LVGL Example#

Overview#

This example demonstrates how to use LVGL (Light and Versatile Graphics Library) on K230. LVGL is a free and open-source embedded graphics library that provides rich widgets, smooth animation effects, and support for multiple input devices, and is suitable for both MCU and MPU platforms.

Feature Summary#

LVGL Capabilities Demonstrated#

Multi-resolution display support
Touch-screen input integration
Common UI widgets such as labels, buttons, bars, sliders, and switches
Responsive layout behavior
Double buffering and GSDMA-assisted display updates

Display Driver Notes#

The example is designed around the K230 display path and supports:

up to 1920x1080 display resolution
double buffering to reduce flicker
GSDMA-assisted image transfer

Input Device Notes#

capacitive or resistive touch input
gesture operations such as click and slide

Source Location#

Demo source path: src/rtsmart/examples/3rd-party/lvgl/lvgl_basic

Usage#

Build#

Firmware Build#

At the root of K230 RTOS SDK, use make menuconfig to enable the LVGL example in the firmware build, then build the firmware.

Standalone Build#

You can either enable the LVGL example in make menuconfig, or build it directly:

cd src/rtsmart/examples/3rd-party/lvgl/lvgl_basic
mkdir build && cd build
cmake ..
make

Hardware Preparation#

Connect a supported LCD panel
Connect a touch panel if touch input is required
Verify that the board-side display and touch wiring matches the sample configuration

Run#

Copy the built executable to the board, enter the target directory, then run:

./lvgl_basic

Expected Result#

After startup, the sample initializes the display, registers touch input if available, creates the LVGL demo UI, and starts the LVGL task loop. The screen shows content similar to:

Screen: 800x480
===========================
LVGL Multi-Resolution Demo

[Button 1] [Button 2] [Button 3]

Progress Bar:
[===========>       ] 70%

Slider:
[----O----]

Switch:
[ON]

UI characteristics:

the top area shows the current screen resolution
the middle area shows three buttons with different colors
the lower area shows a progress bar, slider, and switch
all widgets support touch interaction

You can interact with the interface through the touch screen:

tap the buttons to trigger responses
drag the slider to change the value
toggle the switch on and off

Custom UI#

LVGL provides rich APIs for building custom interfaces. For example:

// Create a label
lv_obj_t* label = lv_label_create(parent);
lv_label_set_text(label, "Hello LVGL!");

// Create a button
lv_obj_t* btn = lv_button_create(parent);
lv_obj_t* btn_label = lv_label_create(btn);
lv_label_set_text(btn_label, "Click Me");
lv_obj_center(btn_label);

// Create a progress bar
lv_obj_t* bar = lv_bar_create(parent);
lv_bar_set_value(bar, 50, LV_ANIM_OFF);

Tip

You can adjust many LVGL parameters in the lv_conf.h configuration file, such as memory size, screen resolution, and font selection. For detailed APIs and configuration options, refer to the LVGL official documentation.

Tip

LVGL requires periodic calls to lv_timer_handler() to refresh the UI. It is recommended to call this function regularly inside the main loop.

LVGL Example

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