In today’s embedded landscape, graphical user interfaces (GUIs) are no longer an optional, they’re a necessity, even resource-constrained microcontrollers. This whitepaper explores how LVGL (Light and Versatile Graphics Library) and Zephyr RTOS together enable rich, responsive GUIs on devices like the ESP32-S3, without compromising performance or scalability.  

LVGL is an open-source graphics library optimized for low-resource embedded environments. It supports animations, customizable widgets, and touch inputs, all within a minimal memory footprint. Zephyr RTOS complements LVGL by offering a scalable, vendor-neutral platform with built-in support for over 800+ boards, including native drivers for displays and touch controllers.  

This whitepaper walks through a real-world implementation: building a GUI on an ESP32-S3 using a 4.0″ ST7796S TFT display and FT5336 capacitive touch controller. It covers everything from hardware setup and driver configuration to writing and flashing the application using Zephyr’s build system.  

Whether you’re developing consumer electronics, industrial HMIs, or IoT interfaces, this guide demonstrates how LVGL and Zephyr can accelerate your development cycle while maintaining modularity and portability.