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Infrared Remote controll Help — Parallax Forums

Infrared Remote controll Help

jdpetersdocjdpetersdoc Posts: 26
edited 2008-03-31 15:53 in Robotics
·· I read about the remote with the boe-bot, I have another Board of education, I was thing If the boe-bot can be controlled by another BOE. I need the remote code from the Soney Remote, is there anyway I can find out?? I would be cool to have the boe-bot be controlled by another BOE, I have the buttons so its like the remote.

Comments

  • ercoerco Posts: 20,256
    edited 2008-03-30 14:45
    Interesting problem. The simplest solution is to use a $5 universal TV remote, but the question is whether the BS2 is fast enough to send the signal. What little I know is based on the Parallax IR Ap Kit (#29112, pdf online) and the Robotics with the Boe-Bot book. You will need that info to proceed.

    The BS2 uses harmonics to make the necessary 38.5 kHz carrier frequency to drive an IR LED using its freqout command, like FREQOUT 14,1,38500. But that 1 means send it for 1 millisecond, AFAIK that's the shortest tone burst it can send. The Sony codes are essentially morse code bursts of duration 0.6 and 1.2 milliseconds, so it may be that the Stamp's resolution isn't fine enough.

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    ·"If you build it, they will come."
  • HumanoidoHumanoido Posts: 5,770
    edited 2008-03-30 16:43
    Controlling one BoeBot with another, and not the SONY remote,
    opens up all new possibilities for setting new timing standards,
    particular to the BoeBot. This timing envelop can be longer than
    than a one millisecond packet. The IR receiver code can be
    written to listen for this timing signal. This will open up some
    new issues of concern such as range, direction, and power of
    the transmitted IR signal.

    humanoido
  • ercoerco Posts: 20,256
    edited 2008-03-30 16:46
    Two possible alternatives:
    1) Forget the Sony codes, their use is predicated on the specific desire to use an existing remote control and decode them. You can make up your own code system of pulses and use that. For instance, you'll still use the FREQOUT 14,1,38500 command, or something similar to send a 1 millisecond pulse, then pause 1 ms. Loop that N times to send a certain control signal. Receive the pulses with a Waitrony IR module and simply COUNT them to decode. That is, 5 pulses means go forward, 7 means left, 9 means right, etc.

    2) If you're married to the Sony codes, hack into a universal remote and have your BoE outputs switch several remote keys. But watch out, or BoE will gain control of your cable box and order PPV movies while you're away.

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    ·"If you build it, they will come."
  • HumanoidoHumanoido Posts: 5,770
    edited 2008-03-30 17:34
    Erco has a good idea. It's only a 5 to 7 dollar remote
    and the actual extracted board size is relatively small
    to fit on a Boe-Bot. It can be tapped into the existing
    Boe-Bot batteries, and a Basic Stamp 2 port matrix
    can control the remote board switching. Then, you
    don't need to worry about any timing or code, other
    than some simple switching. The controller hack is also
    a viable solution for other robots as well, such as
    Penguin and Toddler.

    humanoido
  • jdpetersdocjdpetersdoc Posts: 26
    edited 2008-03-31 00:29
    Ok I thing I will make my own code, thanks guys, erco that would be funny if the BOE would hack into my cable box lol.
  • ercoerco Posts: 20,256
    edited 2008-03-31 00:34
    A lot of of interesting possibilities already discussed here. PhiPi had a great post at· http://forums.parallax.com/showthread.php?p=713833 about using an external oscillator to generate the 38 kHz carrier, then just modulating that with Stamp's timing pulses. You could probably generate Sony IR codes even with a BS1,·which can send· PULSOUTs as short as 10 microseconds (Sony codes are 600 uS) to modulate a simple LM555 pulse generator circuit.

    Even more interesting to me is making an IR data link using the SEROUT command to send continuously through an LM555.·I bet·someone here could·quote·the fastest data rate·that could reliably be·sent over that 38 kHz IR carrier, maybe 600 or 1200 baud?

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    ·"If you build it, they will come."
  • jdpetersdocjdpetersdoc Posts: 26
    edited 2008-03-31 00:42
    I have a 555 timmer IC, can I see the schmatce
  • ercoerco Posts: 20,256
    edited 2008-03-31 03:53
    The schematic at http://davebodnar.com/railway/Pulsed_IR_Article/ is simple and works very well. But don't connect the 555's reset pin 4 to +5 volts as shown there, that will be your control signal input, so send your code there from your Basic Stamp's output pin. Making the 555 pin 4 high will turn on the oscillator and emit the 38-40 kHz signal (whatever you adjust the 10K pot for, I like 39 kHz). Power the 555·with your Stamp's +5 volt supply, and you can adjust the IR LEDs series resistor (470 ohms shown) to change the signal intensity. I used 100 ohms.

    I wrote a snippet of code that sends a single Sony control code successfully; code attached for a BS2. Timing is critical, I think you'll have to·program each code signal as a·group of PULSOUTs to keep up.·My code is sent out through pin 15 to drive the 555 circuit. I needed a slight delay (~600 mS) between my PULSOUT 15s, so I inserted·several PULSOUT 14s that don't do anything but slow things down a bit.·The last part of the program was an experiment just to send a steady stream of pulses from the 555 circuit.· Looks like the upper frequency limit is about 2 kHz, and that's in a·very short loop.

    That's plenty for now. I'll post any serial data results·I get here later.

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    ·"If you build it, they will come."
  • jdpetersdocjdpetersdoc Posts: 26
    edited 2008-03-31 15:53
    Thanks thats a big help, ill dig out my old electronics learning lab its full of parts I need.
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