* PXP: Added basic PXP acceleration PXP accelerated features: - fill (+ opacity) - BLIT (+ opacity) - recoloring (+ opacity) - color keying (+ opacity) Recoloring + color keying simultaneously not supported. Signed-off-by: Jozef Bastek <jozef.bastek@nxp.com> * PXP: Added abstraction for interrupt handling Previous imlpementation used IRQ polling on PXP, which doesn't allow real CPU offload. Therefore added set of callbacks for interrupt handling that should be implemented by user, with possible RTOS integration. Default/example implementation of callbacks for bare metal and FreeRTOS provided (lv_gpu_nxp_pxp_osa.c), enabled by LV_USE_GPU_NXP_PXP_DEFAULT_OSA switch, accesible via pxp_default_cfg structure. Signed-off-by: Jozef Bastek <jozef.bastek@nxp.com> * PXP: Optimized cache flushing Previous implementation flushed areas of (LCD width * object height) size. Cache flush is expensive operation and flushing line by line, smallest possible area, boost performance by shortening time spent on cache flushes. Signed-off-by: Jozef Bastek <jozef.bastek@nxp.com> * PXP: Added documentation for NXP PXP accelerator Signed-off-by: Jozef Bastek <jozef.bastek@nxp.com> * PXP: added missing extern c in header files Signed-off-by: Jozef Bastek <jozef.bastek@nxp.com> * PXP: Fixed ifdefs - Removed LV_USE_GPU, fixed internal config LV_USE_GPU is not intended as a global GPU enable switch. It's used only for gpu_blend_cb and gpu_fill_cb callbacks, which are obsolete. This patch removes LV_USE_GPU dependency for PXP code, so it's enabled only with LV_USE_GPU_NXP_PXP symbol. Added missing symbols to internal conf, so automatic testd can pass build step. Signed-off-by: Jozef Bastek <jozef.bastek@nxp.com> * PXP: Default OSA changed to PXP auto-initialization Auto init feature added so if user run FreeRTOS or bare-metal, no PXP Init code is required. Renamed symbol to be more clear. Signed-off-by: Jozef Bastek <jozef.bastek@nxp.com> * PXP: Documentation moved to docs repo Signed-off-by: Jozef Bastek <jozef.bastek@nxp.com> * PXP: Fixed alpha configuration - Coverity issue: AS blend config used uninitialized structure. No impact on functionality, as blend module is not used (porter-duff blends in this case) - Alpha config fixed - swapped alpha values produced different result from SW render Signed-off-by: Jozef Bastek <jozef.bastek@nxp.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 · 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 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.

