commit 06917a6ec3bfdf12b19aede3e6df06e66d681ed7 * fix(image decoder): fix memory leak when no decoder can be used and handle the out of memory gracefully * fix(image decoder): zero the output fields after each iteration to clean the stale info saved by try failed decoder and remove img_data zero from lv_img_decoder_built_in_open since it has be done in the loop Co-authored-by: Gabor Kiss-Vamosi <kisvegabor@gmail.com>
LVGL - Light and Versatile Graphics Library
LVGL provides everything you need to create embedded GUI with easy-to-use graphical elements, beautiful visual effects and low memory footprint.
Website · Online demo · Nightly demos · Docs · Forum
Features
- Powerful building blocks: buttons, charts, lists, sliders, images, etc.
- Advanced graphics: animations, anti-aliasing, opacity, smooth scrolling
- Use various input devices: touchscreen, mouse, keyboard, encoder, buttons, etc.
- Use multiple displays: e.g. monochrome and color display
- Hardware independent to use with any microcontroller or display
- Scalable to operate with little memory (64 kB Flash, 10 kB RAM)
- Multi-language support with UTF-8 handling, Bidirectional and Arabic script support
- Fully customizable graphical elements via CSS-like styles
- OS, External memory and GPU are supported but not required
- Smooth rendering even with a single frame buffer
- Written in C for maximal compatibility (C++ compatible)
- Micropython Binding exposes LVGL API in Micropython
- Simulator to develop on PC without embedded hardware
- Examples and tutorials for rapid development
- Documentation and API references
Requirements
Basically, every modern controller (which is able to drive a display) is suitable to run LVGL. The minimal requirements are:
Name | Minimal | Recommended |
Architecture | 16, 32 or 64 bit microcontroller or processor | |
Clock | > 16 MHz | > 48 MHz |
Flash/ROM | > 64 kB | > 180 kB |
Static RAM | > 2 kB | > 4 kB |
Stack | > 2 kB | > 8 kB |
Heap | > 2 kB | > 8 kB |
Display buffer | > 1 × hor. res. pixels | > 10 × hor. res. pixels |
Compiler | C99 or newer |
Note that the memory usage might vary depending on the architecture, compiler and build options.
Just to mention some platforms:
- STM32F1, STM32F3, STM32F4, STM32F7, STM32L4, STM32L5, STM32H7
- Microchip dsPIC33, PIC24, PIC32MX, PIC32MZ
- NXP: Kinetis, LPC, iMX, iMX RT
- Linux frame buffer (/dev/fb)
- Raspberry Pi
- Espressif ESP32
- Infineon Aurix
- Nordic NRF52 Bluetooth modules
- Quectel modems
Get started
This list shows the recommended way of learning the library:
- Check the Online demos to see LVGL in action (3 minutes)
- Read the Introduction page of the documentation (5 minutes)
- Get familiar with the basics on the Quick overview page (15 minutes)
- Set up a Simulator (10 minutes)
- Try out some Examples
- Port LVGL to a board. See the Porting guide or check the ready to use Projects
- Read the Overview page to get a better understanding of the library (2-3 hours)
- Check the documentation of the Widgets to see their features and usage
- If you have questions go to the Forum
- Read the Contributing guide to see how you can help to improve LVGL (15 minutes)
Examples
For more examples see the lv_examples repository.
Button with label
lv_obj_t * btn = lv_btn_create(lv_scr_act(), NULL); /*Add a button to the current screen*/
lv_obj_set_pos(btn, 10, 10); /*Set its position*/
lv_obj_set_size(btn, 100, 50); /*Set its size*/
lv_obj_set_event_cb(btn, btn_event_cb); /*Assign a callback to the button*/
lv_obj_t * label = lv_label_create(btn, NULL); /*Add a label to the button*/
lv_label_set_text(label, "Button"); /*Set the labels text*/
...
void btn_event_cb(lv_obj_t * btn, lv_event_t event)
{
if(event == LV_EVENT_CLICKED) {
printf("Clicked\n");
}
}
LVGL from Micropython
Learn more about Micropython.
# Create a Button and a Label
scr = lv.obj()
btn = lv.btn(scr)
btn.align(lv.scr_act(), lv.ALIGN.CENTER, 0, 0)
label = lv.label(btn)
label.set_text("Button")
# Load the screen
lv.scr_load(scr)
Contributing
LVGL is an open project and contribution is very welcome. There are many ways to contribute from simply speaking about your project, through writing examples, improving the documentation, fixing bugs to hosing your own project under in LVGL.
For a detailed description of contribution opportunities visit the Contributing section of the documentation.