More Pi Outputs with 74HC595
Warren Gay · Apress eBooks · 2017
Like input GPIOs in Chapter 9, the application designer may require more GPIO outputs. Because this 74HC595 part is a member of the “HC” logic family, it is able to operate with a VCC ranging from 2.0 to 6.0 volts. This is perfect for operating under the 3.3V Raspberry Pi and costs less than a dollar at digikey.com. Figure 10-1 illustrates a chip that I’ve used.