Microcontroller chips, like our own RP2040 on Raspberry Pi Pico, offer hardware support for protocols such as SPI and I2C. This allows them to send and receive data to and from supported peripherals.
But what happens when you want to use unsupported tech, or multiple SPI devices? That’s where Programmable I/O, or PIO, comes in. PIO was developed just for RP2040, and is unique to the chip.
PIO allows you to create additional hardware interfaces, or even new types of interface. If you’ve ever looked at the peripherals on a microcontroller and thought “I need four UARTs and I only have two,” or “I’d like to output DVI video,” or even “I need to communicate with this accursed serial device I found, but there is no hardware support anywhere,” then you will have fun with PIO.
We’ve put together this handy explainer to help you understand PIO and how it can be used to add more devices to your Raspberry Pi Pico.
For more information on PIO and RP2040, check out this article from HackSpace magazine.