Decoding to Hex for 7-seg Display

Discussion in 'General Electronics Chat' started by cldudley, Sep 25, 2010.

  1. cldudley

    Thread Starter New Member

    Oct 7, 2009
    Hi forum, I have a question for my new 8086 SBC project. I want to display the current values on the address and data bus when I am single-stepping the computer, but I really don't want to use a bunch of LEDs, I would rather have something like a 7-seg display to show the values in hex.

    I think what I am looking for are the TIL311 displays, as seen on Jameco here:

    I really don't want to pay $15 per display, when I will need like 10 of them to decode all of the signals I want. Is there a cheaper/easier way to do this?
  2. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    This would eliminate a lot of circuit building to interface standard LED Hex displays for display of a bus lines contents.

    Using the built in store, display support in the HEX display chip all you need to do is build a simple data buffer port, if your not already set up with a data port somewhere you might access.

    It would save lots of circuit building time and board room , that's about the only advantage I could see in using it. How much $ is a plain Jane Hex segmented display going for now-a-days? If the prices are comparable, this would be cheaper and less complicated.
  3. Markd77

    Senior Member

    Sep 7, 2009
  4. Markd77

    Senior Member

    Sep 7, 2009
    Failing that it would be easiest thing to do with a cheap micro. I think it could be done in about 30 instructions with a cheap PIC like the PIC16F505.
    Even with buying a programmer it would be cheaper than TIL311s.
    I'd be happy to write the code if you want to do it that way.
  5. sbombs


    Feb 26, 2010
    7447 does BCD - 7 Segment
    Dj Delorie of gEDA fame has his own
    I bet DJ makes his own electrons from scratch.

    But, I have to tell you that Binary to Hex conversion is very easily and quickly done visually. Even if you can't do math! Group the bits into groups of 4 bits. Write down, or memorize the table of

    0000 = 0
    0001 = 1
    0010 = 2
    1110 = E
    1111 = F

    example: 1011010111011010
    1011 0101 1101 1010
  6. marshallf3

    Well-Known Member

    Jul 26, 2010
    4511 is just BCD - decimal, didn't there used to be a BCD to full hex chip?

    0 1 2 3 4 5 6 7 8 9 A b C d E F
  7. Markd77

    Senior Member

    Sep 7, 2009
    Yes, the MC14495. Link to datasheet in post 3. It's most likely hard to find these days, but perfect for the job.
    sbombs likes this.