Let's try making some changes to the code in the main.cpp file. First, let's make the text "Hello, ESP32-S3!" larger. To do this, we'll need to create a new style and customize it by changing the font to one that supports the desired text size.

// Create and display label
lv_obj_t *label = lv_label_create(lv_scr_act());
// Create a style for text
static lv_style_t style;
lv_style_init(&style);

// Customize the style by setting the font
// Here lv_font_montserrat_42 is an example font
lv_style_set_text_font(&style, &lv_font_montserrat_42);

// Applying style to label
lv_obj_add_style(label, &style, 0);
    
lv_label_set_text(label, "Hello, ESP32-S3!");
lv_obj_align(label, LV_ALIGN_CENTER, 0, 0);

Let's try adding animation.

To set up animation for LVGL interface elements (for example, for a label), you need to perform several steps:

• Create an animation with a start and end state (for example, changing position, size, or opacity).
• Specify the animation duration and other parameters, such as delay or repeat.
• Start the animation.

Example code for creating a simple animation:

// Function for position animation
static void anim_x_cb(void * var, int32_t v) {
    lv_obj_set_x((lv_obj_t *)var, v);
}

void create_animation(lv_obj_t * label) {
    // Create animation
    lv_anim_t a;
    lv_anim_init(&a);
    
    // Setting animation parameters
    lv_anim_set_var(&a, label);            // Animated object
    lv_anim_set_exec_cb(&a, anim_x_cb);    // Callback for changing a property (e.g. position)
    lv_anim_set_values(&a, 0, 100);        // From initial position x=0 to x=100
    lv_anim_set_time(&a, 1000);            // Animation duration  (1000 ms)
    lv_anim_set_delay(&a, 500);            // Delay before start (500 ms)
    lv_anim_set_repeat_count(&a, LV_ANIM_REPEAT_INFINITE); // Infinite repeat

    // Let's start the animation
    lv_anim_start(&a);
}

This example creates an animation that moves a label along the X axis from 0 to 100 pixels in 1 second, with a 500ms delay and looping infinitely.

Applying an animation to a label:

• Define your animation in a separate function (like the example above).
• Call this function after creating the label.

lv_label_set_text(label, "Hello, ESP32-S3!");
lv_obj_align(label, LV_ALIGN_CENTER, 0, 0);
create_animation(label); 

If we want to move the label along the Y axis, we simply change the line

lv_obj_set_x((lv_obj_t *)var, v); 

as follows

lv_obj_set_y((lv_obj_t *)var, v);

Let's change the program so that it cyclically changes the text in the label field.

To do this, we'll create an array of words.

// Array of words to display
static const char *words[] = {
    "Hello",
    "World",
    "This",
    "Is",
    "LVGL",
    "On",
    "ESP32"
};
static const int num_words = sizeof(words) / sizeof(words[0]);

Let's create the 'update_label_text' function. The 'update_label_text' function is responsible for updating the text displayed on a label widget in the LVGL GUI. This function is called periodically by a timer to cycle through a predefined list of words.

static void update_label_text(lv_timer_t * timer) {
    static int word_index = 0;
    lv_obj_t * label = (lv_obj_t *)timer->user_data;
    
    // Update label text to the next word
    lv_label_set_text(label, words[word_index]);

    // Move to the next word index, wrap around if necessary
    word_index = (word_index + 1) % num_words;
}

Now let's create the 'create_label_with_timer' function. This function creates a label widget on the LVGL screen and sets up a timer to periodically update its text. This provides a dynamic text display that cycles through a list of words.

void create_label_with_timer(lv_obj_t * parent) {
    // Create label
    lv_obj_t * label = lv_label_create(parent);
    
    // Create style for text
    static lv_style_t style;
    lv_style_init(&style);
    
    // Set font style
    lv_style_set_text_font(&style, &lv_font_montserrat_48);
    
    // Apply style to label
    lv_obj_add_style(label, &style, 0);
    
    // Set initial text
    lv_label_set_text(label, words[0]);
    lv_obj_align(label, LV_ALIGN_CENTER, 0, 0);
    
    // Create timer to update text every 1 second
    lv_timer_t * timer = lv_timer_create(update_label_text, 1000, label);
}

Let's replace this section of code in the 'app_main' function

// Create and display label
lv_obj_t *label = lv_label_create(lv_scr_act());
// Create a style for text
static lv_style_t style;
lv_style_init(&style);

// Customize the style by setting the font
// Here lv_font_montserrat_42 is an example font
lv_style_set_text_font(&style, &lv_font_montserrat_42);

// Applying style to label
lv_obj_add_style(label, &style, 0);
    
lv_label_set_text(label, "Hello, ESP32-S3!");
lv_obj_align(label, LV_ALIGN_CENTER, 0, 0);

 with

//lv_obj_t *label = lv_label_create(lv_scr_act());
create_label_with_timer(lv_scr_act());

The result: