How to Run a Demo with M5stack

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1

Description

Good,day!
I want to know how to run a demo in M5stack.

What MCU/Processor/Board and compiler are you using?

M5stack , VSCode with PlatformIO , LittlevGL(v6)

What do you want to achieve?

I want to use a LittlevGL in the screen that is implemented in the M5stack.

What have you tried so far?

I matched the pin assignment of the TFT_eSPI library to the M5stack.
However, I can only see the sandstorm.

Code to reproduce

TFT_eSPI/User_Setup.h
// For the M5Stack module use these #define lines
#define TFT_MISO 19
#define TFT_MOSI 23
#define TFT_SCLK 18
#define TFT_CS   14  // Chip select control pin
#define TFT_DC   27  // Data Command control pin
#define TFT_RST  33  // Reset pin (could connect to Arduino RESET pin)
#define TFT_BL   32  // LED back-light (required for M5Stack)

Screenshot and/or video

砂嵐
砂嵐4032×3024 2.07 MB

2

Hi,
AFAIK the M5 has special version of the TFT_eSPI library. Are you using their special version or the standard one?

3

Thanks, Pablo.
I didn’t even know a special version existed.
I’ve been using the same TFT_ eSPI library for some time now.
It’s probably the standard version.
Where’s the special TFT_eSPI library?

4

So I’ve take simple look to the TFT_eSPI repo and… look ma’ what I’ve found: https://github.com/Bodmer/TFT_eSPI/blob/master/User_Setups/Setup12_M5Stack.h then I’ve used my friend Google to search for M5Stack library source and he found this https://github.com/m5stack/M5Stack/blob/master/src/M5Display.cpp so I was actually wrong - the is no special version of the library, but special user configuration in TFT_eSPI and special additional setup.

5

That’s great!!!
I checked “Setup12.M5stack.h” and it looks like I needed #define M5STACK.
When I added it, it was no longer a sandstorm.
However, the night theme is not adapted.I think the colors are reversed.

image
image824×805 191 KB

Do you know anything about this?

6

Unfortunately I don’t have any M5Stack, but can it be this https://github.com/m5stack/M5Stack/blob/e8085b06f26d59014cdb8950104aac33293edda6/src/M5Display.cpp#L36 ?

7

I referred to it, but it seems a bit esoteric to me.
The M5stack’s display driver appears to be a special ILI9341.
It seems to be using BGR for color representation, but I was able to fix that by setting up the TFT_eSPI library.
The problem is that the positives and negatives of the colors are reversed.

Is it still a setting on the TFT_ eSPI side?

8

I’m unable to say if it is in TFT_eSPI or in the color type in LVGL. You probably have to test the right colors with simple fill screen or something like this.

9

I have once again made a comparison with the project you told me about.
As a result, I found that I was hitting the registers directly with the display driver code.
I have mimicked it in my library.
image

image
image612×596 111 KB

With that, the theme color has been successfully returned!
Now you can play with M5stack. Thanks to you, Pablo!

1 Like
10

Hi,
I’m trying to get my m5stack together with vscode + platformio running. But could not find a example to give me a kickstart.
I failed to transfer the esp32 example to platformio. Failed also with transfer the platformio example from stm32 to esp32. (Compiles for stm32 but not for esp32)
I’m not an expert - especially not for build environments.
Any hint where I can get a fresh quickstart?

11

hello I want show a button in lcd 800*480 and lvgl v7.11 my code is:

static lv_disp_buf_t disp_buf;
static lv_disp_drv_t disp_drv;
static lv_color_t buf[LV_HOR_RES_MAX * LV_VER_RES_MAX / 10];

uint16_t* LCD_FB=(uint16_t*)0xC0000000; // LCD FRAME Buffer

//**********************************************************************

lv_init();     

lv_disp_buf_init(&disp_buf, buf, NULL, LV_HOR_RES_MAX*10);
lv_disp_drv_init(&disp_drv);

disp_drv.flush_cb = my_disp_flush;
disp_drv.buffer = &disp_buf;

disp_drv.hor_res = LV_HOR_RES_MAX; /Set the horizontal resolution of the display/
disp_drv.ver_res = LV_VER_RES_MAX; /Set the vertical resolution of the display/
lv_disp_drv_register(&disp_drv);

lv_obj_t * btn = lv_btn_create(lv_scr_act(), NULL); /Add a button the current screen/
lv_obj_set_pos(btn, 10, 10); /Set its position/
lv_obj_set_size(btn, 120, 50);

//*************************************************************

void my_disp_flush(lv_disp_drv_t * disp, const lv_area_t * area, lv_color_t * color_p)
{
int32_t x, y;
for(y = area->y1; y <= area->y2; y++) {
for(x = area->x1; x <= area->x2; x++) {
//set_pixel(x, y, color_p); / Put a pixel to the display.*/
LCD_FB[x+(y * LV_HOR_RES_MAX)]=(color_p->full);
color_p++;
}
}

lv_disp_flush_ready(disp);         /* Indicate you are ready with the flushing*/

}

//*************************************************************

but my lcd show it :

۲۰۲۱۰۹۲۱_۱۱۳۶۳۶
۲۰۲۱۰۹۲۱_۱۱۳۶۳۶3276×2000 2.22 MB

What do you think is the problem?