Add extra fonts to lvgl does not work as expected

[ste7anste7an]

Adding fonts

I made this change in `lvgl_micropython/lib/lv_conf.h':

/*Montserrat fonts with ASCII range and some symbols using bpp = 4
 *https://fonts.google.com/specimen/Montserrat*/
#define LV_FONT_MONTSERRAT_8  0
#define LV_FONT_MONTSERRAT_10 0
#define LV_FONT_MONTSERRAT_12 1
#define LV_FONT_MONTSERRAT_14 1
#define LV_FONT_MONTSERRAT_16 1
#define LV_FONT_MONTSERRAT_18 0
#define LV_FONT_MONTSERRAT_20 1
#define LV_FONT_MONTSERRAT_22 0
#define LV_FONT_MONTSERRAT_24 0
#define LV_FONT_MONTSERRAT_26 1
#define LV_FONT_MONTSERRAT_28 0
#define LV_FONT_MONTSERRAT_30 0
#define LV_FONT_MONTSERRAT_32 1
#define LV_FONT_MONTSERRAT_34 0
#define LV_FONT_MONTSERRAT_36 0
#define LV_FONT_MONTSERRAT_38 1
#define LV_FONT_MONTSERRAT_40 0
#define LV_FONT_MONTSERRAT_42 0
#define LV_FONT_MONTSERRAT_44 1
#define LV_FONT_MONTSERRAT_46 0
#define LV_FONT_MONTSERRAT_48 0

I comile the firmware resulting in lvgl_micropy_ESP32_GENERIC-4.bin

When I do: strings lvgl_micropy_ESP32_GENERIC-4.bin |grep font_montserrat I get:

font_montserrat_12
font_montserrat_14
font_montserrat_16
font_montserrat_20
font_montserrat_26
font_montserrat_32
font_montserrat_38
font_montserrat_44

But when I run this little program:

import lvgl
methods=dir(lvgl)
for m in methods:
    if m[:9]=='font_mont':
        print(m)

I only see:

font_montserrat_12
font_montserrat_14
font_montserrat_16

• Make: ESP32
• Model: ESP32-PICO-V3-02 (revision 3) wuth 2MByte of PSRAM, but I did not use PSRAM.

I need to know the OS and OS version of the machine that compiled the binary. If using a VM then I need to know the OS and OS version the VM is running. (WSL == VM)

• OS: Ubuntu 22.04.3 LTS

Build Command

python3 make.py esp32 BOARD=ESP32_GENERIC DISPLAY=ili9341 DISPLAY=st7789 INDEV=xpt2046 INDEV=cst816s

[kdschlosser]

and where are you turning the fonts on at? You need to change the lv_conf.h file located in the libs directory to change the LVGL settings.

It looks like you are doing it there... It should be compiling without any problems by doing that.

Look in the micropython build folder after you compile and look for the generated C source file for LVGL. Then search that file for your fonts and see if they are actually being linked to micropython.

the build folder is libs/micropython/ports/esp32/build_*

[ste7anste7an]

Thank your for you suggestion. I indeed see the fonts included in lv_mp.c:

lvgl_micropython/lib/micropython/ports/esp32/build-ESP32_GENERIC$ grep montserrat *.c
lv_mp.c: * lvgl lv_font_montserrat_12 global definitions
lv_mp.c:static const mp_lv_struct_t mp_lv_font_montserrat_12 = {
lv_mp.c:    (lv_font_t*)&lv_font_montserrat_12
lv_mp.c: * lvgl lv_font_montserrat_14 global definitions
lv_mp.c:static const mp_lv_struct_t mp_lv_font_montserrat_14 = {
lv_mp.c:    (lv_font_t*)&lv_font_montserrat_14
lv_mp.c: * lvgl lv_font_montserrat_16 global definitions
lv_mp.c:static const mp_lv_struct_t mp_lv_font_montserrat_16 = {
lv_mp.c:    (lv_font_t*)&lv_font_montserrat_16
lv_mp.c: * lvgl lv_font_montserrat_20 global definitions
lv_mp.c:static const mp_lv_struct_t mp_lv_font_montserrat_20 = {
lv_mp.c:    (lv_font_t*)&lv_font_montserrat_20
lv_mp.c: * lvgl lv_font_montserrat_26 global definitions
lv_mp.c:static const mp_lv_struct_t mp_lv_font_montserrat_26 = {
lv_mp.c:    (lv_font_t*)&lv_font_montserrat_26
lv_mp.c: * lvgl lv_font_montserrat_32 global definitions
lv_mp.c:static const mp_lv_struct_t mp_lv_font_montserrat_32 = {
lv_mp.c:    (lv_font_t*)&lv_font_montserrat_32
lv_mp.c: * lvgl lv_font_montserrat_38 global definitions
lv_mp.c:static const mp_lv_struct_t mp_lv_font_montserrat_38 = {
lv_mp.c:    (lv_font_t*)&lv_font_montserrat_38
lv_mp.c: * lvgl lv_font_montserrat_44 global definitions
lv_mp.c:static const mp_lv_struct_t mp_lv_font_montserrat_44 = {
lv_mp.c:    (lv_font_t*)&lv_font_montserrat_44
lv_mp.c:    { MP_ROM_QSTR(MP_QSTR_font_montserrat_12), MP_ROM_PTR(&mp_lv_font_montserrat_12) },
lv_mp.c:    { MP_ROM_QSTR(MP_QSTR_font_montserrat_14), MP_ROM_PTR(&mp_lv_font_montserrat_14) },
lv_mp.c:    { MP_ROM_QSTR(MP_QSTR_font_montserrat_16), MP_ROM_PTR(&mp_lv_font_montserrat_16) },
lv_mp.c:    { MP_ROM_QSTR(MP_QSTR_font_montserrat_20), MP_ROM_PTR(&mp_lv_font_montserrat_20) },
lv_mp.c:    { MP_ROM_QSTR(MP_QSTR_font_montserrat_26), MP_ROM_PTR(&mp_lv_font_montserrat_26) },
lv_mp.c:    { MP_ROM_QSTR(MP_QSTR_font_montserrat_32), MP_ROM_PTR(&mp_lv_font_montserrat_32) },
lv_mp.c:    { MP_ROM_QSTR(MP_QSTR_font_montserrat_38), MP_ROM_PTR(&mp_lv_font_montserrat_38) },
lv_mp.c:    { MP_ROM_QSTR(MP_QSTR_font_montserrat_44), MP_ROM_PTR(&mp_lv_font_montserrat_44) },

But still, I do not see all the fonts in micropython. When I do:

include lvgl

and type:

>>> lvgl.font_montserrat_1 <TAB>
font_montserrat_12              font_montserrat_14
font_montserrat_16

I only see these three fonts.

When I only include

#define LV_FONT_MONTSERRAT_14 1

in lv_conf.h, I still see these fonts in the firmware:

>>> lvgl.font_montserrat_1 <TAB>
font_montserrat_12              font_montserrat_14
font_montserrat_16

It looks like the lvgl config gets overwritten by some default file.

[kdschlosser]

I think I know what may be causing the problem. You have to give me a bit to look into it.

[ste7anste7an]

Could you guide me in the direction I have to look to change the default fonts that are incorporated in the firmware? If you could explain what would cause the problem, I could look for myself to fix it.

[dudasdavid]

I'm also using additional fonts, even adding custom fonts to the build and it works without any problem, are you sure that after compiling it you are flashing the right firmware? At startup you see the build date, does it match with your real build date?

Anyway, without further details I cannot really help more, but I wanted to mention that you can load fonts dynamically at runtime, you don't have to pack them into your build.

You can load your fonts from .bin files using the fs_driver like this:

    import fs_driver
    fs_drv = lv.fs_drv_t()
    fs_driver.fs_register(fs_drv, 'S')
    custom_font = lv.binfont_create("S:/fonts/font_consolas_14.bin")
    table.set_style_text_font(custom_font, 0) 

You can compile your own fonts to .bin using LVGL's online font converter:
https://lvgl.io/tools/fontconverter

[ste7anste7an]

Good sugestion! I will double check that I run the firmware that has been build.