74HC595 8-Bit Serial-to-Parallel Shift Register IC (DIP-16)

Running out of digital output pins is one of the most common walls a project hits once it grows past driving a handful of LEDs, and the 74HC595 is the classic fix, letting a microcontroller shift eight bits of output data in serially over just three pins and latch them out in parallel. Multiple chips chain together easily, so a single three-pin connection can ultimately control dozens of outputs across several chained 74HC595s, which is exactly how larger LED arrays and multi-digit 7-segment displays are commonly driven. As a bare DIP-16 chip rather than a pre-soldered breakout board, this suits builders prototyping the wiring themselves on a breadboard or designing it directly into a custom PCB rather than reaching for an off-the-shelf module.