width
      can be used directly in some case or by integrating these pulses,
      each receiver circuit can generate an analog signal between 0-5V that
      is proportional to the received IR level.

      Having said that, you cannot stack two of these Herbie receiver
      circuit in series like a couple of photodiodes in a photo bridge.
      But you can connect the two analog signals to a couple of comparators
      or opamps and use the difference between the opamp output levels to
      drive a head left or right.

      If you want to dirctly detect the reflected IR light then use a
      TSL250 and high pass filter (AC couple) the output to reject ambient
      IR light. The TSL250 application note has more details.

      wilf


      --- In beam@yahoogroups.com, "firnagzen" <slung@s...> wrote:
      >
      > The two upper recievers are basically replacements for regular left
      > and right light sensors, so that they recieve the reflected IR
      light
      > instead of regular light.
      >
      > The reciever at the bottom essentially detects the distance (those
      > recievers ARE analog output, right?) and the trimpot reduces the
      > level a bit. One of those two transistors in the distance
      adjustment
      > will turn on when the distance is at a certain level. (So that the
      > flasher and clicker part fo the circuit don't activate when the bot
      > is staring at the wall)
      >
      >
      >
      > --- In beam@yahoogroups.com, Joseph Charles <jodicalhon@y...> wrote:
      > >
      > >
      > > The V+ pin of the middle receiver is connected to the B input
      of
      > the 139. Its only connection to Vcc is via diodes D3 and D4 and a
      > 100k resistor, which I think will not allow it to operate.
      > >
      > > The 139 enable pin relies on a nice, clean low output from the
      > middle receiver.
      > >
      > > If the upper receiver triggers, its output will pulse low,
      > reverse biasing D3 and D4 and the V+ pin of the middle receiver
      will
      > float, as will input B and, via the 100k and 220k resistors, the
      > enable pin.
      > >
      > > I'm not sure what each receiver is supposed to do, and I'm not
      > sure about the purpose of the distance adjustment. Perhaps you
      could
      > give us your take on the circuit. Sorry I haven't had time to
      follow
      > your idea more closely, but I think you need to look at the
      > connections I've mentioned.
      > >
      > > All for now. Its very late here, so please forgive any
      > misreadings.
      > >
      > > Jo C
      > >
      > >
      > > firnagzen <slung@s...> wrote: Formerly "Using GP2D12 in
      a
      > headbot?"
      > >
      > > Well, I've been discussing with mycroft2152 through e-mail, and
      > this is
      > > how the project currently stands.
      > > http://www.maj.com/gallery/nuts-about-
      > > bionicle/BEAM/visitor_irritator.jpg
      > >
      > > Can someone check if the circuitry is correct, and help me to
      > fill in
      > > the blanks? (There's a couple of parts not figured out yet.)
      > Credit
      > > goes to Wilf Righter and Frans Storms for the base circuits.
      > >
      > >
      > >
      > >
      > >
      > >
      > > SPONSORED LINKS
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    • firnagzen
      Hmmmmm. So how CAN the 40kHz herbie recievers be applied to the circuit? Or do I have to change it completely? If so, how?Also, it seems that I would have to
      Message 2 of 10 , Nov 23, 2005
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        Hmmmmm. So how CAN the 40kHz herbie recievers be applied to the
        circuit? Or do I have to change it completely? If so, how?Also, it
        seems that I would have to change the distance detector: Please
        enlighten me as to how.

        --- In beam@yahoogroups.com, "wilf_nv" <wrigter@d...> wrote:
        >
        >
        >
        > The IR receivers are basically digital not analog output. However
        the
        > 40KHzHERBIE3 circuit uses a special technique to determine which of
        > the two receivers is detecting higher reflected IR light. This is
        > done by ramping the 40kHz (or38KHz) IR transmitter current from 0-
        > 100% brightness. Since each receiver requires a minimum level of IR
        > before it turns on, the output goes active at some point on the
        > ramping brightness. Since both receivers are exposed to the
        reflected
        > light, the receiver which detects the higher reflected IR, will
        turn
        > on before the other receiver. If the ramping waveform is repeated
        at
        > say 100Hz, then each receiver will have a pulsed output whose width
        > is proportional to the received reflected IR. The difference in
        width
        > can be used directly in some case or by integrating these pulses,
        > each receiver circuit can generate an analog signal between 0-5V
        that
        > is proportional to the received IR level.
        >
        > Having said that, you cannot stack two of these Herbie receiver
        > circuit in series like a couple of photodiodes in a photo bridge.
        > But you can connect the two analog signals to a couple of
        comparators
        > or opamps and use the difference between the opamp output levels to
        > drive a head left or right.
        >
        > If you want to dirctly detect the reflected IR light then use a
        > TSL250 and high pass filter (AC couple) the output to reject
        ambient
        > IR light. The TSL250 application note has more details.
        >
        > wilf
        >
        >
        > --- In beam@yahoogroups.com, "firnagzen" <slung@s...> wrote:
        > >
        > > The two upper recievers are basically replacements for regular
        left
        > > and right light sensors, so that they recieve the reflected IR
        > light
        > > instead of regular light.
        > >
        > > The reciever at the bottom essentially detects the distance
        (those
        > > recievers ARE analog output, right?) and the trimpot reduces the
        > > level a bit. One of those two transistors in the distance
        > adjustment
        > > will turn on when the distance is at a certain level. (So that
        the
        > > flasher and clicker part fo the circuit don't activate when the
        bot
        > > is staring at the wall)
        > >
        > >
        > >
        > > --- In beam@yahoogroups.com, Joseph Charles <jodicalhon@y...>
        wrote:
        > > >
        > > >
        > > > The V+ pin of the middle receiver is connected to the B input
        > of
        > > the 139. Its only connection to Vcc is via diodes D3 and D4 and
        a
        > > 100k resistor, which I think will not allow it to operate.
        > > >
        > > > The 139 enable pin relies on a nice, clean low output from
        the
        > > middle receiver.
        > > >
        > > > If the upper receiver triggers, its output will pulse low,
        > > reverse biasing D3 and D4 and the V+ pin of the middle receiver
        > will
        > > float, as will input B and, via the 100k and 220k resistors, the
        > > enable pin.
        > > >
        > > > I'm not sure what each receiver is supposed to do, and I'm
        not
        > > sure about the purpose of the distance adjustment. Perhaps you
        > could
        > > give us your take on the circuit. Sorry I haven't had time to
        > follow
        > > your idea more closely, but I think you need to look at the
        > > connections I've mentioned.
        > > >
        > > > All for now. Its very late here, so please forgive any
        > > misreadings.
        > > >
        > > > Jo C
        > > >
        > > >
        > > > firnagzen <slung@s...> wrote: Formerly "Using GP2D12
        in
        > a
        > > headbot?"
        > > >
        > > > Well, I've been discussing with mycroft2152 through e-mail,
        and
        > > this is
        > > > how the project currently stands.
        > > > http://www.maj.com/gallery/nuts-about-
        > > > bionicle/BEAM/visitor_irritator.jpg
        > > >
        > > > Can someone check if the circuitry is correct, and help me to
        > > fill in
        > > > the blanks? (There's a couple of parts not figured out yet.)
        > > Credit
        > > > goes to Wilf Righter and Frans Storms for the base circuits.
        > > >
        > > >
        > > >
        > > >
        > > >
        > > >
        > > > SPONSORED LINKS
        > > >
        Computer
        > > science distance
        education
        > > Computer science course
        > > Computer science
        > >
        >
        school
        > > Computer science
        > > degree Computer science
        > and
        > > education Computer
        science
        > >
        >
        education
        > >
        > > >
        > > > ---------------------------------
        > > > YAHOO! GROUPS LINKS
        > > >
        > > >
        > > > Visit your group "beam" on the web.
        > > >
        > > > To unsubscribe from this group, send an email to:
        > > > beam-unsubscribe@yahoogroups.com
        > > >
        > > > Your use of Yahoo! Groups is subject to the Yahoo! Terms of
        > > Service.
        > > >
        > > >
        > > > ---------------------------------
        > > >
        > > >
        > > >
        > > >
        > > >
        > > >
        > > > ---------------------------------
        > > > Do you Yahoo!?
        > > > Find a local business fast with Yahoo! Local Search
        > > >
        > >
        >
      • firnagzen
        I ve been pondering this problem for some time now. I think I may have come up with a solution: I use the LB1630 head circuit. Wilf, one of the IR sensors will
        Message 3 of 10 , Nov 28, 2005
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          I've been pondering this problem for some time now. I think I may
          have come up with a solution: I use the LB1630 head circuit. Wilf,
          one of the IR sensors will trigger before the other, right? Thus,
          whichever IR sensor triggers first, which is therefore close to the
          nearest object, will cause the head to turn towards that object until
          the other one triggers, thereby shutting down the circuit, right?

          Also, for the lock on, I tie an inverter with a smallish cap to the
          two output lines of the LB1630, and when both go low, the inverters'
          output goes high, and I can use this to run the lock on circuit.

          This would work, right? But I still need help: How can I sense the
          distance from the object to the robot? (I only want the circuit to
          lock on when the object is below a certain distance from the robot.)

          --- In beam@yahoogroups.com, "firnagzen" <slung@s...> wrote:
          >
          > Hmmmmm. So how CAN the 40kHz herbie recievers be applied to the
          > circuit? Or do I have to change it completely? If so, how?Also, it
          > seems that I would have to change the distance detector: Please
          > enlighten me as to how.
          >
          > --- In beam@yahoogroups.com, "wilf_nv" <wrigter@d...> wrote:
          > >
          > >
          > >
          > > The IR receivers are basically digital not analog output. However
          > the
          > > 40KHzHERBIE3 circuit uses a special technique to determine which
          of
          > > the two receivers is detecting higher reflected IR light. This is
          > > done by ramping the 40kHz (or38KHz) IR transmitter current from 0-
          > > 100% brightness. Since each receiver requires a minimum level of
          IR
          > > before it turns on, the output goes active at some point on the
          > > ramping brightness. Since both receivers are exposed to the
          > reflected
          > > light, the receiver which detects the higher reflected IR, will
          > turn
          > > on before the other receiver. If the ramping waveform is
          repeated
          > at
          > > say 100Hz, then each receiver will have a pulsed output whose
          width
          > > is proportional to the received reflected IR. The difference in
          > width
          > > can be used directly in some case or by integrating these pulses,
          > > each receiver circuit can generate an analog signal between 0-5V
          > that
          > > is proportional to the received IR level.
          > >
          > > Having said that, you cannot stack two of these Herbie receiver
          > > circuit in series like a couple of photodiodes in a photo bridge.
          > > But you can connect the two analog signals to a couple of
          > comparators
          > > or opamps and use the difference between the opamp output levels
          to
          > > drive a head left or right.
          > >
          > > If you want to dirctly detect the reflected IR light then use a
          > > TSL250 and high pass filter (AC couple) the output to reject
          > ambient
          > > IR light. The TSL250 application note has more details.
          > >
          > > wilf
          > >
          > >
          > > --- In beam@yahoogroups.com, "firnagzen" <slung@s...> wrote:
          > > >
          > > > The two upper recievers are basically replacements for regular
          > left
          > > > and right light sensors, so that they recieve the reflected IR
          > > light
          > > > instead of regular light.
          > > >
          > > > The reciever at the bottom essentially detects the distance
          > (those
          > > > recievers ARE analog output, right?) and the trimpot reduces
          the
          > > > level a bit. One of those two transistors in the distance
          > > adjustment
          > > > will turn on when the distance is at a certain level. (So that
          > the
          > > > flasher and clicker part fo the circuit don't activate when the
          > bot
          > > > is staring at the wall)
          > > >
          > > >
          > > >
          > > > --- In beam@yahoogroups.com, Joseph Charles <jodicalhon@y...>
          > wrote:
          > > > >
          > > > >
          > > > > The V+ pin of the middle receiver is connected to the B
          input
          > > of
          > > > the 139. Its only connection to Vcc is via diodes D3 and D4
          and
          > a
          > > > 100k resistor, which I think will not allow it to operate.
          > > > >
          > > > > The 139 enable pin relies on a nice, clean low output from
          > the
          > > > middle receiver.
          > > > >
          > > > > If the upper receiver triggers, its output will pulse low,
          > > > reverse biasing D3 and D4 and the V+ pin of the middle
          receiver
          > > will
          > > > float, as will input B and, via the 100k and 220k resistors,
          the
          > > > enable pin.
          > > > >
          > > > > I'm not sure what each receiver is supposed to do, and I'm
          > not
          > > > sure about the purpose of the distance adjustment. Perhaps you
          > > could
          > > > give us your take on the circuit. Sorry I haven't had time to
          > > follow
          > > > your idea more closely, but I think you need to look at the
          > > > connections I've mentioned.
          > > > >
          > > > > All for now. Its very late here, so please forgive any
          > > > misreadings.
          > > > >
          > > > > Jo C
          > > > >
          > > > >
          > > > > firnagzen <slung@s...> wrote: Formerly "Using GP2D12
          > in
          > > a
          > > > headbot?"
          > > > >
          > > > > Well, I've been discussing with mycroft2152 through e-mail,
          > and
          > > > this is
          > > > > how the project currently stands.
          > > > > http://www.maj.com/gallery/nuts-about-
          > > > > bionicle/BEAM/visitor_irritator.jpg
          > > > >
          > > > > Can someone check if the circuitry is correct, and help me
          to
          > > > fill in
          > > > > the blanks? (There's a couple of parts not figured out
          yet.)
          > > > Credit
          > > > > goes to Wilf Righter and Frans Storms for the base circuits.
          > > > >
          > > > >
          > > > >
          > > > >
          > > > >
          > > > >
          > > > > SPONSORED LINKS
          > > > >
          > Computer
          > > > science distance
          > education
          > > > Computer science
          course
          > > > Computer science
          > > >
          > >
          >
          school
          > > > Computer science
          > > > degree Computer
          science
          > > and
          > > > education Computer
          > science
          > > >
          > >
          >
          education
          > > >
          > > > >
          > > > > ---------------------------------
          > > > > YAHOO! GROUPS LINKS
          > > > >
          > > > >
          > > > > Visit your group "beam" on the web.
          > > > >
          > > > > To unsubscribe from this group, send an email to:
          > > > > beam-unsubscribe@yahoogroups.com
          > > > >
          > > > > Your use of Yahoo! Groups is subject to the Yahoo! Terms
          of
          > > > Service.
          > > > >
          > > > >
          > > > > ---------------------------------
          > > > >
          > > > >
          > > > >
          > > > >
          > > > >
          > > > >
          > > > > ---------------------------------
          > > > > Do you Yahoo!?
          > > > > Find a local business fast with Yahoo! Local Search
          > > > >
          > > >
          > >
          >
        • Wilf Rigter
          I have tested this distance measurement circuit using the ramping IR transmitter pulses with a single PNA4602 and it works very well in moderately light to
          Message 4 of 10 , Nov 28, 2005
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            I have tested this distance measurement circuit using the ramping IR transmitter pulses with a single PNA4602 and it works very well in moderately light to dark ambient conditions. The average IR LED current is about 50ma and the 38kHz carrier pulse width has not been optimized. The sawtooth modulation frequency is about 100Hz. By filtering the receiver output with a simple RC filter (10Hz), I get an analog output that changes from 5V and 0V when the distance to the reflecting object changes from 1.5m to 0.2m.
             
            Since the range scales with LED brightness, adding 2 LEDs in series or or increasing peak LED currents to 100mA, it should be possible to increase the detection range to greater than 2m. 
             
            Rather then using the difference in receiver output pulse width, I suggest using the filtered analog outputs. 
             
            Connecting the filtered output of two IR receivers to the (+) and (-) inputs of a comparator would generate a high or low comparator output depending on which receiver detected the stronger (nearer) reflected IR signal. When the two signals are balanced the comparator output would oscillate.  A second comparator can be used with a set point and diode OR'd inputs to determine if either of the reflections are strong enough to indicate the object is within some minimum distance of the sensors.  The outputs of the comparators can be connected to a h-bridge motor driver to enable the motor driver and track objects when they are within a certain distance of the sensors.  
             
            Note that in this context the term "lock'd on" means that equal reflections indicate that the object is centered between the detectors and the head motor is pointing toward the object while rapidly shaking  back and forth ( so rapid as to be invisible or can simply stop using a Power Smart circuit). When the object changes position, the head circuit turns the motor in one or the other direction to "track" the object. 
             
            wilf
             
             
             
            ----- Original Message -----
            From: firnagzen
            Sent: Monday, November 28, 2005 7:28 PM
            Subject: [beam] Re: Visitor irritator

            I've been pondering this problem for some time now. I think I may
            have come up with a solution: I use the LB1630 head circuit. Wilf,
            one of the IR sensors will trigger before the other, right? Thus,
            whichever IR sensor triggers first, which is therefore close to the
            nearest object, will cause the head to turn towards that object until
            the other one triggers, thereby shutting down the circuit, right?

            Also, for the lock on, I tie an inverter with a smallish cap to the
            two output lines of the LB1630, and when both go low, the inverters'
            output goes high, and I can use this to run the lock on circuit.

            This would work, right? But I still need help: How can I sense the
            distance from the object to the robot? (I only want the circuit to
            lock on when the object is below a certain distance from the robot.)

            --- In beam@yahoogroups.com, "firnagzen" <slung@s...> wrote:
            >
            > Hmmmmm. So how CAN the 40kHz herbie recievers be applied to the
            > circuit? Or do I have to change it completely? If so, how?Also, it
            > seems that I would have to change the distance detector: Please
            > enlighten me as to how.
            >
            > --- In beam@yahoogroups.com, "wilf_nv" <wrigter@d...> wrote:
            > >
            > >
            > >
            > > The IR receivers are basically digital not analog output. However
            > the
            > > 40KHzHERBIE3 circuit uses a special technique to determine which
            of
            > > the two receivers is detecting higher reflected IR light. This is
            > > done by ramping the 40kHz (or38KHz) IR transmitter current from 0-
            > > 100% brightness. Since each receiver requires a minimum level of
            IR
            > > before it turns on, the output goes active at some point on the
            > > ramping brightness. Since both receivers are exposed to the
            > reflected
            > > light, the receiver which detects the higher reflected IR, will
            > turn
            > > on before the other receiver.  If the ramping waveform is
            repeated
            > at
            > > say 100Hz, then each receiver will have a pulsed output whose
            width
            > > is proportional to the received reflected IR. The difference in
            > width
            > > can be used directly in some case or by integrating these pulses,
            > > each receiver circuit can generate an analog signal between 0-5V
            > that
            > > is proportional to the received IR level.
            > >
            > > Having said that,  you cannot stack two of these Herbie receiver
            > > circuit in series like a couple of photodiodes in a photo bridge.
            > > But you can connect the two analog signals to a couple of
            > comparators
            > > or opamps and use the difference between the opamp output levels
            to
            > > drive a head left or right.
            > >
            > > If you want to dirctly detect the reflected IR light then use a
            > > TSL250 and high pass filter (AC couple) the output to reject
            > ambient
            > > IR light.  The TSL250 application note has more details.
            > >
            > > wilf
            > >
            > >
            > > --- In beam@yahoogroups.com, "firnagzen" <slung@s...> wrote:
            > > >
            > > > The two upper recievers are basically replacements for regular
            > left
            > > > and right light sensors, so that they recieve the reflected IR
            > > light
            > > > instead of regular light.
            > > >
            > > > The reciever at the bottom essentially detects the distance
            > (those
            > > > recievers ARE analog output, right?) and the trimpot reduces
            the
            > > > level a bit. One of those two transistors in the distance
            > > adjustment
            > > > will turn on when the distance is at a certain level. (So that
            > the
            > > > flasher and clicker part fo the circuit don't activate when the
            > bot
            > > > is staring at the wall)
            > > >
            > > >
            > > >
            > > > --- In beam@yahoogroups.com, Joseph Charles <jodicalhon@y...>
            > wrote:
            > > > >
            > > > >
            > > > >   The V+ pin of the middle receiver is connected to the B
            input
            > > of
            > > > the  139. Its only connection to Vcc is via diodes D3 and D4
            and
            > a
            > > > 100k  resistor, which I think will not allow it to operate.
            > > > >  
            > > > >   The 139 enable pin relies on a nice, clean low output from
            > the
            > > > middle receiver.
            > > > >  
            > > > >   If the upper receiver triggers, its output will pulse low,
            > > > reverse  biasing D3 and D4 and the V+ pin of the middle
            receiver
            > > will
            > > > float, as  will input B and, via the 100k and 220k resistors,
            the
            > > > enable pin.
            > > > >  
            > > > >   I'm not sure what each receiver is supposed to do, and I'm
            > not
            > > > sure  about the purpose of the distance adjustment. Perhaps you
            > > could
            > > > give us  your take on the circuit. Sorry I haven't had time to
            > > follow
            > > > your idea  more closely, but I think you need to look at the
            > > > connections I've  mentioned.
            > > > >  
            > > > >   All for now. Its very late here, so please forgive any
            > > > misreadings.
            > > > >  
            > > > >   Jo C
            > > > >  
            > > > >
            > > > > firnagzen <slung@s...> wrote:          Formerly "Using GP2D12
            > in
            > > a
            > > > headbot?"
            > > > >  
            > > > >   Well, I've been discussing with mycroft2152 through e-mail,
            > and
            > > > this is
            > > > >   how the project currently stands.
            > > > >   http://www.maj.com/gallery/nuts-about-
            > > > >   bionicle/BEAM/visitor_irritator.jpg
            > > > >  
            > > > >   Can someone check if the circuitry is correct, and help me
            to
            > > > fill in
            > > > >   the blanks? (There's a couple of parts not figured out
            yet.)
            > > > Credit
            > > > >   goes to Wilf Righter and Frans Storms for the base circuits.
            > > > >  
            > > > >  
            > > > >  
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          • Scott Burns
            Am I correct in assuming that the distance measurement circuit to which you refer is similar to the one in the file 40kHzHerbie3.gif? Scott
            Message 5 of 10 , Nov 29, 2005
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              Am I correct in assuming that the "distance measurement circuit" to which you refer is similar to the one in the file 40kHzHerbie3.gif?

              Scott

              At 10:30 PM 11/28/2005, you wrote:
              I have tested this distance measurement circuit using the ramping IR transmitter pulses with a single PNA4602 and it works very well in moderately light to dark ambient conditions. The average IR LED current is about 50ma and the 38kHz carrier pulse width has not been optimized. The sawtooth modulation frequency is about 100Hz. By filtering the receiver output with a simple RC filter (10Hz), I get an analog output that changes from 5V and 0V when the distance to the reflecting object changes from 1.5m to 0.2m.
               
              Since the range scales with LED brightness, adding 2 LEDs in series or or increasing peak LED currents to 100mA, it should be possible to increase the detection range to greater than 2m.
               
              Rather then using the difference in receiver output pulse width, I suggest using the filtered analog outputs.
               
              Connecting the filtered output of two IR receivers to the (+) and (-) inputs of a comparator would generate a high or low comparator output depending on which receiver detected the stronger (nearer) reflected IR signal. When the two signals are balanced the comparator output would oscillate.  A second comparator can be used with a set point and diode OR'd inputs to determine if either of the reflections are strong enough to indicate the object is within some minimum distance of the sensors.  The outputs of the comparators can be connected to a h-bridge motor driver to enable the motor driver and track objects when they are within a certain distance of the sensors. 
               
              Note that in this context the term "lock'd on" means that equal reflections indicate that the object is centered between the detectors and the head motor is pointing toward the object while rapidly shaking  back and forth ( so rapid as to be invisible or can simply stop using a Power Smart circuit). When the object changes position, the head circuit turns the motor in one or the other direction to "track" the object.
               
              wilf
               
               
               
              ----- Original Message -----
              From: firnagzen
              To: beam@yahoogroups.com
              Sent: Monday, November 28, 2005 7:28 PM
              Subject: [beam] Re: Visitor irritator

              I've been pondering this problem for some time now. I think I may
              have come up with a solution: I use the LB1630 head circuit. Wilf,
              one of the IR sensors will trigger before the other, right? Thus,
              whichever IR sensor triggers first, which is therefore close to the
              nearest object, will cause the head to turn towards that object until
              the other one triggers, thereby shutting down the circuit, right?

              Also, for the lock on, I tie an inverter with a smallish cap to the
              two output lines of the LB1630, and when both go low, the inverters'
              output goes high, and I can use this to run the lock on circuit.

              This would work, right? But I still need help: How can I sense the
              distance from the object to the robot? (I only want the circuit to
              lock on when the object is below a certain distance from the robot.)

              --- In beam@yahoogroups.com, "firnagzen" <slung@s...> wrote:
              >
              > Hmmmmm. So how CAN the 40kHz herbie recievers be applied to the
              > circuit? Or do I have to change it completely? If so, how?Also, it
              > seems that I would have to change the distance detector: Please
              > enlighten me as to how.
              >
              > --- In beam@yahoogroups.com, "wilf_nv" <wrigter@d...> wrote:
              > >
              > >
              > >
              > > The IR receivers are basically digital not analog output. However
              > the
              > > 40KHzHERBIE3 circuit uses a special technique to determine which
              of
              > > the two receivers is detecting higher reflected IR light. This is
              > > done by ramping the 40kHz (or38KHz) IR transmitter current from 0-
              > > 100% brightness. Since each receiver requires a minimum level of
              IR
              > > before it turns on, the output goes active at some point on the
              > > ramping brightness. Since both receivers are exposed to the
              > reflected
              > > light, the receiver which detects the higher reflected IR, will
              > turn
              > > on before the other receiver.  If the ramping waveform is
              repeated
              > at
              > > say 100Hz, then each receiver will have a pulsed output whose
              width
              > > is proportional to the received reflected IR. The difference in
              > width
              > > can be used directly in some case or by integrating these pulses,
              > > each receiver circuit can generate an analog signal between 0-5V
              > that
              > > is proportional to the received IR level.
              > >
              > > Having said that,  you cannot stack two of these Herbie receiver
              > > circuit in series like a couple of photodiodes in a photo bridge.
              > > But you can connect the two analog signals to a couple of
              > comparators
              > > or opamps and use the difference between the opamp output levels
              to
              > > drive a head left or right.
              > >
              > > If you want to dirctly detect the reflected IR light then use a
              > > TSL250 and high pass filter (AC couple) the output to reject
              > ambient
              > > IR light.  The TSL250 application note has more details.
              > >
              > > wilf
              > >
              > >
              > > --- In beam@yahoogroups.com, "firnagzen" <slung@s...> wrote:
              > > >
              > > > The two upper recievers are basically replacements for regular
              > left
              > > > and right light sensors, so that they recieve the reflected IR
              > > light
              > > > instead of regular light.
              > > >
              > > > The reciever at the bottom essentially detects the distance
              > (those
              > > > recievers ARE analog output, right?) and the trimpot reduces
              the
              > > > level a bit. One of those two transistors in the distance
              > > adjustment
              > > > will turn on when the distance is at a certain level. (So that
              > the
              > > > flasher and clicker part fo the circuit don't activate when the
              > bot
              > > > is staring at the wall)
              > > >
              > > >
              > > >
              > > > --- In beam@yahoogroups.com, Joseph Charles <jodicalhon@y...>
              > wrote:
              > > > >
              > > > >
              > > > >   The V+ pin of the middle receiver is connected to the B
              input
              > > of
              > > > the  139. Its only connection to Vcc is via diodes D3 and D4
              and
              > a
              > > > 100k  resistor, which I think will not allow it to operate.
              > > > >  
              > > > >   The 139 enable pin relies on a nice, clean low output from
              > the
              > > > middle receiver.
              > > > >  
              > > > >   If the upper receiver triggers, its output will pulse low,
              > > > reverse  biasing D3 and D4 and the V+ pin of the middle
              receiver
              > > will
              > > > float, as  will input B and, via the 100k and 220k resistors,
              the
              > > > enable pin.
              > > > >  
              > > > >   I'm not sure what each receiver is supposed to do, and I'm
              > not
              > > > sure  about the purpose of the distance adjustment. Perhaps you
              > > could
              > > > give us  your take on the circuit. Sorry I haven't had time to
              > > follow
              > > > your idea  more closely, but I think you need to look at the
              > > > connections I've  mentioned.
              > > > >  
              > > > >   All for now. Its very late here, so please forgive any
              > > > misreadings.
              > > > >  
              > > > >   Jo C
              > > > >  
              > > > >
              > > > > firnagzen <slung@s...> wrote:          Formerly "Using GP2D12
              > in
              > > a
              > > > headbot?"
              > > > >  
              > > > >   Well, I've been discussing with mycroft2152 through e-mail,
              > and
              > > > this is
              > > > >   how the project currently stands.
              > > > >   http://www.maj.com/gallery/nuts-about-
              > > > >   bionicle/BEAM/visitor_irritator.jpg
              > > > >  
              > > > >   Can someone check if the circuitry is correct, and help me
              to
              > > > fill in
              > > > >   the blanks? (There's a couple of parts not figured out
              yet.)
              > > > Credit
              > > > >   goes to Wilf Righter and Frans Storms for the base circuits.
              > > > >  
              > > > >  
              > > > >  
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            • wrigter
              Hi Scott, Yes, that is the circuit adjusted for 38KHz. I will check the actual component values when I get home tonight. The analog values change somewhat with
              Message 6 of 10 , Nov 29, 2005
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                Hi Scott,

                Yes, that is the circuit adjusted for 38KHz. I will check
                the actual component values when I get home tonight. The
                analog values change somewhat with effects of changing
                ambient light and reflectivity but the basic circuit
                provides a good coarse measurement of distance. When two
                identical IR receivers are used in a differential
                measurement, as in this "head" application, these effects
                tend to cancel out and the relative accuracy of the
                measurements should be even better.

                wilf


                > Am I correct in assuming that the "distance measurement
                > circuit" to which you refer is similar to the one in the
                > file 40kHzHerbie3.gif?
                >
                > Scott
                >
                > At 10:30 PM 11/28/2005, you wrote:
                > >I have tested this distance measurement circuit using the
                > ramping IR >transmitter pulses with a single PNA4602 and
                > it works very well in >moderately light to dark ambient
                > conditions. The average IR LED current is >about 50ma and
                > the 38kHz carrier pulse width has not been optimized. The
                > >sawtooth modulation frequency is about 100Hz. By
                > filtering the receiver >output with a simple RC filter
                > (10Hz), I get an analog output that changes >from 5V and
                > 0V when the distance to the reflecting object changes from
                > >1.5m to 0.2m.
                > >
                > >Since the range scales with LED brightness, adding 2 LEDs
                > in series or or >increasing peak LED currents to 100mA,
                > it should be possible to increase >the detection range to
                > greater than 2m. >
                > >Rather then using the difference in receiver output pulse
                > width, I suggest >using the filtered analog outputs.
                > >
                > >Connecting the filtered output of two IR receivers to the
                > (+) and (-) >inputs of a comparator would generate a high
                > or low comparator output >depending on which receiver
                > detected the stronger (nearer) reflected IR >signal. When
                > the two signals are balanced the comparator output would
                > >oscillate. A second comparator can be used with a set
                > point and diode >OR'd inputs to determine if either of
                > the reflections are strong enough to >indicate the object
                > is within some minimum distance of the sensors. The
                > >outputs of the comparators can be connected to a h-bridge
                > motor driver to >enable the motor driver and track
                > objects when they are within a certain >distance of the
                > sensors. >
                > >Note that in this context the term "lock'd on" means that
                > equal >reflections indicate that the object is centered
                > between the detectors and >the head motor is pointing
                > toward the object while rapidly shaking back >and forth
                > ( so rapid as to be invisible or can simply stop using a
                > Power >Smart circuit). When the object changes position,
                > the head circuit turns >the motor in one or the other
                > direction to "track" the object. >
                > >wilf
                > >
                > >
                > >
                > >----- Original Message -----
                > >From: <mailto:slung@...>firnagzen
                > >To: <mailto:beam@yahoogroups.com>beam@yahoogroups.com
                > >Sent: Monday, November 28, 2005 7:28 PM
                > >Subject: [beam] Re: Visitor irritator
                > >
                > >I've been pondering this problem for some time now. I
                > think I may >have come up with a solution: I use the
                > LB1630 head circuit. Wilf, >one of the IR sensors will
                > trigger before the other, right? Thus, >whichever IR
                > sensor triggers first, which is therefore close to the
                > >nearest object, will cause the head to turn towards that
                > object until >the other one triggers, thereby shutting
                > down the circuit, right? >
                > >Also, for the lock on, I tie an inverter with a smallish
                > cap to the >two output lines of the LB1630, and when both
                > go low, the inverters' >output goes high, and I can use
                > this to run the lock on circuit. >
                > >This would work, right? But I still need help: How can I
                > sense the >distance from the object to the robot? (I only
                > want the circuit to >lock on when the object is below a
                > certain distance from the robot.) >
                > >--- In beam@yahoogroups.com, "firnagzen" <slung@s...>
                > > wrote: >
                > > > Hmmmmm. So how CAN the 40kHz herbie recievers be
                > > > applied to the circuit? Or do I have to change it
                > > > completely? If so, how?Also, it seems that I would
                > > > have to change the distance detector: Please enlighten
                > > me as to how. >
                > > > --- In beam@yahoogroups.com, "wilf_nv" <wrigter@d...>
                > > > wrote: >
                > > > >
                > > > >
                > > > > The IR receivers are basically digital not analog
                > > > output. However the
                > > > > 40KHzHERBIE3 circuit uses a special technique to
                > determine which >of
                > > > > the two receivers is detecting higher reflected IR
                > > > > light. This is done by ramping the 40kHz (or38KHz)
                > > > > IR transmitter current from 0- 100% brightness.
                > Since each receiver requires a minimum level of >IR
                > > > > before it turns on, the output goes active at some
                > > > > point on the ramping brightness. Since both
                > > > receivers are exposed to the reflected
                > > > > light, the receiver which detects the higher
                > > > reflected IR, will turn
                > > > > on before the other receiver. If the ramping
                > waveform is >repeated
                > > > at
                > > > > say 100Hz, then each receiver will have a pulsed
                > output whose >width
                > > > > is proportional to the received reflected IR. The
                > > > difference in width
                > > > > can be used directly in some case or by integrating
                > > > > these pulses, each receiver circuit can generate an
                > > > analog signal between 0-5V that
                > > > > is proportional to the received IR level.
                > > > >
                > > > > Having said that, you cannot stack two of these
                > > > > Herbie receiver circuit in series like a couple of
                > > > > photodiodes in a photo bridge. But you can connect
                > > > the two analog signals to a couple of comparators
                > > > > or opamps and use the difference between the opamp
                > output levels >to
                > > > > drive a head left or right.
                > > > >
                > > > > If you want to dirctly detect the reflected IR light
                > > > > then use a TSL250 and high pass filter (AC couple)
                > > > the output to reject ambient
                > > > > IR light. The TSL250 application note has more
                > > > details. >
                > > > > wilf
                > > > >
                > > > >
                > > > > --- In beam@yahoogroups.com, "firnagzen"
                > > > > <slung@s...> wrote: >
                > > > > > The two upper recievers are basically replacements
                > > > for regular left
                > > > > > and right light sensors, so that they recieve the
                > > > > reflected IR light
                > > > > > instead of regular light.
                > > > > >
                > > > > > The reciever at the bottom essentially detects the
                > > > distance (those
                > > > > > recievers ARE analog output, right?) and the
                > trimpot reduces >the
                > > > > > level a bit. One of those two transistors in the
                > > > > distance adjustment
                > > > > > will turn on when the distance is at a certain
                > > > level. (So that the
                > > > > > flasher and clicker part fo the circuit don't
                > > > activate when the bot
                > > > > > is staring at the wall)
                > > > > >
                > > > > >
                > > > > >
                > > > > > --- In beam@yahoogroups.com, Joseph Charles
                > > > <jodicalhon@y...> wrote:
                > > > > > >
                > > > > > >
                > > > > > > The V+ pin of the middle receiver is connected
                > to the B >input
                > > > > of
                > > > > > the 139. Its only connection to Vcc is via diodes
                > D3 and D4 >and
                > > > a
                > > > > > 100k resistor, which I think will not allow it to
                > > > > > operate. >
                > > > > > > The 139 enable pin relies on a nice, clean low
                > > > output from the
                > > > > > middle receiver.
                > > > > > >
                > > > > > > If the upper receiver triggers, its output
                > > > > > will pulse low, reverse biasing D3 and D4 and the
                > V+ pin of the middle >receiver
                > > > > will
                > > > > > float, as will input B and, via the 100k and 220k
                > resistors, >the
                > > > > > enable pin.
                > > > > > >
                > > > > > > I'm not sure what each receiver is supposed to
                > > > do, and I'm not
                > > > > > sure about the purpose of the distance
                > > > > adjustment. Perhaps you could
                > > > > > give us your take on the circuit. Sorry I haven't
                > > > > had time to follow
                > > > > > your idea more closely, but I think you need to
                > > > > > look at the connections I've mentioned.
                > > > > > >
                > > > > > > All for now. Its very late here, so please
                > > > > > forgive any misreadings.
                > > > > > >
                > > > > > > Jo C
                > > > > > >
                > > > > > >
                > > > > > > firnagzen <slung@s...> wrote: Formerly
                > > > "Using GP2D12 in
                > > > > a
                > > > > > headbot?"
                > > > > > >
                > > > > > > Well, I've been discussing with mycroft2152
                > > > through e-mail, and
                > > > > > this is
                > > > > > > how the project currently stands.
                > > > > > >
                > >
                > <http://www.maj.com/gallery/nuts-about->http://www.maj.com
                > > > > > > /gallery/nuts-about-
                > > > > > bionicle/BEAM/visitor_irritator.jpg >
                > > > > > > Can someone check if the circuitry is correct,
                > and help me >to
                > > > > > fill in
                > > > > > > the blanks? (There's a couple of parts not
                > figured out >yet.)
                > > > > > Credit
                > > > > > > goes to Wilf Righter and Frans Storms for the
                > > > > > base circuits. >
                > > > > > >
                > > > > > >
                > > > > > >
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              • wrigter
                Hi Scott, Yes, that is the circuit adjusted for 38KHz. I will check the actual component values when I get home tonight. The analog values change somewhat with
                Message 7 of 10 , Nov 29, 2005
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                  Hi Scott,

                  Yes, that is the circuit adjusted for 38KHz. I will check
                  the actual component values when I get home tonight. The
                  analog values change somewhat with effects of changing
                  ambient light and reflectivity but the basic circuit
                  provides a good coarse measurement of distance. When two
                  identical IR receivers are used in a differential
                  measurement, as in this "head" application, these effects
                  tend to cancel out and the relative accuracy of the
                  measurements should be even better.

                  wilf


                  > Am I correct in assuming that the "distance measurement
                  > circuit" to which you refer is similar to the one in the
                  > file 40kHzHerbie3.gif?
                  >
                  > Scott
                  >
                  > At 10:30 PM 11/28/2005, you wrote:
                  > >I have tested this distance measurement circuit using the
                  > ramping IR >transmitter pulses with a single PNA4602 and
                  > it works very well in >moderately light to dark ambient
                  > conditions. The average IR LED current is >about 50ma and
                  > the 38kHz carrier pulse width has not been optimized. The
                  > >sawtooth modulation frequency is about 100Hz. By
                  > filtering the receiver >output with a simple RC filter
                  > (10Hz), I get an analog output that changes >from 5V and
                  > 0V when the distance to the reflecting object changes from
                  > >1.5m to 0.2m.
                  > >
                  > >Since the range scales with LED brightness, adding 2 LEDs
                  > in series or or >increasing peak LED currents to 100mA,
                  > it should be possible to increase >the detection range to
                  > greater than 2m. >
                  > >Rather then using the difference in receiver output pulse
                  > width, I suggest >using the filtered analog outputs.
                  > >
                  > >Connecting the filtered output of two IR receivers to the
                  > (+) and (-) >inputs of a comparator would generate a high
                  > or low comparator output >depending on which receiver
                  > detected the stronger (nearer) reflected IR >signal. When
                  > the two signals are balanced the comparator output would
                  > >oscillate. A second comparator can be used with a set
                  > point and diode >OR'd inputs to determine if either of
                  > the reflections are strong enough to >indicate the object
                  > is within some minimum distance of the sensors. The
                  > >outputs of the comparators can be connected to a h-bridge
                  > motor driver to >enable the motor driver and track
                  > objects when they are within a certain >distance of the
                  > sensors. >
                  > >Note that in this context the term "lock'd on" means that
                  > equal >reflections indicate that the object is centered
                  > between the detectors and >the head motor is pointing
                  > toward the object while rapidly shaking back >and forth
                  > ( so rapid as to be invisible or can simply stop using a
                  > Power >Smart circuit). When the object changes position,
                  > the head circuit turns >the motor in one or the other
                  > direction to "track" the object. >
                  > >wilf
                  > >
                  > >
                  > >
                  > >----- Original Message -----
                  > >From: <mailto:slung@...>firnagzen
                  > >To: <mailto:beam@yahoogroups.com>beam@yahoogroups.com
                  > >Sent: Monday, November 28, 2005 7:28 PM
                  > >Subject: [beam] Re: Visitor irritator
                  > >
                  > >I've been pondering this problem for some time now. I
                  > think I may >have come up with a solution: I use the
                  > LB1630 head circuit. Wilf, >one of the IR sensors will
                  > trigger before the other, right? Thus, >whichever IR
                  > sensor triggers first, which is therefore close to the
                  > >nearest object, will cause the head to turn towards that
                  > object until >the other one triggers, thereby shutting
                  > down the circuit, right? >
                  > >Also, for the lock on, I tie an inverter with a smallish
                  > cap to the >two output lines of the LB1630, and when both
                  > go low, the inverters' >output goes high, and I can use
                  > this to run the lock on circuit. >
                  > >This would work, right? But I still need help: How can I
                  > sense the >distance from the object to the robot? (I only
                  > want the circuit to >lock on when the object is below a
                  > certain distance from the robot.) >
                  > >--- In beam@yahoogroups.com, "firnagzen" <slung@s...>
                  > > wrote: >
                  > > > Hmmmmm. So how CAN the 40kHz herbie recievers be
                  > > > applied to the circuit? Or do I have to change it
                  > > > completely? If so, how?Also, it seems that I would
                  > > > have to change the distance detector: Please enlighten
                  > > me as to how. >
                  > > > --- In beam@yahoogroups.com, "wilf_nv" <wrigter@d...>
                  > > > wrote: >
                  > > > >
                  > > > >
                  > > > > The IR receivers are basically digital not analog
                  > > > output. However the
                  > > > > 40KHzHERBIE3 circuit uses a special technique to
                  > determine which >of
                  > > > > the two receivers is detecting higher reflected IR
                  > > > > light. This is done by ramping the 40kHz (or38KHz)
                  > > > > IR transmitter current from 0- 100% brightness.
                  > Since each receiver requires a minimum level of >IR
                  > > > > before it turns on, the output goes active at some
                  > > > > point on the ramping brightness. Since both
                  > > > receivers are exposed to the reflected
                  > > > > light, the receiver which detects the higher
                  > > > reflected IR, will turn
                  > > > > on before the other receiver. If the ramping
                  > waveform is >repeated
                  > > > at
                  > > > > say 100Hz, then each receiver will have a pulsed
                  > output whose >width
                  > > > > is proportional to the received reflected IR. The
                  > > > difference in width
                  > > > > can be used directly in some case or by integrating
                  > > > > these pulses, each receiver circuit can generate an
                  > > > analog signal between 0-5V that
                  > > > > is proportional to the received IR level.
                  > > > >
                  > > > > Having said that, you cannot stack two of these
                  > > > > Herbie receiver circuit in series like a couple of
                  > > > > photodiodes in a photo bridge. But you can connect
                  > > > the two analog signals to a couple of comparators
                  > > > > or opamps and use the difference between the opamp
                  > output levels >to
                  > > > > drive a head left or right.
                  > > > >
                  > > > > If you want to dirctly detect the reflected IR light
                  > > > > then use a TSL250 and high pass filter (AC couple)
                  > > > the output to reject ambient
                  > > > > IR light. The TSL250 application note has more
                  > > > details. >
                  > > > > wilf
                  > > > >
                  > > > >
                  > > > > --- In beam@yahoogroups.com, "firnagzen"
                  > > > > <slung@s...> wrote: >
                  > > > > > The two upper recievers are basically replacements
                  > > > for regular left
                  > > > > > and right light sensors, so that they recieve the
                  > > > > reflected IR light
                  > > > > > instead of regular light.
                  > > > > >
                  > > > > > The reciever at the bottom essentially detects the
                  > > > distance (those
                  > > > > > recievers ARE analog output, right?) and the
                  > trimpot reduces >the
                  > > > > > level a bit. One of those two transistors in the
                  > > > > distance adjustment
                  > > > > > will turn on when the distance is at a certain
                  > > > level. (So that the
                  > > > > > flasher and clicker part fo the circuit don't
                  > > > activate when the bot
                  > > > > > is staring at the wall)
                  > > > > >
                  > > > > >
                  > > > > >
                  > > > > > --- In beam@yahoogroups.com, Joseph Charles
                  > > > <jodicalhon@y...> wrote:
                  > > > > > >
                  > > > > > >
                  > > > > > > The V+ pin of the middle receiver is connected
                  > to the B >input
                  > > > > of
                  > > > > > the 139. Its only connection to Vcc is via diodes
                  > D3 and D4 >and
                  > > > a
                  > > > > > 100k resistor, which I think will not allow it to
                  > > > > > operate. >
                  > > > > > > The 139 enable pin relies on a nice, clean low
                  > > > output from the
                  > > > > > middle receiver.
                  > > > > > >
                  > > > > > > If the upper receiver triggers, its output
                  > > > > > will pulse low, reverse biasing D3 and D4 and the
                  > V+ pin of the middle >receiver
                  > > > > will
                  > > > > > float, as will input B and, via the 100k and 220k
                  > resistors, >the
                  > > > > > enable pin.
                  > > > > > >
                  > > > > > > I'm not sure what each receiver is supposed to
                  > > > do, and I'm not
                  > > > > > sure about the purpose of the distance
                  > > > > adjustment. Perhaps you could
                  > > > > > give us your take on the circuit. Sorry I haven't
                  > > > > had time to follow
                  > > > > > your idea more closely, but I think you need to
                  > > > > > look at the connections I've mentioned.
                  > > > > > >
                  > > > > > > All for now. Its very late here, so please
                  > > > > > forgive any misreadings.
                  > > > > > >
                  > > > > > > Jo C
                  > > > > > >
                  > > > > > >
                  > > > > > > firnagzen <slung@s...> wrote: Formerly
                  > > > "Using GP2D12 in
                  > > > > a
                  > > > > > headbot?"
                  > > > > > >
                  > > > > > > Well, I've been discussing with mycroft2152
                  > > > through e-mail, and
                  > > > > > this is
                  > > > > > > how the project currently stands.
                  > > > > > >
                  > >
                  > <http://www.maj.com/gallery/nuts-about->http://www.maj.com
                  > > > > > > /gallery/nuts-about-
                  > > > > > bionicle/BEAM/visitor_irritator.jpg >
                  > > > > > > Can someone check if the circuitry is correct,
                  > and help me >to
                  > > > > > fill in
                  > > > > > > the blanks? (There's a couple of parts not
                  > figured out >yet.)
                  > > > > > Credit
                  > > > > > > goes to Wilf Righter and Frans Storms for the
                  > > > > > base circuits. >
                  > > > > > >
                  > > > > > >
                  > > > > > >
                  > > > > > >
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