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Universal Infra Red control

Discussion in 'Electronic Repair' started by N_Cook, Jul 12, 2009.

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  1. N_Cook

    N_Cook Guest

    I'm aware of
    LIRC - linux infrared remote control project
    a/ over the decades I've learnt and forgotten Fortran, CP/M, various
    flavours of DOS, win 3.1 etc and don't really wish to have to learn another.
    b/ Still needs a hardware implementation for a r/c for a piece of kit rather
    than tying up a learning mode "universal" r/c. So I intend playing with some
    4000 CMOS series, monostables with 10 turn pots, counters and thumbwheel
    switches for a proper universal IR transmitter.

    Looking at the LIRC archive there seems to be specious accuracy in the
    figures, AFAIK 10 percent timing error-band is about the norm for domestic
    r/c (not complex ones) so they can use ceramic resonators rather than
    eg LIRC gap 46,229 uSec for their particular one tested, scope trace of
    order 45uS +/- 1 uSec below , I'm assuming is the complete block repeat

    Starting from a known quantity for a JVC r/c, I have sitting around, can
    anyone cross-correlate the LIRC data to oscillscope trace view.
    From LIRC archive for r/c
    name JVC_PQ21953F

    bits 16
    eps 30
    aeps 100

    header 8488 4126
    one 590 1508
    zero 590 462
    ptrail 590
    gap 46229
    min_repeat 2
    toggle_bit 0

    begin codes
    # setting A-VCR
    operate 0x000000000000C2D0

    for the "operate" button only , for simplicity here


    From scope simple timings/accuracy without using a frequency counter , but
    could do so if more accuracy is required
    carrier frequency 40KHz , 25uS period
    full code repeats after 45uS
    code pulses of order 0.5mS to 0.6mS duration
    ident code at 0,2,4,5,6,7,8 mS ie 101011111 (same for all button pushes)
    "operate" code starts at 10mS and code reads
    1101011011111 as on the screen ie first on the left
    (varies on button pushed )
    I could not find the meaning of eps , aeps, ptrail etc
    Whatever way of, reading/inverting/adding unseen zeros, the scope-read
    "operate" pattern, I cannot get hex code C2D0
  2. N_Cook

    N_Cook Guest

  3. N_Cook

    N_Cook Guest

    I would have thought that somewhere out there would be a schematic for a
    universal r/c transmitter for exercising / hacking r/c-absent equipment.
    There are 2 "operate" codes for that JVC r/c one, I relayed before was for
    the TV setting and
    for VCR setting but I cannot turn that into hex C2D0 either, with lost
    the ident code is the same
  4. N_Cook

    N_Cook Guest

    The 2 "operate" codes were
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