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7 segment LED display to serial data stream — Parallax Forums

7 segment LED display to serial data stream

ArchiverArchiver Posts: 46,084
edited 2002-10-24 19:08 in General Discussion
Hi everyone, I would like to know if this crazy idea of mine is
possible.

At work I have a master time clock and several "slave" clocks that
receive a proprietary signal from the master clock. My boss would
like me to design some cheaper slave clocks (less than $850ea) than
what we currently pay.

I was thinking of hacking one of the 6 digit LED clock displays
(HH,MM,SS) and "splitting" the display to three rooms. Is there a
chip that will reverse the LED display-i.e. take the individual
segment signals and convert them into a BCD or serial signal that can
then be rebuilt at each of the slave clocks and then drive the 7
segment LED displays?

I was thinking of just paralleling the displays, but running 42+ (7x6)
signal lines and associated line buffers, etc. for 50 ft does not
sound like much fun.

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2002-10-23 03:06
    Check out the 74C915. Dunno if its still available though.

    Jack

    mcgyver272000 wrote:
    >
    > Hi everyone, I would like to know if this crazy idea of mine is
    > possible.
    >
    > At work I have a master time clock and several "slave" clocks that
    > receive a proprietary signal from the master clock. My boss would
    > like me to design some cheaper slave clocks (less than $850ea) than
    > what we currently pay.
    >
    > I was thinking of hacking one of the 6 digit LED clock displays
    > (HH,MM,SS) and "splitting" the display to three rooms. Is there a
    > chip that will reverse the LED display-i.e. take the individual
    > segment signals and convert them into a BCD or serial signal that can
    > then be rebuilt at each of the slave clocks and then drive the 7
    > segment LED displays?
    >
    > I was thinking of just paralleling the displays, but running 42+ (7x6)
    > signal lines and associated line buffers, etc. for 50 ft does not
    > sound like much fun.
    >
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  • ArchiverArchiver Posts: 46,084
    edited 2002-10-23 03:28
    Thanks for your help, Jack.

    Boy, a six minute response-must be a record! I was able to find a
    manufacturer in the Netherlands, but I was hoping for one in the US.

    I may need to rethink my crazy idea.

    If I could only get the clock data format, I could have a stamp decode
    the data.

    --- In basicstamps@y..., goflo@p... wrote:
    > Check out the 74C915. Dunno if its still available though.
    >
    > Jack
  • ArchiverArchiver Posts: 46,084
    edited 2002-10-23 18:47
    mcgyver272000 wrote:
    > ...
    > If I could only get the clock data format, I could have a stamp decode
    > the data.

    Not sure sure you need to - Most displays are multiplexed, and
    have a sync (aka "clock") pulse so the controller can distinguish
    valid data. The sync could be used to step the remote display.
    You'd need a way to initialize the remote display, after which the
    remote simply increments the count each sync from the master...

    Jack
  • ArchiverArchiver Posts: 46,084
    edited 2002-10-24 19:08
    Sorry, I wasn't very clear on which signals I want to decode.

    The slave clock is used in a tv studio master clock system. There is
    an unbalanced cable connecting all slave units to the master unit.

    Instead of having each slave clock decode the data sent by the master
    clock, I was hoping to have several displays that would use one
    "time/date decoder" and then connect multiple display units to the
    decoder. The units are manufactured by ESE and use "ESE time code
    TC90(tm)" formated data. I was hoping to decode the TC90 signal with
    the stamp.

    --- In basicstamps@y..., goflo@p... wrote:
    > Not sure sure you need to - Most displays are multiplexed, and
    > have a sync (aka "clock") pulse so the controller can distinguish
    > valid data. The sync could be used to step the remote display.
    > You'd need a way to initialize the remote display, after which the
    > remote simply increments the count each sync from the master...
    >
    > Jack
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