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Universal Remote control , more universal mod?

Discussion in 'Electronic Repair' started by N_Cook, Aug 8, 2010.

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  1. N_Cook

    N_Cook Guest

    Am I on a hiding to nothing? trying to crack a device with unavailable
    remote control, and no button functions to speak of. Is there a technique of
    sniffing a microcontroller to at least find the basic pulse repition rate?
    perhaps inductive loop over the package or monitoring to nA level in supply
    current would register a blip, or is it all or nothing?
    Anyway
    First tried this with Mitsubishi BD 512 "universal" rc
    Removed the 4MHz resonator and fed in a sig gen of about 1.5V pk-pk
    (previously scoped), floating from the rc battery levels. With a known
    receiver and transmitter code selected, then functions would work over range
    3.3 to 5.8M then fail outside that. The rc would work with 1.5V sine between
    300K and 10.5M. Didn't continue with that one as you had to manually step
    through each in-built code.

    Got a few no-name URCs from UK Poundland "pound shop" , badged as Signalex ,
    81415, 10 in 1 . 1 GBP for all the functionality of a URC. This type you can
    set it to flicker away to itself until it reaches the end of a batch of
    codes.
    Removed the 3.58MHz resonator (why so apparently accurate?) . With 1.5V
    pk-pk locked in with receiver over range 2.7 to 5.1M, and again about 300K
    to 11M would operate using 1.5V. So far have only used with original 3.58M ,
    6M and 7.5M sine inputs. Am I serendipitously likely to get a hit
    somewhere, at least the unit on/off model recognition code if not function
    code plus the model code

    So 2 out of 2 of these URC have been amenable to this mod but no match to
    the unit in question found so far. Is there any general guidelines for
    makers to choose certain types/ranges of coding for different types of
    equipment or is it totally open for them to choose? Assorted bits of kit
    show at least partial responses to some of these off-spec codes, but not my
    target one so far.
     
  2. That's the NTSC color carrier frequency. Not only were they made in the
    billions over the years (every US/Canada/Japan, etc) color TV had one,
    so did every VCR, and lots of other things.

    I'm sure they will still be around for a while because while digital TV
    has taken over in the US, it has not in the entire world and anything with
    a composite video input or output needs one.

    They became the defacto standard for things like telephone dialers,
    and many things that needed about a 4mHz crystal because they were so cheap
    and plentyful.

    One of the famous "blue boxes" (telephone hacking devices) was made by
    taking a Radio Shack tone dialer and replacing the 1mHz crystal with a
    3.58mHz one.

    Look up LIRC (Linux Ifrared Remote Control). There is a library of remote
    codes, a way of capturing new ones from a remote and since the definitions
    are in a text file, they are easy to "hack".

    There are all sorts of input and output devices, if you have a PC with a
    regular serial port (not USB), you can build a transmitter from the proper
    plug, a resistor and an IR LED.

    Geoff.
     
  3. N_Cook

    N_Cook Guest

    it. :)

    I was not aware of that frequency as being significant , the equivalent over
    here is millions of 4.433619MHz and x2 of that , quartz crystals for Phase
    Alternate Line. That would explain why it was Never The Same Color (twice)
    if they could get away with using ceramic resonators rather than quartz.

    I'd already looked at LIRC but no listing for my device. Yes easy enough to
    knock up an IR transmitter tacked onto a PC but I've not found a library of
    codes or algorithm for generating all permutations of IR transmitter codes,
    model trigger code or model plus functions
     
  4. Often the ceramic resonators were used as filters and for devices that were
    designed to work at those frequencies, but where it was not critical.

    I no longer have an LIRC setup to do it with, as I replaced my MythTV box with
    a WD TV Live. If you can find someone with a little PERL programing experience,
    they could write a program to copy each remote over to the LIRC config file,
    restart the LIRC daemon and send some codes.

    Then it would wait for you to hit a key, and try the next one.

    It does not have to be very accurate, for example, if your program were to send
    off, vol up, vol down, channel up, channel down, start and stop and something
    happens at all, you have the correct frequency, spacing etc. From there,
    you could play around to get the codes.

    If I remember correctly LIRC was ported to the Palm Pilot, and if you could
    get it to work on a Palm III or similar device, there are lots of them in
    drawers just waiting for someone to ask for them.

    Geoff.
     
  5. Meat Plow

    Meat Plow Guest

    Toasters even had a 3.58 xtal in them. Phreakers were removing them and
    replacing the xtal in walkie talkies so they could mess with drive up
    window radio equipment for McDonalds, etc...
     
  6. N_Cook

    N_Cook Guest


    In the UK we were deprived of Cap'n Crunch 2600 Hz whistles and the phone
    routing system to go with it
     
  7. I remember visiting the UK in 1984 and trying to call back to the US. The only
    way to do it was to call the long distance operator and place a request for
    your call. When your turn came up, they would call you back.

    Trying to call from a pay phone at a rest stop on a motorway was a comedy
    routine straight out of Monty Python. The operator needed the area code
    and number of the phone I was calling from to place the call.

    In those days, there were no area codes on the phones themselves nor was there
    any marking on the phone as to where I was or the exchange it was on.
    All I knew was that I was at a rest stop a tour bus had made somewhere
    between London and Bath.

    Another time, I wantedto leave a message on an answering machine, as in
    "look up the EUROPEAN size you want and I'll call you from Paris when I
    can buy it". After ten minutes of standing at a pay phone in a B&B, the
    oeprator finaly got through and as soon as he heard the recording, he
    hung up.

    Geoff.
     
  8. Meat Plow

    Meat Plow Guest

    I could whistle at 2600hz and hang up the central opertator line. I made a
    blue box for a friend but he got busted before he used it. He was a greek
    with dual citizenship and had a girlfriend in Greece he would call using
    a reel to reel tape with some prerecorded tones on it. He got the idea
    from one of his greek buddies that was here visiting that built a working
    blue box and recorded the tones and their sequences on tape. The box was
    easy to build, all tin can 741 op amps on a self etched PC board. Problem
    was tuning it, I was only 17 back then and had no way to tune it. Said
    friend was set to take it to school electronics class and tune it when
    the FBI hauled him off one early morning in his boxer shorts :) He was
    deported back to Greece and lost his US citizenship.
     
  9. Sigh. The ceramic resonators were used as a chroma trap. Quartz
    This is basically backwards. The US had high quality, phase-linear
    transmission systems. Europe did not. The problem with NTSC was sloppy
    studio standards.
     
  10. Meat Plow

    Meat Plow Guest

    They found out in part by talking to his girlfriend. She explained that
    he used a tape device. I stayed at his place the night before so i was
    there at 6 am Sunday morning when they came a knockin on his door. I was
    zipped up in a sleeping bag peering through an opening when he answered
    the door (had a safety chain) opening it part way just enough for an arm
    holding a gold badge to pop through :) I stayed in the bag while they
    looked for a tape device which he didn't have there at the time. They
    found a loop of tape on an Echoplex tape delay box for guitar that he had
    and un-looped it with a pencil thinking they found the evidence :) They
    asked him who was inside the sleeping bag and he said just a friend and
    they never bothered me. He had hid the blue box pretty well and it wasn't
    found because they found the tape quickly so they were satisfied they had
    what they were looking for. When they left I dug out the blue box and
    destroyed it. Since they really had no evidence of a device that could
    make the calls but knowing the calls came from his number back when he
    was living with his parents they could only deport him and revoke his
    citizenship. He never went on trial for the calls. Just was given a plane
    ticket and said see ya later. They probably made it impossible to get a
    visa back into the country since I never saw him again. But he did call me
    maybe 10 years later from Greece. He said he was in a friends recording
    studio. That was in 1982.
     
  11. Meat Plow

    Meat Plow Guest

    Lots of TV programming was not in color here until 1967. I remember an
    old Soap called Dark Shadows. I remember when they first started airing
    in color. Must have had problems because they when between B&W and color
    almost every other daily episode for weeks.
     
  12. N_Cook

    N_Cook Guest


    So was that Allen Funt who televised the assignation between JFK and Marilyn
    Munroe?
     
  13. Grant

    Grant Guest

    I thought he kept them secret? --'^^^^^^^^^^^ Freudian slip?

    Wonderful what slips a careless spellcheck will show ;)

    Grant.
     
  14. Meat Plow

    Meat Plow Guest

    Bwahahahah I loved that show when it was on.
     
  15. Meat Plow

    Meat Plow Guest

    I remember that day as well as I do 911. Us kids were having a 'circus'
    in a neighbor's back yard. I went home to get something, forget what it
    was, and my mom was pissed off and crying and told me I couldn't have
    what I wanted because the pres had just been shot. That was Nov 22 of 63
    so we must have been experiencing global warming back then if it was warm
    enough to play outside with normal clothing as I remember.
     
  16. N_Cook

    N_Cook Guest

    Many universal remotes need to know what KIND of box
    before the code search works. It helps to know the
    corporate entity that built the box (for instance, TiVO
    responds to Philips satellite converter box commands,
    because some Philips satellite converters were TiVO
    equipped). And some of my Apple computers responded
    to (? Samsung or Goldstar) TV codes. It seems odd that TV
    codes operated the FM radio in a desktop computer.

    reply

    There is a collation of a lot of useful background info links off this page,
    I'm gradually wading through
    http://www.educypedia.be/electronics/televisionrc5.htm
    but linkages between makers seems a route to take.
    But I still get the impression that types of kit whether air conditioners or
    PVRs or whatever seem to have related structures of coding within the group
    rather than by maker
     
  17. Arfa Daily

    Arfa Daily Guest


    In 1984 in the UK, you could direct dial any country in the world. I worked
    for an American company then, and was on the phone to them in California
    from our UK office virtually every day, as well as to our offices in France,
    Germany and Holland, and customers in other countries. There were some
    restrictions on direct dialling from payphones, and maybe trans-continental
    was one of them, I don't remember for sure. If you could not find an area
    code and exchange on a payphone, then either it was *extremely* badly
    vandalised, or you weren't looking in the right place. Most had the phone
    box's details, including geographical location, area code, number and
    exchange, behind an armoured glass plate, mounted on the wall. The number
    and area code should also have been on the phone itself, if it was a dialup
    type, but this was admittedly often missing.

    Arfa
     
  18. that's amusing.

    in the early 90s I recall red boxes still worked in some parts of Chicago.

    You'd frequently get an operator who would ask something scripted like
    "are you using an illegal dialing device?" and then they'd keep requesting
    that you add quarter to the payphone.

    They'd even ask you to "please wait by the phone" if you just kept jamming
    on * and 6 or whatever the buttons were emulating a quarter.
     
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