My question is can I add as 74HC595 shift registry to drive the 8 pins so i can use in total only 7 pins instead of 12 ?
Meaning: 4 for anode select and 3 for shift register control [data, clock, /OE] ?
The display will be blinking?
The anodes will have to be strobed
Many other display have a common anode:
Is it possible to use 74HC595 also for common anode ?
By sending LOWs/0s (as data) for ONs
Attached is the circuitry for a 2-digit display.
It's a lot less trouble to use 4 discrete 7-segment displays with a separate shift register for each ("daisy-chained") - you don't have to repeatedly tend to the strobing chore, you just shift out your data and go on with life.