ESP_LOGI(TAG, "Mounting filesystem"); ret = esp_vfs_fat_sdmmc_mount(mount_point, &host, &slot_config, &mount_config, &card);
if (ret != ESP_OK) { if (ret == ESP_FAIL) { ESP_LOGE(TAG, "Failed to mount filesystem. " "If you want the card to be formatted, set the EXAMPLE_FORMAT_IF_MOUNT_FAILED menuconfig option."); } else { ESP_LOGE(TAG, "Failed to initialize the card (%s). " "Make sure SD card lines have pull-up resistors in place.", esp_err_to_name(ret)); } return; } ESP_LOGI(TAG, "Filesystem mounted");
// This example uses SDMMC peripheral to communicate with SD card. #include<string.h> #include<sys/unistd.h> #include<sys/stat.h> #include"esp_vfs_fat.h" #include"sdmmc_cmd.h" #include"driver/sdmmc_host.h"
#define EXAMPLE_MAX_CHAR_SIZE 64
staticconstchar *TAG = "example";
#define MOUNT_POINT "/sdcard"
staticesp_err_ts_example_write_file(constchar *path, char *data) { ESP_LOGI(TAG, "Opening file %s", path); FILE *f = fopen(path, "w"); if (f == NULL) { ESP_LOGE(TAG, "Failed to open file for writing"); return ESP_FAIL; } fprintf(f, data); fclose(f); ESP_LOGI(TAG, "File written");
return ESP_OK; }
staticesp_err_ts_example_read_file(constchar *path) { ESP_LOGI(TAG, "Reading file %s", path); FILE *f = fopen(path, "r"); if (f == NULL) { ESP_LOGE(TAG, "Failed to open file for reading"); return ESP_FAIL; } char line[EXAMPLE_MAX_CHAR_SIZE]; fgets(line, sizeof(line), f); fclose(f);
// Options for mounting the filesystem. // If format_if_mount_failed is set to true, SD card will be partitioned and // formatted in case when mounting fails. esp_vfs_fat_sdmmc_mount_config_t mount_config = { // 此选项用于开关SD卡挂载失败后是否格式化 #ifdef CONFIG_EXAMPLE_FORMAT_IF_MOUNT_FAILED .format_if_mount_failed = true, #else .format_if_mount_failed = false, #endif// EXAMPLE_FORMAT_IF_MOUNT_FAILED .max_files = 5, .allocation_unit_size = 16 * 1024};
// Use settings defined above to initialize SD card and mount FAT filesystem. // Note: esp_vfs_fat_sdmmc/sdspi_mount is all-in-one convenience functions. // Please check its source code and implement error recovery when developing // production applications.
ESP_LOGI(TAG, "Using SDMMC peripheral");
// By default, SD card frequency is initialized to SDMMC_FREQ_DEFAULT (20MHz) // For setting a specific frequency, use host.max_freq_khz (range 400kHz - 40MHz for SDMMC) // Example: for fixed frequency of 10MHz, use host.max_freq_khz = 10000; sdmmc_host_t host = SDMMC_HOST_DEFAULT();
// This initializes the slot without card detect (CD) and write protect (WP) signals. // Modify slot_config.gpio_cd and slot_config.gpio_wp if your board has these signals. sdmmc_slot_config_t slot_config = SDMMC_SLOT_CONFIG_DEFAULT();
// Set bus width to use: #ifdef CONFIG_EXAMPLE_SDMMC_BUS_WIDTH_4 slot_config.width = 4; #else slot_config.width = 1; #endif
// On chips where the GPIOs used for SD card can be configured, set them in // the slot_config structure: #ifdef CONFIG_SOC_SDMMC_USE_GPIO_MATRIX slot_config.clk = CONFIG_EXAMPLE_PIN_CLK; slot_config.cmd = CONFIG_EXAMPLE_PIN_CMD; slot_config.d0 = CONFIG_EXAMPLE_PIN_D0; #ifdef CONFIG_EXAMPLE_SDMMC_BUS_WIDTH_4 slot_config.d1 = CONFIG_EXAMPLE_PIN_D1; slot_config.d2 = CONFIG_EXAMPLE_PIN_D2; slot_config.d3 = CONFIG_EXAMPLE_PIN_D3; #endif// CONFIG_EXAMPLE_SDMMC_BUS_WIDTH_4 #endif// CONFIG_SOC_SDMMC_USE_GPIO_MATRIX
// Enable internal pullups on enabled pins. The internal pullups // are insufficient however, please make sure 10k external pullups are // connected on the bus. This is for debug / example purpose only. slot_config.flags |= SDMMC_SLOT_FLAG_INTERNAL_PULLUP;
ESP_LOGI(TAG, "Mounting filesystem"); ret = esp_vfs_fat_sdmmc_mount(mount_point, &host, &slot_config, &mount_config, &card);
if (ret != ESP_OK) { if (ret == ESP_FAIL) { ESP_LOGE(TAG, "Failed to mount filesystem. " "If you want the card to be formatted, set the EXAMPLE_FORMAT_IF_MOUNT_FAILED menuconfig option."); } else { ESP_LOGE(TAG, "Failed to initialize the card (%s). " "Make sure SD card lines have pull-up resistors in place.", esp_err_to_name(ret)); } return; } ESP_LOGI(TAG, "Filesystem mounted");
// Card has been initialized, print its properties sdmmc_card_print_info(stdout, card);
// Use POSIX and C standard library functions to work with files:
// First create a file. constchar *file_hello = MOUNT_POINT "/hello.txt"; char data[EXAMPLE_MAX_CHAR_SIZE]; snprintf(data, EXAMPLE_MAX_CHAR_SIZE, "%s %s!\n", "Hello", card->cid.name); ret = s_example_write_file(file_hello, data); if (ret != ESP_OK) { return; }
constchar *file_foo = MOUNT_POINT "/foo.txt"; // Check if destination file exists before renaming structstatst; if (stat(file_foo, &st) == 0) { // Delete it if it exists unlink(file_foo); }
// Rename original file ESP_LOGI(TAG, "Renaming file %s to %s", file_hello, file_foo); if (rename(file_hello, file_foo) != 0) { ESP_LOGE(TAG, "Rename failed"); return; }
ret = s_example_read_file(file_foo); if (ret != ESP_OK) { return; }
// Format FATFS ret = esp_vfs_fat_sdcard_format(mount_point, card); if (ret != ESP_OK) { ESP_LOGE(TAG, "Failed to format FATFS (%s)", esp_err_to_name(ret)); return; }
if (stat(file_foo, &st) == 0) { ESP_LOGI(TAG, "file still exists"); return; } else { ESP_LOGI(TAG, "file doesnt exist, format done"); }
