TL;DR
KurtE and Merlin513 successfully ported a weather station application from the Arduino® GIGA™ R1, which features a powerful dual-core STM32H747XI microcontroller, to the more limited Arduino® UNO™ R4 WiFi board. The original app, built on ZephyrOS, showcased local weather data through a graphical user interface (GUI) on a touchscreen. The GIGA R1's robust processing capabilities allowed for a rich feature set, but the transition to the UNO R4 required significant optimization due to its single-core Renesas RA4M1 microcontroller, operating at just 48 MHz with only 32 kB of RAM.