ESP32 Arduino format an SD card

format_sdcard.c

#include "ff.h"
#include "vfs_fat_internal.h"

/**
 * Usage:
 *
 * Arduino:
 *   SD.begin();
 *   format_sdcard();
 * 
 * ESP-IDF:
 *   See https://github.com/espressif/esp-idf/blob/b63ec47238fd6aa6eaa59f7ad3942cbdff5fcc1f/examples/storage/sd_card/sdmmc/main/sd_card_example_main.c#L75
 *   esp_vfs_fat_sdmmc_mount(mount_point, &host, &slot_config, &mount_config, &card);
 *   format_sdcard();
 *
 * Then proceed without remounting.
 */
esp_err_t format_sdcard() {
    char drv[3] = {'0', ':', 0};
    const size_t workbuf_size = 4096;
    void* workbuf = NULL;
    esp_err_t err = ESP_OK;
    ESP_LOGW("sdcard", "Formatting the SD card");

    size_t allocation_unit_size = 16 * 1024;
    int sector_size_default = 512;

    workbuf = ff_memalloc(workbuf_size);
    if (workbuf == NULL) {
        return ESP_ERR_NO_MEM;
    }

    size_t alloc_unit_size = esp_vfs_fat_get_allocation_unit_size(
                sector_size_default,
                allocation_unit_size);

#if (ESP_IDF_VERSION_MAJOR < 5)
    FRESULT res = f_mkfs(drv, FM_ANY, alloc_unit_size, workbuf, workbuf_size);
#else
    const MKFS_PARM opt = {(BYTE)FM_ANY, 0, 0, 0, alloc_unit_size};
    FRESULT res = f_mkfs(drv, &opt, workbuf, workbuf_size);
#endif  /* ESP_IDF_VERSION_MAJOR */
    if (res != FR_OK) {
        err = ESP_FAIL;
        ESP_LOGE("sdcard", "f_mkfs failed (%d)", res);
    }

    free(workbuf);

    ESP_LOGI("sdcard", "Successfully formatted the SD card");

    return err;
}

It does format the card to FAT32 4096 (see workbuf_size).

Thank you!

That sounds very interesting. The Dwin display is updated via SD card.

And I had already done a test with ESP8266 on a webserver and FTP to manipulate files on the SD card, and the idea was to use the SD card in the DFPlayer Mini.

But now there is the possibility of updating the Dwin display using the ESP32.

The card must be formatted in FAT32 and 4096. Is it possible to format in FAT32?

Just out of curiosity, I found a W25Q128 memory on the Dwin display (DMG80480Y070_02NN T5L0 IC). The data is saved in this memory in virtual partitions of 256kB, so it might be interesting for the ESP32 to program the data from the W25Q128 memory, which is SPI (if the data is not encrypted, which I believe it is not, so as not to reduce performance, I'm still going to see if I can check that).