Strongly recommended · for beginners
How Shift Registers Work!
Why people recommend it
A clear explanation of how a 74HC595 shift register works and how to drive many LEDs from a few Arduino pins.
Watch for: Around eleven minutes; pin names differ on other driver chips
In their words
This is the tutorial I use to understand shift registers: [video], and the one that uses SPI is nXl4fb_LbcI
Dan Chaltiel on arduino.stackexchange.com, Aug 2015. CC BY-SA.
