Quad 7seg with 595s: standard methods?

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donryanocero

Joined Apr 16, 2013
3
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!

Ryan
 

ErnieM

Joined Apr 24, 2011
8,377
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.
 

THE_RB

Joined Feb 11, 2008
5,438
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.
 

takao21203

Joined Apr 28, 2012
3,702
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.
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.
 
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