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Using wired "IR-in" port on consumer devices?

bobbob Posts: 296
in AMX Technical Discussion
Anyone have a hint how to connect a wired "IR-in" port found on some consumer gear to AMX equipment? Like for instance on the Oppo HM-31 HDMI switch (it also has RS-232 but there are others too). Thanks!

Comments

  • viningvining Posts: 4,368
    You mean a standard 3.5mm jack? If so just get some 3.5mm to 3.5mm cables from Xantech or where ever and cut them in two. If it doesn't work at first reverse the polarity but the tip should be positive and the ring negative. If you have a tester you can do a simple continuity check.
  • AuserAuser Posts: 506
    Varies according to manufacturer. Some such as the Sony S-Link/Control A1 interfaces (not strictly wired IR, but...) require you to invert the signal (the line floats high and a logic high is registered by pulling it to ground) while others don't. Some want the IR waveform stripped of the carrier while others don't.

    As Vining said, it shouldn't hurt to try plugging in directly and spitting IR at it with the carrier on and then off. If you do a little snooping with a multimeter it should be obvious if the input floats high and you need to invert the signal (I always drive the base of a transistor through a resistor to achieve this).
  • bobbob Posts: 296
    The IR-in port on the devices I am looking at should be Xantech compaible (at least they something like this). So, for the basic test I am going to get a mono 3.5mm cable and connect the tip to + and sleeve to - on the IR/SERIAL ports of the NXI. Is that right?! Thanks again!
  • ericmedleyericmedley Posts: 4,177
    If I ruled the world there would be wired IR ports and descrete Power On/Off and source commands for everyone.
  • bobbob Posts: 296
    Looking at this image http://farm3.static.flickr.com/2671/3977087957_bf9bb7437c_o.jpg (complete thread here http://www.networkedmediatank.com/showthread.php?tid=29013&page=1) it seems that the Popcorn Hour C-200 uses a stereo 3.5mm plug with Ground, +5V and Data. Is it still safe to connect the (stereo) 3.5mm IR-control port directly to the IR-port of a Netlinx, probably shortening Ground and +5V? Thanks for any insights.
  • AuserAuser Posts: 506
    Should be OK. Note that the IR receiver in the picture will send out a demodulated pulse train (ie. turn the carrier off on the NetLinx IR port).
  • bobbob Posts: 296
    Great, thanks much!
  • Jimweir192Jimweir192 Posts: 502
    bob wrote: »
    probably shortening Ground and +5V?

    I wouldn't do that - just use the gnd and data pins to connect to the IR port - leave the +5v disconnected.
  • AuserAuser Posts: 506
    Jimweir192 wrote: »
    I wouldn't do that - just use the gnd and data pins to connect to the IR port - leave the +5v disconnected.

    Good point, I was thinking by shortening you meant shortening the ring and sleeve conductors on the jack. By shortening I hope you don't mean shorting. Connecting GND to +5V would be a very, very bad thing. +5V should be left unconnected.
  • bobbob Posts: 296
    Guys, thanks much!
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