GPIO stands for General-Purpose Input/Output . GPIO pins don’t have fixed assignments, so under program control, they can perform many different tasks. In this chapter, you learn the specifics of the GPIO interface and are introduced to programs that can control devices connected to GPIO pins.
All Raspberry Pi models have GPIO connectors; all except the Pi Zero and Pi Zero W have pin headers that make connections very simple. The Pi Zero and Pi Zero W have open holes that can be used for soldered-in-place GPIO interfaces.
