Quad 7seg with 595s: standard methods?

Discussion in 'Embedded Systems and Microcontrollers' started by donryanocero, Apr 19, 2013.

  1. donryanocero

    Thread Starter New Member

    Apr 16, 2013
    Hey! I have a 4 digit 7 segment display wired to 4 daisy chained 595s for use with an AVR uC. I wired the digits to the 595 outputs more or less randomly, and it works fine, but is there a standard method of connecting these, as in Qa goes to center bar, Qb top left, etc.

    Mine are all the same between the digits, but I figured I don't want to solder it all up to find out it's a weird config.

    Also: Least significant digit should probably be on the far right? I have this backwards since i started with 'digit 1' on the data sheet.

    Thanks in advance for the pointers!

  2. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    I would connect mine so seg A goes to bit 0, seg B to bit 1, thru seg G to bit 6 and DP to bit 7. That's easy to remember for the time I'm making my array decoder for number to segments.

    I don't follow what the digit number you use are.
  3. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    I connect them in whatever way the wiring and PCB tracks work out the neatest. As long as all 4 digits are the same as each other! :)

    Then I use a lookup table for the 0-9 values and which segments light up.
  4. takao21203

    AAC Fanatic!

    Apr 28, 2012
    I must say lately I only route IO 1:1 and sort it out with a decoding table.
    For instance for a 3digit LCD, I use 5 bytes for each number.
    It is split over various ports.

    It is a lot of writing work, normally takes up 2 A4 pages.