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Espressif (ESP32 Chip Series)

LVGL can be used and configured as standard ESP-IDF component.

If you are new to ESP-IDF, follow the instructions in the ESP-IDF Programming guide to install and set up ESP-IDF on your machine.

LVGL Demo Projects for ESP32

For a quick start with LVGL and ESP32, the following pre-configured demo projects are available for specific development boards:

Refer to the README.md files in these repositories for build and flash instructions.

These demo projects use Espressif's Board Support Packages (BSPs). Additional BSPs and examples are available in the esp-bsp repository.

Using LVGL in Your ESP-IDF Project

The simplest way to integrate LVGL into your ESP-IDF project is via the esp_lvgl_port component. This component, used in the demo projects mentioned above, provides helper functions for easy installation of LVGL and display drivers. Moreover, it can add support for touch, rotary encoders, button or USB HID inputs. It simplifies power savings, screen rotation and other platform specific nuances.

The esp_lvgl_port supports LVGL versions 8 and 9 and is compatible with ESP-IDF v4.4 and above. To add it to your project, use the following command:

idf.py add-dependency "espressif/esp_lvgl_port^2.3.0"

By default, esp_lvgl_port depends on the latest stable version of LVGL, so no additional steps are needed for new projects. If a specific LVGL version is required, specify this in your project to avoid automatic updates. LVGL can also be used without esp_lvgl_port, as described below.

Obtaining LVGL

LVGL is distributed through ESP Registry, where all LVGL releases are uploaded. In case you do not want to use esp_lvgl_port, you can add LVGL component into your project with following command:

idf.py add-dependency lvgl/lvgl^9.*

Adjust the ^9.* part to match your LVGL version requirement. More information on version specifications can be found in the IDF Component Manager documentation. During the next build, the LVGL component will be fetched from the component registry and added to the project.

Advanced usage: Use LVGL as local component

For LVGL development and testing, it may be useful to use LVGL as a local component instead of from the ESP Registry, which offers only released versions and does not allow local modifications. To do this, clone LVGL to your project with the following command:

git submodule add https://github.com/lvgl/lvgl.git components/lvgl

Note

All components from ${project_dir}/components are automatically added to build.

Configuration

To configure LVGL, launch the configuration menu with idf.py menuconfig in your project root directory. Navigate to Component config and then LVGL configuration.

Support for Display and Touch Drivers

For successful LVGL project you will need a display driver and optionally a touch driver. Espressif provides these drivers that are built on its esp_lcd component.

These components share a common public API, making it easy to migrate your projects across different display and touch drivers.

To add a display or touch driver to your project, use a command like:

Using the File System under ESP-IDF

ESP-IDF uses the standard C functions (fopen, fread) in all storage related APIs. This allows seamless interoperability with LVGL when enabling the LV_USE_FS_STDIO configuration. The process is described in details below, using SPIFFS as demonstration.

  • Decide what storage system you want to use

    ESP-IDF has many, ready-to-use examples like SPIFFS , SD Card and LittleFS .

  • Re-configure your own project

    The example project should be examined for details, but in general the changes involve:

    • Enabling LVGL's STDIO file system in the configuration

      You can use menuconfig:

      • Component config → LVGL configuration → 3rd Party Libraries: enable File system on top of stdio API

      • Then select Set an upper cased letter on which the drive will accessible and set it to 65 (ASCII A)

      • You can also set Default driver letter to 65 to skip the prefix in file paths.

    • Modifying the partition table

      The exact configuration depends on your flash size and existing partitions, but the new final result should look something like this:

      nvs,      data, nvs,     0x9000,  0x6000,
phy_init, data, phy,     0xf000,  0x1000,
factory,  app,  factory, 0x10000, 1400k,
storage,  data, spiffs,         ,  400k,

      Note

      If you are not using a custom parition.csv yet, it can be added via menuconfig (Partition Table → Partition Table → Custom partition table CSV).

    • Apply changes to the build system

      Some ESP file systems provide automatic generation from a host folder using CMake. The proper line(s) must be copied to main/CMakeLists.txt

      Note

      LittleFS has extra dependencies that should be added to main/idf_component.yml

  • Prepare the image files

    LVGL's LVGLImage.py Python tool can be used to convert images to binary pixel map files. It supports various formats and compression.

    Meanwhile 3rd party libraries (like LodePNG and Tiny JPEG) allow using image files without conversion.

    After preparing the files, they should be moved to the target device:

    • If properly activated a SPIFFS file system based on the spiffs_image folder should be automatically generated and later flashed to the target

    • Similar mechanism for LittleFS uses the flash_data folder, but it's only available for Linux hosts

    • For the SD Card, a traditional file browser can be used

  • Invoke proper API calls in the application code

    The core functionality requires only a few lines. The following example draws the image as well.

    #include "esp_spiffs.h"

void lv_example_image_from_esp_fs(void) {

   esp_vfs_spiffs_conf_t conf = {
      .base_path = "/spiffs",
      .partition_label = NULL,
      .max_files = 5,
      .format_if_mount_failed = false
   };

   esp_err_t ret = esp_vfs_spiffs_register(&conf);

   if (ret != ESP_OK) {
      ESP_LOGE(TAG, "Failed to register SPIFF filesystem");
      return;
   }

   lv_obj_t * obj = lv_image_create(lv_screen_active());
   lv_image_set_src(obj, "A:/spiffs/logo.bin");
   lv_obj_center(obj);
}

  • Build and flash

    After calling idf.py build flash the picture should be displayed on the screen.

Note

Changes made by menuconfig are not being tracked in the repository if the sdkconfig file is added to .gitignore, which is the default for many ESP-IDF projects. To make your configuration permanent, add the following lines to sdkconfig.defaults:

CONFIG_PARTITION_TABLE_CUSTOM=y
CONFIG_LV_USE_FS_STDIO=y
CONFIG_LV_FS_STDIO_LETTER=65
CONFIG_LV_LV_FS_DEFAULT_DRIVE_LETTER=65