Files
tactility/Modules/lvgl-module
Adolfo Reyna e29e9b4a66 feat(rlcd): runtime font size selector in Settings->Display
- device.properties bump default to 20
- lvgl_fonts add runtime override API (g_runtime_font_size + externs for all Montserrat sizes)
- DisplaySettings add fontSize field persisted in properties
- Display app adds Font size dropdown 14-28 applying immediately
- Lvgl.cpp applies saved runtime font on boot
- device.py new bucket <=20 includes all fonts for runtime switching (~150KB)

Co-authored-by: internal-model
2026-07-18 15:10:42 -04:00
..
2026-06-03 23:10:37 +02:00
2026-06-03 23:10:37 +02:00

lvgl-module

This module manages the lifecycle of the LVGL library within the Tactility ecosystem.

What the library does

The lvgl-module provides:

  • Lifecycle Management: Handles initialization and termination of the LVGL library.
  • Task Management: Manages the LVGL main loop task.
  • Thread-Safety: Provides mutex-based locking mechanisms (lvgl_lock, lvgl_unlock) to ensure safe access to LVGL APIs from multiple tasks.
  • Font Access: Provides a unified interface to access pre-configured text and icon fonts.

Different types of fonts

The module supports two main categories of fonts:

Text Fonts

Standard text rendering uses the Montserrat font. Three sizes are pre-configured:

  • FONT_SIZE_SMALL
  • FONT_SIZE_DEFAULT
  • FONT_SIZE_LARGE

Icon Fonts

Icons are provided by the Material Symbols font, divided into three usage-specific sets:

  • Statusbar Icons: Optimized for the system status bar.
  • Launcher Icons: Sized for application launchers.
  • Shared Icons: General purpose icons used across the system.

How to update the fonts

Font sizes and symbols are configurable:

  • On ESP32 (IDF): Sizes can be updated via menuconfig or by editing sdkconfig. Look for CONFIG_TT_LVGL_FONT_SIZE_* and CONFIG_TT_LVGL_*_ICON_SIZE parameters.
  • On Simulator/POSIX: Default sizes are defined in Modules/lvgl-module/CMakeLists.txt.

If you change an icon font size, ensure that a corresponding C file exists in source-fonts/ (e.g., material_symbols_shared_24.c). These files are generated from TTF/OTF fonts using the LVGL font converter.

License

This module is licensed under the Apache v2.0 license.