Re: COMPONENT REQUEST: display using 1x 74HC595 and configurable 7-segments digits with multiplexing
Posted: Thu Feb 12, 2026 4:08 am
Hi
Looked at the datasheet for your register (briefly) and if only driving LEDs it seems a bit overkill, being designed to handle inductive loads such as relays and high power loads. A single segment of a LED would struggle to pull a fraction of its rating.
It appears it could indeed be driven by only three lines, but I'm not seeing any reason so far to not just use one of the already supported shift-registers instead. Although all four Digits are connected to the chip, due to multiplexing only one segment of one digit at a time will ever be illuminated.
Personally I'd use one of the supported shift registers and in the "update" routine include direct control of L1 - L3.
Regards
Looked at the datasheet for your register (briefly) and if only driving LEDs it seems a bit overkill, being designed to handle inductive loads such as relays and high power loads. A single segment of a LED would struggle to pull a fraction of its rating.
It appears it could indeed be driven by only three lines, but I'm not seeing any reason so far to not just use one of the already supported shift-registers instead. Although all four Digits are connected to the chip, due to multiplexing only one segment of one digit at a time will ever be illuminated.
Personally I'd use one of the supported shift registers and in the "update" routine include direct control of L1 - L3.
Regards