ESP32-2432S028 - Can't use SD card after initializing the UI

[AllanOricil]

@rzeldent

I isolated the problem to the UI initialization. If I remove it from my code entirely, I no longe have any issues reading/writing/append to files from the SD Card. Bellow you can see a simple evidence of the issue.

According to chat gpt, the issue might be related to the way the SPI is configured to the LCT, Toutch and SD card. There might exist a problem that does not let the 3 work together. Is there a way to bypass it?

Could you maybe create a lock/unlock for the display when the SD card wants to use the SPI?

[AllanOricil]

I further isolated the issue to smartdisplay_init(). After calling it, I can no longer use the sd card

[rzeldent]

Hi Allan,

I think it is caused by the SPI bus using the same SPI bus as the SD card.

In the file esp32-2432S028R.json you can trt to change the SPI host to : "'-D ILI9341_SPI_HOST=SPI2_HOST'"

Choices are:

SPI1_HOST=0,    ///< SPI1
SPI2_HOST=1,    ///< SPI2

#if SOC_SPI_PERIPH_NUM > 2
SPI3_HOST=2, ///< SPI3

Or change the SPI HOST for the SD card....

[AllanOricil]

ILI9341_SPI_HOST

@rzeldent
I'm using esp32-2432S028Rv3.json and there is no -D ILI9341_SPI_HOST=SPI2_HOST in extra_flags.

Besides that, inpecting esp32-2432S028R.json I saw that it has is already using SPI2_HOST

"'-D ILI9341_SPI_HOST=SPI2_HOST'",

v2 and v3 use this other one

"'-D ST7789_SPI_HOST=SPI2_HOST'",

Is this ST7789_SPI_HOST equivalent to ILI9341_SPI_HOST? Should I change it SPI1_HOST?

[rzeldent]

Yes, then try the "'-D ST7789_SPI_HOST=SPI2_HOST'" flag!

[AllanOricil]

But it was already set with SPI2_HOST

Look,
https://github.com/rzeldent/platformio-espressif32-sunton/blob/e864619f48bb75cfb7d1db3387ffa5897126aa5f/esp32-2432S028Rv3.json#L16

[rzeldent]

Yes, that is how it is now. But try to change this to SPI1_HOST or even SPI3_HOST....
The CS Card can also work in 2 modes, SPI or a 4 bits protocol. https://esp32.com/viewtopic.php?t=110

[AllanOricil]

None worked.

I changed -D ST7789_SPI_HOST=SPI2_HOST to -D ST7789_SPI_HOST=SPI3_HOST at ~/.platformio/platforms/espressif32/boards/esp32-2432S028Rv3.json, full clean, build, upload and monitor and got the same result

I changed -D ST7789_SPI_HOST=SPI2_HOST to -D ST7789_SPI_HOST=SPI1_HOST at ~/.platformio/platforms/espressif32/boards/esp32-2432S028Rv3.json, then did a full clean, build, upload and monitor and got the same result

[AllanOricil]

I also noticed that SPI3_HOST is already being used by the XPT2046 in all revisions of esp32-2432S028R.json

"'-D XPT2046_SPI_HOST=SPI3_HOST'",

[AllanOricil]

I just tried to free the SPI2_HOST and SPI3_HOST to let the sd card use them, and got the same result. Maybe I did it wrong?

// all the following operations work
create_dir(SD, "/test3");
write_file(SD, "/test3/test.txt", "bla");
read_file(SD, "/test3/test.txt");

// SETUP UI
smartdisplay_init();
  
pinMode(TF_CS, OUTPUT);
pinMode(ST7789_SPI_CONFIG_CS_GPIO_NUM, OUTPUT);

digitalWrite(TF_CS, LOW); //enable SD card => option as it was already HIGH in the setup
digitalWrite(ST7789_SPI_CONFIG_CS_GPIO_NUM, HIGH); // disable toutch or the screen, you can change to the toutch pin here

// THIS FAILS even when disabling touch or lcd CS_GPIO pins
read_file(SD, "/test3/test.txt");

[AllanOricil]

@rzeldent
I changed both lcd and touch to use SPI2_HOST and then set the sd card to use SPI3_HOST and it worked. In the board esp32-2432S028Rv3.json I added the following changes:

"'-D ST7789_SPI_HOST=SPI2_HOST'",
"'-D XPT2046_SPI_HOST=SPI2_HOST'",
"'-D TF_SPI_HOST=SPI3_HOST'",

It was the only thing I could do to make it work. I also tried changing both to SPI3_HOST, and le tthe SD card using SPI2_HOST, but this setup did not work. However, I can no longer use the touch, and I need it. So, I think you have to create some sort of multiplexing to allow both touch and screen share the same SPI host. At least, that was what chat gpt told me. Is he right?

Here is the evidence that proves I can now read from the SD card after calling smartdisplay_init. However, I got an error, possibly related to the touch sensor, and I can no longer use the touch feature.

[AllanOricil]

I have also tried this combination, and my code breaks at runtime. Apparently, SPI1_HOST can only be used to flash.

"'-D ST7789_SPI_HOST=SPI2_HOST'",
"'-D XPT2046_SPI_HOST=SPI1_HOST'",
"'-D TF_SPI_HOST=SPI3_HOST'",

This means that in order to use the SD card, it will be necessary to have it sharing the same SPI_HOST with another peripheral. And, based on my tests, I believe the touch is the best option. However, it will be necessary to implement some sort of multipler. Is this possible?

[AllanOricil]

I also tried this chatgpt suggestion. Put both touch and SD card on the same SPI3_HOST, then used the following code when trying to interact with the sd card. And again, it did not work.

digitalWrite(XPT2046_SPI_CONFIG_CS_GPIO_NUM, HIGH); // Deselect touch sensor 
mySPI.beginTransaction(SPISettings(SPI_CLOCK_DIV2, MSBFIRST, SPI_MODE0));
digitalWrite(TF_CS, LOW); // Select SD card
read_file(SD, "/test3/test.txt");
// Further file operations
digitalWrite(TF_CS, HIGH); // Deselect SD card
mySPI.endTransaction();
digitalWrite(XPT2046_SPI_CONFIG_CS_GPIO_NUM, LOW);

[AllanOricil]

@rzeldent
Im blocked until this issue could be resolved. I tried everything I could have asked to chatgpt. I ran out of questions D:

[AllanOricil]

According to chat gpt I have no option. This board was created without support for using SD card while touch and lcd are using the available spi buses. If you find a solution @rzeldent I would appreciate. I don't believe chat gpt is fully right.