Seven-segment 4-bit circuit

Discussion in 'General Electronics Chat' started by JohnZo, Jul 25, 2010.

  1. JohnZo

    Thread Starter New Member

    Jul 25, 2010
    I'm looking for a simple (simple == basic logic gates only) circuit diagram for a seven-segment display that will display values between 0 and F. The only way I can think of I can do this is setting up a Karnaugh map for each segment, which takes way too much work. There ought to be some ready circuits, but I can't find anything.
    Last edited: Jul 25, 2010
  2. tom66

    Senior Member

    May 9, 2009
  3. Wendy


    Mar 24, 2008
    You could start with an existing decoder, and add the logic for A-F.

    Or you could program a PIC or some other µC for the job.

    You could also use a EEPROM, or a PROM.

    I tend to agree, it is odd that no one has taken the extra step to cover the extra digits over the years. It would still be very friendly for 0-9 decoding, the pinouts would be the same, just a little extra internal logic.
  4. Ghar

    Active Member

    Mar 8, 2010
    Maybe it doesn't help but the K-maps aren't such a big deal, I've done it for 0-9 and it fit on one or two pages.
    Building it out of discrete logic chips... that's where the awful work will be.
  5. JohnZo

    Thread Starter New Member

    Jul 25, 2010
    Well, I did the K-maps and it wasn't so bad. But as soon as I finished the last segment, I searched once more and found this:
    (Though it has lots of duplicate gates.)
    Tomorrow I'll implement the display using my solution, with cleaned up gates, and post the result, perhaps someone might need it.