Connecting the 74HC595N shift register to control many LEDs

So far, we've been controlling LEDs with individual GPIO pins. Not only is this a rather inefficient use of the Raspberry Pi Zero GPIO, but even if we used every single available pin for an LED, that would be a pretty boring light show. Instead, by adding in an LED driver such as the inexpensive 74HC595N, you easily get the ability to leverage several LEDs, or multiple 4x7-segment-number displays. In this recipe, we will use the SPI interface to control an eight-LED array. Let's get cooking!

Getting ready

Here is what you'll need for this recipe. At this point, you should be able to improvise with LED options. I used the 74HC595N, which is a commonly available chip online and also included in Elegoo's Super Complete Starter Kit.

• Eight 330 Ohm resistors

• One 74HC595N LED driver

• Eight LEDs, any color you want

• Jumper cables, breadboard, cobbler

• We will also be using the PiShiftPy library, available on pip:

        sudo pip install PiShiftPy
  

How...