How to run LVGL on M5Stack

  • Sorry I did not understand that I still need to confirm the download below sorry all good now

  • I fetched some of these examples for Core2 and adapted them to build with PlatformIO:

    work through all branches!

  • these examples use the obsolete lv_arduino library which is based upon lvgl version 7

    Anybody had success getting a Core2 to work with lvgl version 8?

    I see there were some massive changes between lvgl 7 and 8


  • I have a working demo of LVGL 8.1 running on my M5Core2.
    To succeed one have to carefully read the 8.0.0 changes in the changelog:

    Especially this: "lv_disp_drv_t, lv_indev_drv_t, lv_fs_drv_t needs to be static"
    So you have to move these structures outside the setup function as static.

    static lv_disp_drv_t disp_drv;
    static lv_indev_drv_t indev_drv;

    Good luck!

  • Hello,

    Same here, I have started from scratch with LVGL 8.1 / VSCode / PIO
    Still learning a lot but so far so good :)

  • I'm interesting of basic example (display at least a label), I'm learning C, and discover lvgl which seems amazing.
    I can compile without errors but when I push my code inside my core2, nothing happened 🤔

  • @got would you share some code sample so that we can have a look?
    I am not an expert at all but i can try helping you.

  • That's what I used, but nothing's displayed.
    I think there is something which is missing in lv_conf.h in order to be able to linked it to the M5 LCD display.
    What I'm trying to do is to backport the UI Flow Drawing Board to C, just for fun, and also to learn more about how it works ^^

    #include <M5Core2.h>
    #include <Arduino.h>
    #include <lvgl.h>
    #include "DrawingBoard.h"
    #include "KeyMapping.h"
    int size = 5;
    int color = 0;
    lv_obj_t * drawing_label(char* title, int32_t x, int32_t y) {
      lv_obj_t * label = lv_label_create(lv_scr_act());
      lv_label_set_recolor(label, true);
      lv_label_set_text(label, title);
      lv_obj_set_x(label, x);
      lv_obj_set_y(label, y);
      return label;
    char* write_size(int32_t size) {
      char buf[8];
      sprintf(buf, "Size: %d", size);
      return buf;
    lv_obj_t* label0 = drawing_label("Color", 50, 220);
    lv_obj_t* label1 = drawing_label(write_size(size), 145, 220);
    lv_obj_t* label2 = drawing_label("Clear", 235, 220);
    int32_t get_color() {
      switch (color) {
      case 1:
        return TFT_GREEN;
      case 2:
        return TFT_BLUE;
      case 3:
        return TFT_RED;
      case 4:
        return TFT_YELLOW;
      case 5:
        return TFT_PINK;
      case 6:
        return TFT_CYAN;
      case 7:
        return TFT_ORANGE;
        return TFT_WHITE;
    void draw_point(int32_t x, int32_t y) {
      M5.Lcd.drawCircle(x, y, size, get_color());
      M5.Lcd.fillCircle(x, y, size, get_color());
    void change_color() {
      color = color + 1;
      if (color >= 8) {
        color = 0;
      lv_obj_set_style_text_color(label0, lv_color_hex(get_color()), LV_STATE_ANY);
    void change_size() {
      size = size + 5;
      if (size == 20) {
        size = 5;
      lv_label_set_text(label0, write_size(size));
    boolean is_screen_limit_reached(int32_t y) {
      return y >= 220 - size;
    void draw_points() {
      if (M5.Touch.ispressed()) {
        TouchPoint_t coordinate = M5.Touch.getPressPoint();
        if (is_screen_limit_reached(coordinate.y)) {
          draw_point(coordinate.x, coordinate.y);
    void clear_board() {
      color = 0;
      size = 5;
    void DrawingBoard::loop() {
      if (KEY_LEFT.isPressed()) {
      } else if (KEY_RIGHT.isPressed()) {
      } else if (KEY_CENTER.isPressed()) {
      } else {

  • I'll try to create a GitHub repository tonight in order to reproduce it easily, and help people if we can make it works :p

  • I did not take the same approach because I am not using the M5.Lcd class but TFT_eSPI
    What I understand is that M5.Lcd is also based on TFT_eSPI but M5Stack did their own implementation.
    As I want full portability on my other displays and ESP boards I decided not to use M5.Lcd.
    However it should work in your case.
    From what I see you are missing several initialization steps and I guess this is the reason why it is not working

    Here is a sample you can use:

    #include "M5Core2.h"
    #include "lvgl.h"
    #include "MyLVEventHandler.h"

    #define DISP_HOR_RES 320
    #define DISP_VER_RES 240


    static lv_disp_draw_buf_t draw_buf;

    void tft_lv_initialization()

    static lv_color_t buf1[(DISP_HOR_RES * DISP_VER_RES) / 10]; /*Declare a buffer for 1/10 screen size*/
    static lv_color_t buf2[(DISP_HOR_RES * DISP_VER_RES) / 10]; // second buffer is optionnal
    lv_disp_draw_buf_init(&draw_buf, buf1, buf2, (DISP_HOR_RES * DISP_VER_RES) / 10); // Initialize `disp_buf` display buffer with the buffer(s). With only one buffer use NULL instead buf_2
    tft.begin();        // TFT init
    tft.setRotation(1); // 1=horizontal 3=upside down 0=left 2=right


    // Display flushing
    void my_disp_flush(lv_disp_drv_t *disp, const lv_area_t *area, lv_color_t *color_p)
    uint32_t w = (area->x2 - area->x1 + 1);
    uint32_t h = (area->y2 - area->y1 + 1);

    tft.setAddrWindow(area->x1, area->y1, w, h);
    tft.pushColors(&color_p->full, w * h, true);


    void init_disp_driver()

    // Initialize the display
    static lv_disp_drv_t disp_drv;     /*Descriptor of a display driver / //disp_drv.full_refresh = true;  direct mode can also be set true*/
    lv_disp_drv_init(&disp_drv);       /*Basic initialization*/
    disp_drv.flush_cb = my_disp_flush; /*Set your driver function*/
    disp_drv.draw_buf = &draw_buf;     /*Assign the buffer to the display*/
    disp_drv.hor_res = DISP_HOR_RES;   /*Set the horizontal resolution of the display*/
    disp_drv.ver_res = DISP_VER_RES;   /*Set the vertical resolution of the display*/
    lv_disp_drv_register(&disp_drv);   /*Finally register the driver*/


  • It seems you're not using the latest version of lvgl (the 8)

    I'm trying to make it work here:

  • lol I'm from Toulouse :)

    Yes I am using version 8, what makes you think otherwise?
    I'll have a look at your GitHub files ;)

  • @got said in How to run LVGL on M5Stack:


    btw as you've already guessed, you have to tweak the lvgl_conf.h file otherwise it won't probably work out of the box

  • @erich haha that's funny how the world is really small ^^

    About the version 8, my bad, I was thinking about something else, I add an error with:
    tft.pushColors(&color_p->full, w * h, true);
    I had to change it to:
    tft.pushColors((uint16_t*) &color_p->full, w * h, true);

    here's my lv_conf.h

     * @file lv_conf.h
     * Configuration file for v8.0.2
     * COPY THIS FILE AS `lv_conf.h` NEXT TO the `lvgl` FOLDER
    #if 1 /*Set it to "1" to enable content*/
    #ifndef LV_CONF_H
    #define LV_CONF_H
    /*clang-format off*/
    #include <stdint.h>
    #define LV_HOR_RES_MAX 320
    #define LV_VER_RES_MAX 240
    /*Color depth: 1 (1 byte per pixel), 8 (RGB332), 16 (RGB565), 32 (ARGB8888)*/
    #define LV_COLOR_DEPTH     32
    /*Swap the 2 bytes of RGB565 color. Useful if the display has a 8 bit interface (e.g. SPI)*/
    #define LV_COLOR_16_SWAP   0
    /*Enable more complex drawing routines to manage screens transparency.
     *Can be used if the UI is above another layer, e.g. an OSD menu or video player.
     *Requires `LV_COLOR_DEPTH = 32` colors and the screen's `bg_opa` should be set to non LV_OPA_COVER value*/
    #define LV_COLOR_SCREEN_TRANSP    0
    /*Images pixels with this color will not be drawn if they are  chroma keyed)*/
    #define LV_COLOR_CHROMA_KEY    lv_color_hex(0x00ff00)         /*pure green*/
    /*1: use custom malloc/free, 0: use the built-in `lv_mem_alloc()` and `lv_mem_free()`*/
    #define LV_MEM_CUSTOM      0
    #if LV_MEM_CUSTOM == 0
    /*Size of the memory available for `lv_mem_alloc()` in bytes (>= 2kB)*/
    #  define LV_MEM_SIZE    (32U * 1024U)          /*[bytes]*/
    /*Set an address for the memory pool instead of allocating it as a normal array. Can be in external SRAM too.*/
    #  define LV_MEM_ADR          0     /*0: unused*/
    #else       /*LV_MEM_CUSTOM*/
    #  define LV_MEM_CUSTOM_INCLUDE <stdlib.h>   /*Header for the dynamic memory function*/
    #  define LV_MEM_CUSTOM_ALLOC     malloc
    #  define LV_MEM_CUSTOM_FREE      free
    #  define LV_MEM_CUSTOM_REALLOC   realloc
    #endif     /*LV_MEM_CUSTOM*/
    /*Use the standard `memcpy` and `memset` instead of LVGL's own functions. (Might or might not be faster).*/
    #define LV_MEMCPY_MEMSET_STD    0
    /*Default display refresh period. LVG will redraw changed ares with this period time*/
    #define LV_DISP_DEF_REFR_PERIOD     30      /*[ms]*/
    /*Input device read period in milliseconds*/
    #define LV_INDEV_DEF_READ_PERIOD    30      /*[ms]*/
    /*Use a custom tick source that tells the elapsed time in milliseconds.
     *It removes the need to manually update the tick with `lv_tick_inc()`)*/
    #define LV_TICK_CUSTOM     0
    #define LV_TICK_CUSTOM_INCLUDE  "Arduino.h"         /*Header for the system time function*/
    #define LV_TICK_CUSTOM_SYS_TIME_EXPR (millis())     /*Expression evaluating to current system time in ms*/
    #endif   /*LV_TICK_CUSTOM*/
    /*Default Dot Per Inch. Used to initialize default sizes such as widgets sized, style paddings.
     *(Not so important, you can adjust it to modify default sizes and spaces)*/
    #define LV_DPI_DEF                  130     /*[px/inch]*/
     * Drawing
    /*Enable complex draw engine.
     *Required to draw shadow, gradient, rounded corners, circles, arc, skew lines, image transformations or any masks*/
    #define LV_DRAW_COMPLEX 1
    #if LV_DRAW_COMPLEX != 0
    /*Allow buffering some shadow calculation.
     *LV_SHADOW_CACHE_SIZE is the max. shadow size to buffer, where shadow size is `shadow_width + radius`
     *Caching has LV_SHADOW_CACHE_SIZE^2 RAM cost*/
    #define LV_SHADOW_CACHE_SIZE    0
    #endif /*LV_DRAW_COMPLEX*/
    /*Default image cache size. Image caching keeps the images opened.
     *If only the built-in image formats are used there is no real advantage of caching. (I.e. if no new image decoder is added)
     *With complex image decoders (e.g. PNG or JPG) caching can save the continuous open/decode of images.
     *However the opened images might consume additional RAM.
     *0: to disable caching*/
    #define LV_IMG_CACHE_DEF_SIZE       0
    /*Maximum buffer size to allocate for rotation. Only used if software rotation is enabled in the display driver.*/
    #define LV_DISP_ROT_MAX_BUF         (10*1024)
     * GPU
    /*Use STM32's DMA2D (aka Chrom Art) GPU*/
    #define LV_USE_GPU_STM32_DMA2D  0
    #if LV_USE_GPU_STM32_DMA2D
    /*Must be defined to include path of CMSIS header of target processor
    e.g. "stm32f769xx.h" or "stm32f429xx.h"*/
    /*Use NXP's PXP GPU iMX RTxxx platforms*/
    #define LV_USE_GPU_NXP_PXP      0
    /*1: Add default bare metal and FreeRTOS interrupt handling routines for PXP (lv_gpu_nxp_pxp_osa.c)
     *   and call lv_gpu_nxp_pxp_init() automatically during lv_init(). Note that symbol SDK_OS_FREE_RTOS
     *   has to be defined in order to use FreeRTOS OSA, otherwise bare-metal implementation is selected.
     *0: lv_gpu_nxp_pxp_init() has to be called manually before lv_init()
    /*Use NXP's VG-Lite GPU iMX RTxxx platforms*/
    #define LV_USE_GPU_NXP_VG_LITE   0
     * Logging
    /*Enable the log module*/
    #define LV_USE_LOG      1
    #if LV_USE_LOG
    /*How important log should be added:
     *LV_LOG_LEVEL_TRACE       A lot of logs to give detailed information
     *LV_LOG_LEVEL_INFO        Log important events
     *LV_LOG_LEVEL_WARN        Log if something unwanted happened but didn't cause a problem
     *LV_LOG_LEVEL_ERROR       Only critical issue, when the system may fail
     *LV_LOG_LEVEL_USER        Only logs added by the user
     *LV_LOG_LEVEL_NONE        Do not log anything*/
    /*1: Print the log with 'printf';
     *0: User need to register a callback with `lv_log_register_print_cb()`*/
    #  define LV_LOG_PRINTF   0
    /*Enable/disable LV_LOG_TRACE in modules that produces a huge number of logs*/
    #  define LV_LOG_TRACE_MEM            1
    #  define LV_LOG_TRACE_TIMER          1
    #  define LV_LOG_TRACE_INDEV          1
    #  define LV_LOG_TRACE_DISP_REFR      1
    #  define LV_LOG_TRACE_EVENT          1
    #  define LV_LOG_TRACE_OBJ_CREATE     1
    #  define LV_LOG_TRACE_LAYOUT         1
    #  define LV_LOG_TRACE_ANIM           1
    #endif  /*LV_USE_LOG*/
     * Asserts
    /*Enable asserts if an operation is failed or an invalid data is found.
     *If LV_USE_LOG is enabled an error message will be printed on failure*/
    #define LV_USE_ASSERT_NULL          1   /*Check if the parameter is NULL. (Very fast, recommended)*/
    #define LV_USE_ASSERT_MALLOC        1   /*Checks is the memory is successfully allocated or no. (Very fast, recommended)*/
    #define LV_USE_ASSERT_STYLE         0   /*Check if the styles are properly initialized. (Very fast, recommended)*/
    #define LV_USE_ASSERT_MEM_INTEGRITY 0   /*Check the integrity of `lv_mem` after critical operations. (Slow)*/
    #define LV_USE_ASSERT_OBJ           0   /*Check the object's type and existence (e.g. not deleted). (Slow)*/
    /*Add a custom handler when assert happens e.g. to restart the MCU*/
    #define LV_ASSERT_HANDLER_INCLUDE   <stdint.h>
    #define LV_ASSERT_HANDLER   while(1);   /*Halt by default*/
     * Others
    /*1: Show CPU usage and FPS count in the right bottom corner*/
    #define LV_USE_PERF_MONITOR     0
    /*1: Show the used memory and the memory fragmentation  in the left bottom corner
     * Requires LV_MEM_CUSTOM = 0*/
    #define LV_USE_MEM_MONITOR      0
    /*1: Draw random colored rectangles over the redrawn areas*/
    #define LV_USE_REFR_DEBUG       0
    /*Change the built in (v)snprintf functions*/
    #define LV_SPRINTF_CUSTOM   0
    #  define LV_SPRINTF_INCLUDE <stdio.h>
    #  define lv_snprintf     snprintf
    #  define lv_vsnprintf    vsnprintf
    #else   /*LV_SPRINTF_CUSTOM*/
    #  define LV_SPRINTF_USE_FLOAT 0
    #endif  /*LV_SPRINTF_CUSTOM*/
    #define LV_USE_USER_DATA      1
    /*Garbage Collector settings
     *Used if lvgl is binded to higher level language and the memory is managed by that language*/
    #define LV_ENABLE_GC 0
    #if LV_ENABLE_GC != 0
    #  define LV_GC_INCLUDE "gc.h"                           /*Include Garbage Collector related things*/
    #endif /*LV_ENABLE_GC*/
    /*For big endian systems set to 1*/
    #define LV_BIG_ENDIAN_SYSTEM    0
    /*Define a custom attribute to `lv_tick_inc` function*/
    /*Define a custom attribute to `lv_timer_handler` function*/
    /*Define a custom attribute to `lv_disp_flush_ready` function*/
    /*Required alignment size for buffers*/
    /*Will be added where memories needs to be aligned (with -Os data might not be aligned to boundary by default).
     * E.g. __attribute__((aligned(4)))*/
    /*Attribute to mark large constant arrays for example font's bitmaps*/
    /*Complier prefix for a big array declaration in RAM*/
    /*Place performance critical functions into a faster memory (e.g RAM)*/
    /*Prefix variables that are used in GPU accelerated operations, often these need to be placed in RAM sections that are DMA accessible*/
    #define LV_ATTRIBUTE_DMA
    /*Export integer constant to binding. This macro is used with constants in the form of LV_<CONST> that
     *should also appear on LVGL binding API such as Micropython.*/
    #define LV_EXPORT_CONST_INT(int_value) struct _silence_gcc_warning /*The default value just prevents GCC warning*/
    /*Extend the default -32k..32k coordinate range to -4M..4M by using int32_t for coordinates instead of int16_t*/
    #define LV_USE_LARGE_COORD  0
     *   FONT USAGE
    /*Montserrat fonts with ASCII range and some symbols using bpp = 4
    #define LV_FONT_MONTSERRAT_8     0
    #define LV_FONT_MONTSERRAT_10    0
    #define LV_FONT_MONTSERRAT_12    0
    #define LV_FONT_MONTSERRAT_14    1
    #define LV_FONT_MONTSERRAT_16    0
    #define LV_FONT_MONTSERRAT_18    0
    #define LV_FONT_MONTSERRAT_20    0
    #define LV_FONT_MONTSERRAT_22    0
    #define LV_FONT_MONTSERRAT_24    0
    #define LV_FONT_MONTSERRAT_26    0
    #define LV_FONT_MONTSERRAT_28    0
    #define LV_FONT_MONTSERRAT_30    0
    #define LV_FONT_MONTSERRAT_32    0
    #define LV_FONT_MONTSERRAT_34    0
    #define LV_FONT_MONTSERRAT_36    0
    #define LV_FONT_MONTSERRAT_38    0
    #define LV_FONT_MONTSERRAT_40    0
    #define LV_FONT_MONTSERRAT_42    0
    #define LV_FONT_MONTSERRAT_44    0
    #define LV_FONT_MONTSERRAT_46    0
    #define LV_FONT_MONTSERRAT_48    0
    /*Demonstrate special features*/
    #define LV_FONT_MONTSERRAT_12_SUBPX      0
    #define LV_FONT_MONTSERRAT_28_COMPRESSED 0  /*bpp = 3*/
    #define LV_FONT_DEJAVU_16_PERSIAN_HEBREW 0  /*Hebrew, Arabic, Perisan letters and all their forms*/
    #define LV_FONT_SIMSUN_16_CJK            0  /*1000 most common CJK radicals*/
    /*Pixel perfect monospace fonts*/
    #define LV_FONT_UNSCII_8        0
    #define LV_FONT_UNSCII_16       0
    /*Optionally declare custom fonts here.
     *You can use these fonts as default font too and they will be available globally.
     *E.g. #define LV_FONT_CUSTOM_DECLARE   LV_FONT_DECLARE(my_font_1) LV_FONT_DECLARE(my_font_2)*/
    /*Always set a default font*/
    #define LV_FONT_DEFAULT &lv_font_montserrat_14
    /*Enable handling large font and/or fonts with a lot of characters.
     *The limit depends on the font size, font face and bpp.
     *Compiler error will be triggered if a font needs it.*/
    #define LV_FONT_FMT_TXT_LARGE   0
    /*Enables/disables support for compressed fonts.*/
    /*Enable subpixel rendering*/
    #define LV_USE_FONT_SUBPX       0
    /*Set the pixel order of the display. Physical order of RGB channels. Doesn't matter with "normal" fonts.*/
    #define LV_FONT_SUBPX_BGR       0  /*0: RGB; 1:BGR order*/
     * Select a character encoding for strings.
     * Your IDE or editor should have the same character encoding
     * - LV_TXT_ENC_UTF8
    #define LV_TXT_ENC LV_TXT_ENC_UTF8
     /*Can break (wrap) texts on these chars*/
    #define LV_TXT_BREAK_CHARS                  " ,.;:-_"
    /*If a word is at least this long, will break wherever "prettiest"
     *To disable, set to a value <= 0*/
    #define LV_TXT_LINE_BREAK_LONG_LEN          0
    /*Minimum number of characters in a long word to put on a line before a break.
     *Depends on LV_TXT_LINE_BREAK_LONG_LEN.*/
    /*Minimum number of characters in a long word to put on a line after a break.
     *Depends on LV_TXT_LINE_BREAK_LONG_LEN.*/
    /*The control character to use for signalling text recoloring.*/
    #define LV_TXT_COLOR_CMD "#"
    /*Support bidirectional texts. Allows mixing Left-to-Right and Right-to-Left texts.
     *The direction will be processed according to the Unicode Bidirectioanl Algorithm:
    #define LV_USE_BIDI         0
    #if LV_USE_BIDI
    /*Set the default direction. Supported values:
     *`LV_BASE_DIR_LTR` Left-to-Right
     *`LV_BASE_DIR_RTL` Right-to-Left
     *`LV_BASE_DIR_AUTO` detect texts base direction*/
    /*Enable Arabic/Persian processing
     *In these languages characters should be replaced with an other form based on their position in the text*/
    /*Documentation of the widgets:*/
    #define LV_USE_ARC          1
    #define LV_USE_ANIMIMG	    1
    #define LV_USE_BAR          1
    #define LV_USE_BTN          1
    #define LV_USE_BTNMATRIX    1
    #define LV_USE_CANVAS       1
    #define LV_USE_CHECKBOX     1
    #define LV_USE_DROPDOWN     1   /*Requires: lv_label*/
    #define LV_USE_IMG          1   /*Requires: lv_label*/
    #define LV_USE_LABEL        1
    #if LV_USE_LABEL
    #  define LV_LABEL_TEXT_SELECTION         1   /*Enable selecting text of the label*/
    #  define LV_LABEL_LONG_TXT_HINT    1   /*Store some extra info in labels to speed up drawing of very long texts*/
    #define LV_USE_LINE         1
    #define LV_USE_ROLLER       1   /*Requires: lv_label*/
    #  define LV_ROLLER_INF_PAGES       7   /*Number of extra "pages" when the roller is infinite*/
    #define LV_USE_SLIDER       1   /*Requires: lv_bar*/
    #define LV_USE_SWITCH    1
    #define LV_USE_TEXTAREA   1     /*Requires: lv_label*/
    #if LV_USE_TEXTAREA != 0
    #  define LV_TEXTAREA_DEF_PWD_SHOW_TIME     1500    /*ms*/
    #define LV_USE_TABLE  1
     * Widgets
    #define LV_USE_CALENDAR     1
    #  define LV_CALENDAR_DEFAULT_DAY_NAMES {"Mo", "Tu", "We", "Th", "Fr", "Sa", "Su"}
    # else
    #  define LV_CALENDAR_DEFAULT_DAY_NAMES {"Su", "Mo", "Tu", "We", "Th", "Fr", "Sa"}
    # endif
    # define LV_CALENDAR_DEFAULT_MONTH_NAMES {"January", "February", "March",  "April", "May",  "June", "July", "August", "September", "October", "November", "December"}
    # define LV_USE_CALENDAR_HEADER_ARROW       1
    #endif  /*LV_USE_CALENDAR*/
    #define LV_USE_CHART        1
    #define LV_USE_COLORWHEEL   1
    #define LV_USE_IMGBTN       1
    #define LV_USE_KEYBOARD     1
    #define LV_USE_LED          1
    #define LV_USE_LIST         1
    #define LV_USE_METER        1
    #define LV_USE_MSGBOX       1
    #define LV_USE_SPINBOX      1
    #define LV_USE_SPINNER      1
    #define LV_USE_TABVIEW      1
    #define LV_USE_TILEVIEW     1
    #define LV_USE_WIN          1
    #define LV_USE_SPAN         1
    #if LV_USE_SPAN
    /*A line text can contain maximum num of span descriptor */
    #  define LV_SPAN_SNIPPET_STACK_SIZE   64
     * Themes
    /*A simple, impressive and very complete theme*/
    #define LV_USE_THEME_DEFAULT    1
    /*0: Light mode; 1: Dark mode*/
    # define LV_THEME_DEFAULT_DARK     0
    /*1: Enable grow on press*/
    # define LV_THEME_DEFAULT_GROW              1
    /*Default transition time in [ms]*/
    #endif /*LV_USE_THEME_DEFAULT*/
    /*An very simple them that is a good starting point for a custom theme*/
     #define LV_USE_THEME_BASIC    1
    /*A theme designed for monochrome displays*/
    #define LV_USE_THEME_MONO       1
     * Layouts
    /*A layout similar to Flexbox in CSS.*/
    #define LV_USE_FLEX     1
    /*A layout similar to Grid in CSS.*/
    #define LV_USE_GRID     1
    /*Enable the examples to be built with the library*/
    #define LV_BUILD_EXAMPLES   1
    /*--END OF LV_CONF_H--*/
    #endif /*LV_CONF_H*/
    #endif /*End of "Content enable"*/

    I'll try to play with this configuration, thanks for helping me!

  • I found something interesting:

    rst:0xc (SW_CPU_RESET),boot:0x17 (SPI_FAST_FLASH_BOOT)
    configsip: 0, SPIWP:0xee
    mode:DIO, clock div:1
    entry 0x400806a8
    Guru Meditation Error: Core  0 panic'ed (LoadProhibited). Exception was unhandled.
    Core 0 register dump:
    PC      : 0x400d864f  PS      : 0x00060b30  A0      : 0x800d7c45  A1      : 0x3ffe3a10  
    A2      : 0x00000000  A3      : 0x3ffba588  A4      : 0x00000120  A5      : 0x00003400  
    A6      : 0xffffffff  A7      : 0x00000000  A8      : 0x3ffcfdcc  A9      : 0x00000020  
    A10     : 0x00000000  A11     : 0x40086244  A12     : 0x00000000  A13     : 0x00000120  
    A14     : 0x00000001  A15     : 0x00000120  SAR     : 0x00000011  EXCCAUSE: 0x0000001c  
    EXCVADDR: 0x00000022  LBEG    : 0x400888a4  LEND    : 0x400888c0  LCOUNT  : 0xffffffff  
    ELF file SHA256: 0000000000000000
    Backtrace: 0x400d864f:0x3ffe3a10 0x400d7c42:0x3ffe3a30 0x400f2833:0x3ffe3a50 0x400d1585:0x3ffe3a70 0x400d15fe:0x3ffe3a90 0x400d1b9d:0x3ffe3ab0 0x4010a0ef:0x3ffe3bb0 0x40082c8d:0x3ffe3bd0 0x40082eb4:0x3ffe3c20 0x40079247:0x3ffe3c40 0x400792ad:0x3ffe3c70 0x400792b8:0x3ffe3ca0 0x40079465:0x3ffe3cc0 0x400806da:0x3ffe3df0 0x40007c15:0x3ffe3eb0 0x4000073d:0x3ffe3f20

    I think, I've a lot of things to learn about Cpp and its ecosystem before continue ^^'

  • Honestly I started off reading the LVGL online help and even though I am still learning I did not have much problem making the lib work on the Core2.
    However I spent some significant time before understanding the whole concept (probably because I am getting too old :) ) and you seem to be way more experienced than me so you will make it work quickly :)

    My GitHub project is private (because it might end up being commercially used) but if you want I can extract the minimum code I used to display something if it can help and make it public.

    By looking at the error (If I remember I got more or less the same) this looks like invalide pointer / memory allocation.

    I realized that just initializing everything for LVGL to work is a real pain (when you've never played with it) but after you've understood the basic concepts it comes much clearer.
    At this stage all basic things are working fine I am now moving on to Event management (button press, sliders move etc...).

    Btw you can also have a look at the EdgeLine application which is a kind of LVGL companion allowing you to WYSIWYG to C/Python code automatically for you. I am very bad at designing UIs so I am starting using it for my project and it can also help you understand the code which is generated.

  • Haha, thank you, but I started learning C/C++ this Monday 👀
    I'll try to investigate more about pointers /memory exceptions.
    Everything I'll do will be on my GitHub in public repositories, my aim is to create a Tamagotchi for my daughter ^^'

  • FYI, I correctly display a button, I have many things left to do next, like finding the reason why my DrawingBoard.cpp pointers are badly set, but in the end, you help me a lot!
    Thanks again!

    For people reading this, I'll do my best to improve my GitHub repository in order to have a simple example for M5Core, explaining which parameters must be configured in lv_conf.h :)

  • Hi Pierre,

    Sorry I don't feel I did much for you but my (real) work is really taking much of my time (even what is supposed to be my free time) and I wish I could have spent more time working this out with you.
    In any case my offer still stands, I can help you building up a simple template with comments for people to get started.
    I already spent much time on it and I believe I have understood all the basic concepts .
    As already said, now i need to go one step further with event management.
    Also I am quite used to code in C (this is the language I started with a loooong time ago) I am not an expert but at least I can understand the most of what I do :)
    Btw a good platform that I have adopted now since several months is VSCode + PIO...Very neat combination!

  • I will omit the details,
    Currently, M5Stack Core2 is working with LVGL v8.1.0 and Arduino IDE.


    About lv_conf.h
    The following three settings are required.

    lvgl-master v8.1.0 / src / lv_conf.h

    1. /* clang-format off */
      #if 1 /Set it to "1" to enable content/

    2. #define LV_COLOR_DEPTH 16

    3. #define LV_TICK_CUSTOM 1
      #if LV_TICK_CUSTOM
      #define LV_TICK_CUSTOM_INCLUDE "Arduino.h"