OSS + ELC EU 2026

Pin multiplexing is always needed in embedded development. But when we start changing pins in a devicetree overlay, or when creating a custom board, things can quickly become confusing: build errors, wrong pin states, peripherals not starting, or hardware that simply does not behave as expected.

In Zephyr, the pinctrl subsystem is what connects the physical pins of the SoC with the peripherals we want to use. It defines the pin function, the electrical configuration, and the pin states used by the drivers.

In this talk, we will demystify pin multiplexing in Zephyr and explain how to use pinctrl in devicetree in simple words. We will go step by step through pin groups, pin states, common configurations, overlays, board files, and SoC-specific syntax.

We will also use practical examples for common peripherals and vendor families, and show how to debug the most frequent issues when customizing pins.