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 Robotics / Handy Board / 1538
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Subject: 
Re: IR Collision avoidance
Newsgroups: 
lugnet.robotics.handyboard
Date: 
Mon, 24 Feb 1997 23:57:19 GMT
Original-From: 
Chris Moore <cmoore@cancun.rose.hpNOSPAM.com>
Viewed: 
1445 times
  
The Handyboard has a circuit (U7a, R4, C6) that generates a 38KHz signal.
That drives an amplifier that then goes to J7, the IR LED output.  If you
hookup an IR LED to this jack (with a series resistor) then when you turn
on TOC2 using ir_xmit_on() the IR pulse at a rate of 38KHz.

The IR decoders turn on an output when they detect IR light pulsed at a
rate of 38 KHz (or there abouts).

I have my IR LED's hooked up like this:

              220 Ohm
    o--------/\/\/\--------------+-------------+---------------+
J7  o                          (LED)         (LED)           (LED)
    o----------------------------+-------------+---------------+


Each of the detectors is hooked to a digital input like this:

                            +--------+
    o-----------------------| 3      |    Ground
    o-----------------------| 2      |    +5
                            |        |
    o-----------------------| 1      |    Signal
                            +--------+

Other than the 38KHz modulation that the board does in hardware I'm not
pulsing the LEDs.  I just turn them on, at the decoder to see if I see
the light reflected from them, then turn them off.

Hope that clears it up.

Chris


On Feb 24,  3:16pm, Bill Rose wrote:

You put your message on the mailing list concerning the IR avoidance.  I
have a question about the hardware also.  How are the leds powered?  Are you
pulsing them some way or what?  I guess the decoder is what is wired into
the digital ports?  Am I right about this?  I just don't catch how you are
powering the leds.

Thanks,

Bill Rose
brose@ipa.net



Message has 1 Reply:
  Re: IR Collision avoidance
 
(...) What are the three LED's for? (28 years ago, 28-Feb-97, to lugnet.robotics.handyboard)

Message is in Reply To:
  IR Collision avoidance
 
Chris or anyone who cares to respond, You put your message on the mailing list concerning the IR avoidance. I have a question about the hardware also. How are the leds powered? Are you pulsing them some way or what? I guess the decoder is what is (...) (28 years ago, 24-Feb-97, to lugnet.robotics.handyboard)

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