1<h1 align="center"> LVGL - Light and Versatile Graphics Library</h1>
2
3<p align="center">
4<img src="https://lvgl.io/assets/images/img_1.png">
5</p>
6
7<p align="center">
8LVGL provides everything you need to create embedded GUI with easy-to-use graphical elements, beautiful visual effects and low memory footprint.
9</p>
10
11<h4 align="center">
12<a href="https://lvgl.io">Website </a> &middot;
13<a href="https://lvgl.io/demos">Online demo</a> &middot;
14<a href="https://docs.lvgl.io/">Docs</a> &middot;
15<a href="https://forum.lvgl.io">Forum</a>
16</h4>
17
18---
19
20## Features
21* Powerful [building blocks](https://docs.lvgl.io/latest/en/html/widgets/index.html): buttons, charts, lists, sliders, images, etc.
22* Advanced graphics: animations, anti-aliasing, opacity, smooth scrolling
23* Use [various input devices](https://docs.lvgl.io/latest/en/html/overview/indev.html): touchscreen, mouse, keyboard, encoder, buttons, etc.
24* Use [multiple displays](https://docs.lvgl.io/latest/en/html/overview/display.html): e.g. monochrome and color display
25* Hardware independent to use with any microcontroller or display
26* Scalable to operate with little memory (64 kB Flash, 10 kB RAM)
27* Multi-language support with UTF-8 handling, Bidirectional and Arabic script support
28* Fully customizable graphical elements via [CSS-like styles](https://docs.lvgl.io/latest/en/html/overview/style.html)
29* OS, External memory and GPU are supported but not required
30* Smooth rendering even with a [single frame buffer](https://docs.lvgl.io/latest/en/html/porting/display.html)
31* Written in C for maximal compatibility (C++ compatible)
32* Micropython Binding exposes [LVGL API in Micropython](https://blog.lvgl.io/2019-02-20/micropython-bindings)
33* [Simulator](https://docs.lvgl.io/latest/en/html/get-started/pc-simulator.html) to develop on PC without embedded hardware
34* [Examples](lv_examples) and tutorials for rapid development
35* [Documentation](http://docs.lvgl.io/) and API references
36
37## Requirements
38Basically, every modern controller (which is able to drive a display) is suitable to run LVGL. The minimal requirements are:
39
40<table>
41  <tr>
42    <td> <strong>Name</strong> </td>
43    <td><strong>Minimal</strong></td>
44    <td><strong>Recommended</strong></td>
45  </tr>
46  <tr>
47    <td><strong>Architecture</strong></td>
48    <td colspan="2">16, 32 or 64 bit microcontroller or processor</td>
49  </tr>
50  <tr>
51    <td> <strong>Clock</strong></td>
52    <td> &gt; 16 MHz </td>
53    <td> &gt; 48 MHz</td>
54  </tr>
55
56  <tr>
57    <td> <strong>Flash/ROM</strong></td>
58    <td> &gt; 64 kB </td>
59    <td> &gt; 180 kB</td>
60  </tr>
61
62  <tr>
63    <td> <strong>Static RAM</strong></td>
64    <td> &gt; 2 kB </td>
65    <td> &gt; 4 kB</td>
66  </tr>
67
68  <tr>
69    <td> <strong>Stack</strong></td>
70    <td> &gt; 2 kB </td>
71    <td> &gt; 8 kB</td>
72  </tr>
73
74  <tr>
75    <td> <strong>Heap</strong></td>
76    <td> &gt; 2 kB </td>
77    <td> &gt; 8 kB</td>
78  </tr>
79
80  <tr>
81    <td> <strong>Display buffer</strong></td>
82    <td> &gt; 1 &times; <em>hor. res.</em> pixels </td>
83    <td> &gt; 10 &times; <em>hor. res.</em> pixels </td>
84  </tr>
85
86  <tr>
87    <td> <strong>Compiler</strong></td>
88    <td colspan="2"> C99 or newer </td>
89  </tr>
90</table>
91
92*Note that the memory usage might vary depending on the architecture, compiler and build options.*
93
94Just to mention some platforms:
95- STM32F1, STM32F3, STM32F4, STM32F7, STM32L4, STM32L5, STM32H7
96- Microchip dsPIC33, PIC24, PIC32MX, PIC32MZ
97- NXP: Kinetis, LPC, iMX, iMX RT
98- [Linux frame buffer](https://blog.lvgl.io/2018-01-03/linux_fb) (/dev/fb)
99- [Raspberry Pi](http://www.vk3erw.com/index.php/16-software/63-raspberry-pi-official-7-touchscreen-and-littlevgl)
100- [Espressif ESP32](https://github.com/lvgl/lv_port_esp32)
101- [Infineon Aurix](https://github.com/lvgl/lv_port_aurix)
102- Nordic NRF52 Bluetooth modules
103- Quectel modems
104
105## Get started
106This list shows the recommended way of learning the library:
1071. Check the [Online demos](https://lvgl.io/demos) to see LVGL in action (3 minutes)
1082. Read the [Introduction](https://docs.lvgl.io/latest/en/html/intro/index.html) page of the documentation (5 minutes)
1093. Get familiar with the basics on the [Quick overview](https://docs.lvgl.io/latest/en/html/get-started/quick-overview.html) page (15 minutes)
1104. Set up a [Simulator](https://docs.lvgl.io/latest/en/html/get-started/pc-simulator.html) (10 minutes)
1115. Try out some [Examples](https://github.com/lvgl/lv_examples/)
1126. Port LVGL to a board. See the [Porting](https://docs.lvgl.io/latest/en/html/porting/index.html) guide or check the ready to use [Projects](https://github.com/lvgl?q=lv_port_&type=&language=)
1137. Read the [Overview](https://docs.lvgl.io/latest/en/html/overview/index.html) page to get a better understanding of the library (2-3 hours)
1148. Check the documentation of the [Widgets](https://docs.lvgl.io/latest/en/html/widgets/index.html) to see their features and usage
1159. If you have questions go to the [Forum](http://forum.lvgl.io/)
11610. Read the [Contributing](https://docs.lvgl.io/latest/en/html/contributing/index.html) guide to see how you can help to improve LVGL (15 minutes)
117
118## Examples
119
120For more examples see the [lv_examples](https://github.com/lvgl/lv_examples) repository.
121
122### Button with label
123```c
124lv_obj_t * btn = lv_btn_create(lv_scr_act(), NULL);     /*Add a button to the current screen*/
125lv_obj_set_pos(btn, 10, 10);                            /*Set its position*/
126lv_obj_set_size(btn, 100, 50);                          /*Set its size*/
127lv_obj_set_event_cb(btn, btn_event_cb);                 /*Assign a callback to the button*/
128
129lv_obj_t * label = lv_label_create(btn, NULL);          /*Add a label to the button*/
130lv_label_set_text(label, "Button");                     /*Set the labels text*/
131
132...
133
134void btn_event_cb(lv_obj_t * btn, lv_event_t event)
135{
136    if(event == LV_EVENT_CLICKED) {
137        printf("Clicked\n");
138    }
139}
140```
141![LVGL button with label example](https://raw.githubusercontent.com/lvgl/docs/latest/misc/simple_button_example.gif)
142
143### LVGL from Micropython
144Learn more about [Micropython](https://docs.lvgl.io/latest/en/html/get-started/micropython.html).
145```python
146# Create a Button and a Label
147scr = lv.obj()
148btn = lv.btn(scr)
149btn.align(lv.scr_act(), lv.ALIGN.CENTER, 0, 0)
150label = lv.label(btn)
151label.set_text("Button")
152
153# Load the screen
154lv.scr_load(scr)
155```
156
157## Contributing
158LVGL 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.
159
160For a detailed description of contribution opportunities visit the [Contributing](https://docs.lvgl.io/latest/en/html/contributing/index.html) section of the documentation.
161