There is a growing interest in Zephyr RTOS within the embedded community. Unlike Arduino or ESP-IDF, Zephyr gives you a real hardware abstraction layer that lets you write firmware once and compile it for completely different microcontrollers without changing a single line of application code. Think of it as bringing Linux-style portability to the embedded world. That's exactly what I wanted to put to the test. I have four Seeed Studio XIAO modules on my bench: the nRF52840, nRF54L15, ESP32-S3, and ESP32-C6 and while they all share the same tiny 21×17.8 mm footprint and pinout, their cores are completely different. My goal is to benchmark their real-world power consumption and execution times using a single Zephyr firmware that compiles for all of them,…