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@ -50,7 +50,7 @@ LVGL provides everything you need to create embedded GUI with easy-to-use graphi
* **Documentation** and API references * **Documentation** and API references
## Supported devices ## Supported devices
Basically, every modern controller (which is able to drive a display( is suitable to run LVGL. The minimal requirements are: Basically, every modern controller (which is able to drive a display) is suitable to run LVGL. The minimal requirements are:
- 16, 32 or 64 bit microcontroller or processor - 16, 32 or 64 bit microcontroller or processor
- > 16 MHz clock speed is recommended - > 16 MHz clock speed is recommended
- Flash/ROM: > 64 kB for the very essential components (> 180 kB is recommended) - Flash/ROM: > 64 kB for the very essential components (> 180 kB is recommended)
@ -90,11 +90,11 @@ Choose a project with your favourite IDE:
The steps below show how to setup LVGL on an embedded system with a display and a touchpad. The steps below show how to setup LVGL on an embedded system with a display and a touchpad.
You can use the [Simulators](https://docs.lvgl.io/v7/en/html/get-started/pc-simulator) to get ready to use projects which can be run on your PC. You can use the [Simulators](https://docs.lvgl.io/v7/en/html/get-started/pc-simulator) to get ready to use projects which can be run on your PC.
1. [Download](https://lvgl.com/developers) or [Clone](https://github.com/lvgl/lvgl) the library 1. [Download](https://github.com/lvgl/lvgl/archive/master.zip) or [Clone](https://github.com/lvgl/lvgl) the library
2. Copy the `lvgl` folder into your project 2. Copy the `lvgl` folder into your project
3. Copy `lvgl/lv_conf_template.h` as `lv_conf.h` next to the `lvgl` folder and set at least `LV_HOR_RES_MAX`, `LV_VER_RES_MAX` and `LV_COLOR_DEPTH`. Don't forget to **change the `#if 0` statement near the top of the file to `#if 1`**, otherwise you will get compilation errors. 3. Copy `lvgl/lv_conf_template.h` as `lv_conf.h` next to the `lvgl` folder, change the `#if 0` statement near the top of the file to `#if 1` and set at least `LV_HOR_RES_MAX`, `LV_VER_RES_MAX` and `LV_COLOR_DEPTH`.
4. Include `lvgl/lvgl.h` where you need to use LVGL related functions. 4. Include `lvgl/lvgl.h` where you need to use LVGL related functions.
5. Call `lv_tick_inc(x)` every `x` milliseconds **in a Timer or Task** (`x` should be between 1 and 10). It is required for the internal timing of LVGL. 5. Call `lv_tick_inc(x)` every `x` milliseconds (should be 1..10) in a Timer or Task. It is required for the internal timing of LVGL.
6. Call `lv_init()` 6. Call `lv_init()`
7. Create a display buffer for LVGL 7. Create a display buffer for LVGL
```c ```c
@ -102,7 +102,7 @@ static lv_disp_buf_t disp_buf;
static lv_color_t buf[LV_HOR_RES_MAX * 10]; /*Declare a buffer for 10 lines*/ static lv_color_t buf[LV_HOR_RES_MAX * 10]; /*Declare a buffer for 10 lines*/
lv_disp_buf_init(&disp_buf, buf, NULL, LV_HOR_RES_MAX * 10); /*Initialize the display buffer*/ lv_disp_buf_init(&disp_buf, buf, NULL, LV_HOR_RES_MAX * 10); /*Initialize the display buffer*/
``` ```
8. Implement and register a function which can **copy a pixel array** to an area of your display: 8. Implement and register a function which can copy a pixel array to an area of your display:
```c ```c
lv_disp_drv_t disp_drv; /*Descriptor of a display driver*/ lv_disp_drv_t disp_drv; /*Descriptor of a display driver*/
lv_disp_drv_init(&disp_drv); /*Basic initialization*/ lv_disp_drv_init(&disp_drv); /*Basic initialization*/
@ -115,7 +115,7 @@ void my_disp_flush(lv_disp_t * disp, const lv_area_t * area, lv_color_t * color_
int32_t x, y; int32_t x, y;
for(y = area->y1; y <= area->y2; y++) { for(y = area->y1; y <= area->y2; y++) {
for(x = area->x1; x <= area->x2; x++) { for(x = area->x1; x <= area->x2; x++) {
set_pixel(x, y, *color_p); /* Put a pixel to the display.*/ my_set_pixel(x, y, *color_p); /* Put a pixel to the display.*/
color_p++; color_p++;
} }
} }
@ -124,7 +124,7 @@ void my_disp_flush(lv_disp_t * disp, const lv_area_t * area, lv_color_t * color_
} }
``` ```
9. Implement and register a function which can **read an input device**. E.g. for a touch pad: 9. Implement and register a function which can read an input device. E.g. for a touch pad:
```c ```c
lv_indev_drv_init(&indev_drv); /*Descriptor of a input device driver*/ lv_indev_drv_init(&indev_drv); /*Descriptor of a input device driver*/
indev_drv.type = LV_INDEV_TYPE_POINTER; /*Touch pad is a pointer-like device*/ indev_drv.type = LV_INDEV_TYPE_POINTER; /*Touch pad is a pointer-like device*/
@ -133,16 +133,8 @@ lv_indev_drv_register(&indev_drv); /*Finally register the driver*/
bool my_touchpad_read(lv_indev_drv_t * indev_driver, lv_indev_data_t * data) bool my_touchpad_read(lv_indev_drv_t * indev_driver, lv_indev_data_t * data)
{ {
static lv_coord_t last_x = 0; data->state = my_touchpad_is_pressed() ? LV_INDEV_STATE_PR : LV_INDEV_STATE_REL;
static lv_coord_t last_y = 0; if(data->state == LV_INDEV_STATE_PR) touchpad_get_xy(&data->point.x, &data->point.y);
/*Save the state and save the pressed coordinate*/
data->state = touchpad_is_pressed() ? LV_INDEV_STATE_PR : LV_INDEV_STATE_REL;
if(data->state == LV_INDEV_STATE_PR) touchpad_get_xy(&last_x, &last_y);
/*Set the coordinates (if released use the last pressed coordinates)*/
data->point.x = last_x;
data->point.y = last_y;
return false; /*Return `false` because we are not buffering and no more data to read*/ return false; /*Return `false` because we are not buffering and no more data to read*/
} }
@ -153,17 +145,17 @@ It will redraw the screen if required, handle input devices etc.
## Learn the basics ## Learn the basics
In this section you can ready the very basics. For a more detailed guide check the [Quick overview](https://docs.lvgl.io/v7/en/html/get-started/quick-overview.html#learn-the-basics) in the documentation. In this section you can read the very basics of LVGL. For a more detailed guide check the [Quick overview](https://docs.lvgl.io/v7/en/html/get-started/quick-overview.html#learn-the-basics) in the documentation.
### Widgets (Objects) ### Widgets (Objects)
The graphical elements like Buttons, Labels, Sliders, Charts etc are called objects in LittelvGL. Go to [Object types](https://docs.lvgl.io/v7/en/html/widgets/index) to see the full list of available types. The graphical elements like Buttons, Labels, Sliders, Charts etc are called objects or widgets in LVGL. Go to [Widgets](https://docs.lvgl.io/v7/en/html/widgets/index) to see the full list of available types.
Every object has a parent object. The child object moves with the parent and if you delete the parent the children will be deleted too. Children can be visible only on their parent. Every object has a parent object. The child object moves with the parent and if you delete the parent the children will be deleted too. Children can be visible only on their parent.
The *screen* are the "root" parents. To get the current screen call `lv_scr_act()`. The *screen* are the "root" parents. To get the current screen call `lv_scr_act()`.
You can create a new object with `lv_<type>_create(parent, obj_to_copy)`. It will return an `lv_obj_t *` variable which should be used as a reference to the object to set its parameters. You can create a new object with `lv_<type>_create(parent, obj_to_copy)`. It will return an `lv_obj_t *` variable which should be used as a reference to the object to set its parameters later.
The first parameter is the desired *parent*, the second parameters can be an object to copy (`NULL` if unused). The first parameter is the desired *parent*, the second parameters can be an object to copy (`NULL` if unused).
For example: For example:
```c ```c
@ -177,15 +169,22 @@ lv_obj_set_y(btn1, 10);
lv_obj_set_size(btn1, 200, 50); lv_obj_set_size(btn1, 200, 50);
``` ```
The objects has type specific parameters too which can be set by `lv_<type>_set_<paramters_name>(obj, <value>)` functions. For example: The objects have type specific parameters too which can be set by `lv_<type>_set_<paramters_name>(obj, <value>)` functions. For example:
```c ```c
lv_slider_set_value(slider1, 70, LV_ANIM_ON); lv_slider_set_value(slider1, 70, LV_ANIM_ON);
``` ```
To see the full API visit the documentation of the object types or the related header file (e.g. `lvgl/src/lv_objx/lv_slider.h`). To see the full API visit the documentation of the object types or the related header file (e.g. `lvgl/src/lv_objx/lv_slider.h`).
To create a new screen pass `NULL` as the fisrt paramater of a *create* function:
```c
lv_obj_t * scr2 = lv_obj_create(NULL, NULL); /*Create a screen*/
lv_scr_load(scr2); /*Load the new screen*/
```
### Styles ### Styles
Widgets are created with a default appearance but it can be changed by adding new styles to the object. A new style can be created like this: Widgets are created with a default appearance but it can be changed by adding new styles to them. A new style can be created like this:
```c ```c
static lv_style_t style1; /*Should be static, global or dynamically allocated*/ static lv_style_t style1; /*Should be static, global or dynamically allocated*/
lv_style_init(&style1); lv_style_init(&style1);
@ -193,15 +192,15 @@ lv_style_set_bg_color(&style1, LV_STATE_DEFAULT, LV_COLOR_RED); /*Default backg
lv_style_set_bg_color(&style1, LV_STATE_PRESSED, LV_COLOR_BLUE); /*Pressed background color*/ lv_style_set_bg_color(&style1, LV_STATE_PRESSED, LV_COLOR_BLUE); /*Pressed background color*/
``` ```
The wigedt have *parts* which can be referenced via `LV_<TYPE>_PART_<PART_NAME>`. E.g. `LV_BRN_PART_MAIN` or `LV_SLIDER_PART_KNOB`. See the documentation of the widgets to see the exisitng parts. The wigedt have *parts* which can be referenced via `LV_<TYPE>_PART_<PART_NAME>`. E.g. `LV_BTN_PART_MAIN` or `LV_SLIDER_PART_KNOB`. See the documentation of the widgets to see the exisitng parts.
To add the style to a button: To add the style to a button:
``` ```c
lv_obj_add_style(btn1, LV_BTN_PART_MAIN, &style1); lv_obj_add_style(btn1, LV_BTN_PART_MAIN, &style1);
``` ```
To remove all styles from an object use: To remove all styles from a part of an object:
```c ```cc
lv_obj_reset_style_list(obj, LV_OBJ_PART_MAIN); lv_obj_reset_style_list(obj, LV_OBJ_PART_MAIN);
``` ```
@ -282,6 +281,7 @@ LVGL has a monthly periodic release cycle.
  - Make a patch release from `master`.   - Make a patch release from `master`.
  - After that merge the new features from the `dev` to `master` branch.   - After that merge the new features from the `dev` to `master` branch.
  - In the rest of the month merge only patches into `master` and new features into `dev` branch.   - In the rest of the month merge only patches into `master` and new features into `dev` branch.
## Contributing ## Contributing
To ask questions please use the [Forum](https://forum.lvgl.io). To ask questions please use the [Forum](https://forum.lvgl.io).
For development-related things (bug reports, feature suggestions) use [GitHub's Issue tracker](https://github.com/lvgl/lvgl/issues). For development-related things (bug reports, feature suggestions) use [GitHub's Issue tracker](https://github.com/lvgl/lvgl/issues).