lvgl/README.md

# Littlev Graphics Libraray

![LittlevGL cover](http://www.gl.littlev.hu/home/main_cover_small.png)

LittlevGL provides everything you need to create a Graphical User Interface (GUI) on embedded systems with easy-to-use graphical elements, beautiful visual effects and low memory footprint.

Homepage: http://www.gl.littlev.hu

### Table Of Content
* [Key features](#key-features)
* [Porting](#porting)
* [Project set-up](#project-set-up)
* [PC simulator](#pc-simulator)
* [Contributing](#contributing)
* [Donate](#donate)

## Key features
- Powerful building blocks buttons, charts, lists, sliders, images etc
- Advanced graphics with animations, anti-aliasing, opacity, smooth scrolling
- Various input devices touch pad, mouse, keyboard and external buttons
- Multi language support with UTF-8 support
- Fully customizable graphical elements

- Hardware independent to use with any microcontroller or display
- Scalable to operate with few memory (80 kB Flash, 10 kB RAM)
- OS, External memory and GPU supported but not required
- Single frame buffer operation even with advances graphical effects

- Written in C for maximal compatibility
- PC simulator to develop without embedded hardware
- Tutorials, examples, themes for rapid development
- Advanced support and professional GUI development service
- Documentation and API references online
- Free and open source under MIT licence

## Porting
In the most sime case you need 4 things:
1. Call `lv_tick_inc(1)` in every millisecods in a Timer or Task
2. Register a function which can **copy a pixel array** to an area of the screen
3. Register a function which can **read an input device**. (E.g. touch pad)
4. Call `lv_task_handler()` periodically in every few milliseconds ()

For more information visit http://www.gl.littlev.hu/porting
 
## Project set-up
1. **Clone** or download the lvgl repository: `git clone  https://github.com/littlevgl/lvgl.git`
2. **Create project** with your prefered IDE and add the *lvgl* folder
3. Copy **lvgl/lv_conf_templ.h** as **lv_conf.h** next to the *lvgl* folder
4. In the *_conf.h files delete the first `#if 0` and its `#endif`. Let the default configurations at first.
5. In your *main.c*: #include "lvgl/lvgl.h"   
6. In your *main function*:
   * lvgl_init();
   * tick, display and input device initialization (see above)
7. To **test** create a label: `lv_obj_t * label = lv_label_create(lv_scr_act(), NULL);`  
8. In the main *while(1)* call `lv_task_handler();` and make a few milliseconds delay (e.g. `my_delay_ms(5);`) 
9. Compile the code and load it to your embedded hardware

## PC Simulator
If you don't have got an embedded hardware you can test the graphics library in a PC simulator. The simulator uses [SDL2](https://www.libsdl.org/) to emulate a display on your monitor and a touch pad with your mouse.

There is a pre-configured PC project for **Eclipse CDT** in this repository: https://github.com/littlevgl/pc_simulator

## Contributing
See [CONTRIBUTING.md](https://github.com/littlevgl/lvgl/blob/master/docs/CONTRIBUTING.md)

## Donate
If you are pleased with the graphics library and found it useful please support its further development:

[![Donate](https://www.paypalobjects.com/en_US/i/btn/btn_donateCC_LG.gif)](https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=GJV3SC5EHDANS)