Remote control anything

Discussion in 'The Projects Forum' started by walkonfire, Apr 15, 2006.

  1. walkonfire

    Thread Starter Member

    Apr 5, 2006
    13
    0
    I was wondering how to build a receiver circuit that detects the output from any of my pile of remote controls.

    I can give you specifics on the remotes, if needed, but it would seem that any of them could be used to trigger an on/off switch remotely.

    I'm assuming the transmitter is an LED diode flashing some pre-programmed sequence. I can see the flashes using my camcorder. Seems like if I bought a cheap RadioShack LED receiver, I could then build a circuit arond it that would toggle ON/OFF.

    I'm not an EE, but I did take EE (DC and AC) in college.... which means I know just enough to be dangerous. I promise, I'll just use AAA batteries and a well-grounded screwdriver.

    Assume, for discussion, that I want to turn a flashlight bulb on and off using the TV remote.

    Thanks.
     
  2. kubeek

    AAC Fanatic!

    Sep 20, 2005
    4,670
    804
    To switch something on/off by TV remote isn´t that easy, because each tv-brand has its own sequence that is sent by the remote control. You can make it for one of your remotes, or only for those you programme into some processor.

    I don´t know what kind of coding they use, but it can also depend on the manufacturer. Some really old types maybe can be read discretely, but probably only for one or two of the buttons.
     
  3. paultwang

    Well-Known Member

    Mar 8, 2006
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    What about just an infrared detector? Maybe too many false positives.
     
  4. pebe

    AAC Fanatic!

    Oct 11, 2004
    628
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    Use a simple IR detector and feed its output pulses through a diode to a parallel CR network (a simple envelope detector), so you get one long pulse as long as you hold a key down. Don't use a 38KHz receiver because not all TV remotes use that system.

    You can then use the pulse to trigger a bistable back and forth to give on/off switching.
     
  5. windoze killa

    AAC Fanatic!

    Feb 23, 2006
    605
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    It is quite an easy task really. Every button on the remote gives out a different binary code or sometimes PCM signal. You need to build something that will decode the signal and operate what ever is connected to the outputs. Now for the easy bit. For the receiver try and scavenge the circuit area out of the TV or video that has the receiver. If you don't have the TV you should be able to get a schematic for it on the web somewhere and build it from there.

    As Kubeek said, each TV or video uses different codes so you need to match up the receiver to the remote.

    Another option is to build a receiver with a micro that that can detect the codes and store them. This would be a little more complex but a lot more flexible in the long run.
     
  6. pebe

    AAC Fanatic!

    Oct 11, 2004
    628
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    Walkonfire said he wants to use *any* of his remote controls, so it's got to be a universal decoder.
     
  7. windoze killa

    AAC Fanatic!

    Feb 23, 2006
    605
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    Walkonfire, do you want to be able to control various items with the remote? Or do you just want to be able to turn on one item with the push of any button?
     
  8. noltex

    Member

    Apr 18, 2006
    15
    0
    I got a few of these IR remote control receiver kits here. They work very well in the dark, although not nearly as well in day or room level light, using ANY IR remote control, TV, VCR, DVD, whatever. I haven't found one yet it doesn't work with. Distance can be as much as 20-30 feet in complete dark. It is a 3V circuit and can be used with a relay for easy switching. I've got it hooked to a small laser for a project I'm working on and it's been very reliable. At $6 each you can't beat them.

    I just found this forum today and am excited to have a resource for projects.
     
  9. walkonfire

    Thread Starter Member

    Apr 5, 2006
    13
    0
    I think Pebe's strategy is on track with where I'm trying to get. Noltex's circuits sound promising, too.

    Quick question for Pebe (or anyone else) .... CR circuit?... Capacitor/Resistor, right?

    ( told you I was marginal on the EE stuff ). I'm assuming experimenting with the capacitance will vary the decay and thus the threshold voltage to to make the pulses look "ON" instead of pulsing.

    Also, what is a "bistable"? some sort of IC?

    Thanks for the help guys!!
     
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