Need help with keypad navigation w/ epaper display

[riley-p-mtu]

Hello! I am a student working on an open source e-reader project and I would like to use buttons to navigate through the menu screens. I really want the buttons to turn black when focused and to go to a different screen when pressed. I have gotten the style down, but initializing the buttons does not work for me, it does not change focus on the screen by moving through the group. I am using an ESP32 with arduino IDE.

I have tried printing the states of the buttons and the pointer to the currently focused button. I can see the state change and the focus address change but the screen does not reflect this. Not sure if its a partial refresh issue or the buttons needing extra callbacks. I am using EEZ studio to design the UI. I had originally let EEZ studio take care of initializing the groups, but now I am testing manually making the groups, it still does not refresh properly. Does EEZ studio/lvgl take care of the button presses? Is my screen refreshing a concern when it works with everything else? Please let me know if anyone has it working!

Here's some code:

`
#define SCREEN_HOR 648
#define SCREEN_VER 480
#define BUFFER_SIZE (SCREEN_HOR * SCREEN_VER / 8)

const int BTN_NEXT = 17; // top left rocker (up)
const int BTN_PREV = 12; // bottom left rocker (down)
int32_t page_index;

void setup()
{
Serial.begin(115200);

/* Initialize screen */
pinMode(EPD_CS_PIN, OUTPUT);
pinMode(EPD_DC_PIN, OUTPUT);
pinMode(EPD_RST_PIN, OUTPUT);
pinMode(EPD_BUSY_PIN, INPUT);

/* Initialize buttons*/
pinMode(BTN_NEXT, INPUT);
pinMode(BTN_PREV, INPUT);

digitalWrite(EPD_CS_PIN, 1);
SPI.begin(EPD_SCK_PIN, 12, EPD_MOSI_PIN, EPD_CS_PIN);
EPD_5IN83_V2_Init();
EPD_5IN83_V2_Clear();

/* Initialize buffer & display */
lv_init();
lv_tick_set_cb(get_millis);
Serial.println("LV init");
uint8_t buf = (uint8_t) malloc(BUFFER_SIZE);
lv_display_t *display = lv_display_create(SCREEN_HOR, SCREEN_VER);
lv_display_set_flush_cb(display, screen_flush_cb); // Setting display flush callback
lv_display_set_buffers(display, buf, NULL, BUFFER_SIZE, LV_DISPLAY_RENDER_MODE_PARTIAL);

/* Initialize UI */
ui_init();
Serial.println("UI init");

button_init();
}

void loop()
{
lv_timer_handler(); // LVGL timer
ui_tick(); // EEZ studio timer
sleep(10);
Serial.println("tick");
}

uint32_t get_millis(void)
{
return millis();
}

void sleep(int time)
{
delay(time);
}

void screen_flush_cb(lv_display_t * display, const lv_area_t * area, uint8_t * px_map)
{
Serial.println("Flushing");
if(area->x1 == 0 && area->y1 == 0)
{
EPD_5IN83_V2_SendCommand(0x13); // Tell display we're going to send pixel data
}
// Calculate size of buffer
uint32_t len = (area->x2 - area->x1 + EPD_5IN83_V2_WIDTH * (area->y2 - area->y1)) / 8;
px_map += 8; // Adjusts pixel buffer (first 8 bytes are metadata or smth)
EPD_5IN83_V2_SendData_Invert(px_map, len); // transfer pixel data
Serial.println("Flushed!");
if(lv_display_flush_is_last(display))
{
EPD_5IN83_V2_TurnOnDisplay();
}
lv_display_flush_ready(display); // Tell LVGL the buffer can be flushed and reused
}

void button_init()
{
lv_group_t * g = lv_group_create();

lv_obj_t *button1 = lv_obj_get_child(objects.main, 0);
lv_obj_t *button2 = lv_obj_get_child(objects.main, 1);
lv_group_add_obj(g, button1);
lv_group_add_obj(g, button2);
lv_group_focus_obj(button1);

lv_indev_t * indev = lv_indev_create();
lv_indev_set_type(indev, LV_INDEV_TYPE_KEYPAD);
lv_indev_set_read_cb(indev, keyboard_read);
lv_indev_set_group(indev, g);
}

void keyboard_read(lv_indev_t * indev, lv_indev_data_t * data) {
if(digitalRead(BTN_NEXT) == HIGH)
{
data->key = LV_KEY_NEXT; /* Get the last pressed or released key */
data->state = LV_INDEV_STATE_PRESSED;
}
else if (digitalRead(BTN_PREV) == HIGH)
{
data->key = LV_KEY_PREV;
data->state = LV_INDEV_STATE_PRESSED;
}
else
{
data->state = LV_INDEV_STATE_RELEASED;
}
}
`
Thank you for reading this post :)