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Ir reader for cable tv remote controls — Parallax Forums

Ir reader for cable tv remote controls

Reyp2000Reyp2000 Posts: 10
edited 2014-09-07 00:31 in Propeller 1
I don't know if it is the right place for this post. I have been trying to find out if anybody have ever tried
reading the IR code of the CATV remote controls. I have no problem reading the Parallax Universal Remote
with the IR receiver with my Prop BOE using spin but I can't seems to be able to read the cable remotes.

Any help or direction is appreciated.

Thanks you.

Rey

Comments

  • Ron CzapalaRon Czapala Posts: 2,418
    edited 2014-08-27 05:52
    http://en.wikipedia.org/wiki/Consumer_IR
    Since the Consumer IR protocols are for the most part not standardized, computers and universal remotes often memorize a bit stream, possibly with compression and possibly without determining the actual bit rate, and play it back. Similarities between remotes are often largely the accidental result of the finite selection of infrared encoder/decoder chips (though now microcontrollers are also used) and IR receiver modules or imitation of the older chips rather than by design. Manufacturers of consumer appliances often reuse the same protocol on many similar devices, though for each manufacturer and device type there are usually multiple protocols in use. The code listings inform about for any universal remote.
  • PublisonPublison Posts: 12,366
    edited 2014-08-27 05:57
    Try this from the OBEX:

    http://obex.parallax.com/object/290

    Do a search in the OBEX for other IR objects.
  • wmosscropwmosscrop Posts: 409
    edited 2014-08-27 06:02
    Rey,

    Do a search in Obex for "IR". One of these objects should work for your remote.

    If I remember correctly, I used Magic IR for my Motorola cable box replacement remote control project.

    Walter
  • cavelambcavelamb Posts: 720
    edited 2014-08-27 06:59
    OP asked about the "cable" codes.
    The OBEX object that I use ( IR_Remote_NewCog.spin by Tom Doyle 2 March 2007) returns TV codes.
    SOME of the cable and DVD codes are returned as numeric codes.
    But that's all I see coming from it.

    To the OP...
    I haven't used it (yet?) but I recall a project that could capture the codes (pulse train) from almost
    any universal remote. Once you had codes in hand, I'm sure you can make it work right.

    Maybe someone here knows more about that?
  • PublisonPublison Posts: 12,366
    edited 2014-08-27 07:15
    I believe that's the one I posted in Post #3
    IR Kit contain objects to get and buffer key codes from virtually any IR remote, identify and obtain timing information, transmit IR codes, and understand IR transmission codes. (IR_kit.zip)
  • cavelambcavelamb Posts: 720
    edited 2014-08-27 19:15
    That's double good news today, Pub.

    Not only is that the object of our desire, the OBEX is up again.

    I don't really think the obex was down, mind you.
    But during the conference it wasn't happening from here.

    Thanks.
  • Reyp2000Reyp2000 Posts: 10
    edited 2014-08-29 00:55
    Thanks everybody. I downloaded the IR.kit.zip and Beau's IR.Functions_DEMO and both did not work
    with the Cable tV remote that I have. But it does work with the Parallax Universal Remote in Sony mode.

    So I decided to burrow a cable TV box and remove the IR receiver. That work with both the Parallax
    Universal Remote and the Cable TV remote. See attach pix - the first waveform is the #1 button of the
    parallax universal remote and the second is the #1 button from the cable TV remote. The IR recover pix
    is the burrowed IR receiver.

    The IR receiver don't have any markings or labels so I don't know who made it so I can buy it from digikey or mouser.
    Anybody have any idea or recommendation of what type of IR receiver this is and where I can buy one of this.
    Beside trying to get more cable tv box and burrow the IR receivers?

    Thanks.

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  • KMyersKMyers Posts: 433
    edited 2014-08-30 09:17
    Hi, used to have all the codes for the GI & SA boxes but that was on my computer at work which I left 10 years ago. However the manufactures have info on their web sites and most of the cable box remotes are generic. Their web sites also should have this info. Most of my CATV contacts have moved on in life....
  • RaymanRayman Posts: 14,657
    edited 2014-09-02 08:14
    I'm not an expert on this, but I think some receivers work on different frequencies.
    I think that 38 kHz is the modulation from regular TV remote controls.
    Maybe your cable company is using some different frequency for some reason...

    If you had an IR photodiode, maybe you could rig up a circuit and figure out the modulation frequency.
    Or, buy different frequency receivers and hope to get lucky...

    The TSOP38238 is one I just bought for 38 kHz. But, if you look at that datasheet, you'll see versions with 5 other carrier frequencies...
  • PublisonPublison Posts: 12,366
    edited 2014-09-02 08:26
    Dominant frequencies seem to be 38 and 36 Khz.
  • KMyersKMyers Posts: 433
    edited 2014-09-02 08:42
    Yes those are the most common BUT different manufactors use different bit schemes that universal remotes cant get. I have a Sylvania LCD that I am stuck with their remote. Also my Bose sound system not all universal remotes work with.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2014-09-02 08:46
    Linux has a IR project that includes a huge database of commercial remotes and their related formats.

    From what I have gathered, there are really only 4 main systems of variation, though codes can be anywhere from 8bits to 32 bits wide, possibly wider.

    The systems have to do with their starting sequence, and a modulation protocol.

    www.Lirc.org

    Capturing the signals on a scope is a start, but it helps to be able to confirm which protocol it is against a database.

    It seems like your IR reciever is working well and that what you are getting might be a 24bit code. The Parallax examples often default to a Sony code that is 8bits for the buttons followed by 4 bits for the device.

    If you have Windows only, a LiveCD of Linux ... such as Puppy Linux can run the LIRC software from a CD or DVD without affecting your hard disk.
  • PublisonPublison Posts: 12,366
    edited 2014-09-02 08:52
    KMyers wrote: »
    Yes those are the most common BUT different manufactors use different bit schemes that universal remotes cant get. I have a Sylvania LCD that I am stuck with their remote. Also my Bose sound system not all universal remotes work with.

    Once you find the frequency, the code in post #3 should be able to "sniff" it out.
  • Reyp2000Reyp2000 Posts: 10
    edited 2014-09-05 02:55
    I found one Vishay TSOP1238 IR receiver and this one work with the Motorola and the SA/CISCO remote control that I have. Looking at the spec it is similar to Rayman's TSOP38238 (posting #10). I also downloaded the IR_KIT.ZIP and that was able to sniff out the codes from my 2 remote controls. Thanks for all your great comments and suggestions.
  • RaymanRayman Posts: 14,657
    edited 2014-09-05 19:48
    Glad you figured your problem out. I have also figured out my problem and that was that my header was 180 degrees out... Anyway, put my TSOP38238 on the other side of the board and now Beau's IR_KIT sees my TV remote.
    Also, one thing about Beau's code is that it sees the code and says "no match".
    But, that no match is against some stored pattern which couldn't possibly match my TV remote anyway...
  • KMyersKMyers Posts: 433
    edited 2014-09-06 08:24
    Publison wrote: »
    Once you find the frequency, the code in post #3 should be able to "sniff" it out.

    Grin, too many years working with that and to lazy. :tongue :Maybe this winter...
  • Beau SchwabeBeau Schwabe Posts: 6,566
    edited 2014-09-06 11:13
    "...one thing about Beau's code is that it sees the code and says "no match".
    But, that no match is against some stored pattern which couldn't possibly match my TV remote anyway..."     - That is correct. The decoder works independent of the matching, while the matching is done with information provided with previous decodes in an iterative process.
  • RaymanRayman Posts: 14,657
    edited 2014-09-07 00:31
    Thanks so much for that code Beau!
    I have a goal of turning my psm3 device into a learning super remote and you code make it look easy to do
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