SD MMC

About

Note

This is a work in progress project and this section is still missing. If you want to contribute, please see the Contributions Guide.

Example

To get started with SD_MMC, you can try:

SDMMC Test

/*
 * pin 1 - D2                |  Micro SD card     |
 * pin 2 - D3                |                   /
 * pin 3 - CMD               |                  |__
 * pin 4 - VDD (3.3V)        |                    |
 * pin 5 - CLK               | 8 7 6 5 4 3 2 1   /
 * pin 6 - VSS (GND)         | ▄ ▄ ▄ ▄ ▄ ▄ ▄ ▄  /
 * pin 7 - D0                | ▀ ▀ █ ▀ █ ▀ ▀ ▀ |
 * pin 8 - D1                |_________________|
 *                             ║ ║ ║ ║ ║ ║ ║ ║
 *                     ╔═══════╝ ║ ║ ║ ║ ║ ║ ╚═════════╗
 *                     ║         ║ ║ ║ ║ ║ ╚══════╗    ║
 *                     ║   ╔═════╝ ║ ║ ║ ╚═════╗  ║    ║
 * Connections for     ║   ║   ╔═══╩═║═║═══╗   ║  ║    ║
 * full-sized          ║   ║   ║   ╔═╝ ║   ║   ║  ║    ║
 * SD card             ║   ║   ║   ║   ║   ║   ║  ║    ║
 * ESP32-P4 Func EV | 40  39  GND  43 3V3 GND  44 43  42  | SLOT 0 (IO_MUX)
 * ESP32-S3 DevKit  | 21  47  GND  39 3V3 GND  40 41  42  |
 * ESP32-S3-USB-OTG | 38  37  GND  36 3V3 GND  35 34  33  |
 * ESP32            |  4   2  GND  14 3V3 GND  15 13  12  |
 * Pin name         | D1  D0  VSS CLK VDD VSS CMD D3  D2  |
 * SD pin number    |  8   7   6   5   4   3   2   1   9 /
 *                  |                                  █/
 *                  |__▍___▊___█___█___█___█___█___█___/
 * WARNING: ALL data pins must be pulled up to 3.3V with an external 10k Ohm resistor!
 * Note to ESP32 pin 2 (D0): Add a 1K Ohm pull-up resistor to 3.3V after flashing
 *
 * SD Card | ESP32
 *    D2       12
 *    D3       13
 *    CMD      15
 *    VSS      GND
 *    VDD      3.3V
 *    CLK      14
 *    VSS      GND
 *    D0       2  (add 1K pull up after flashing)
 *    D1       4
 *
 *    For more info see file README.md in this library or on URL:
 *    https://github.com/espressif/arduino-esp32/tree/master/libraries/SD_MMC
 */

#include "FS.h"
#include "SD_MMC.h"

#ifdef CONFIG_IDF_TARGET_ESP32S3
// Default pins for ESP-S3
// Warning: ESP32-S3-WROOM-2 is using most of the default GPIOs (33-37) to interface with on-board OPI flash.
//   If the SD_MMC is initialized with default pins it will result in rebooting loop - please
//   reassign the pins elsewhere using the mentioned command `setPins`.
// Note: ESP32-S3-WROOM-1 does not have GPIO 33 and 34 broken out.
// Note: if it's ok to use default pins, you do not need to call the setPins
int clk = 36;
int cmd = 35;
int d0 = 37;
int d1 = 38;
int d2 = 33;
int d3 = 39;  // GPIO 34 is not broken-out on ESP32-S3-DevKitC-1 v1.1
#endif

void listDir(fs::FS &fs, const char *dirname, uint8_t levels) {
  Serial.printf("Listing directory: %s\n", dirname);

  File root = fs.open(dirname);
  if (!root) {
    Serial.println("Failed to open directory");
    return;
  }
  if (!root.isDirectory()) {
    Serial.println("Not a directory");
    return;
  }

  File file = root.openNextFile();
  while (file) {
    if (file.isDirectory()) {
      Serial.print("  DIR : ");
      Serial.println(file.name());
      if (levels) {
        listDir(fs, file.path(), levels - 1);
      }
    } else {
      Serial.print("  FILE: ");
      Serial.print(file.name());
      Serial.print("  SIZE: ");
      Serial.println(file.size());
    }
    file = root.openNextFile();
  }
}

void createDir(fs::FS &fs, const char *path) {
  Serial.printf("Creating Dir: %s\n", path);
  if (fs.mkdir(path)) {
    Serial.println("Dir created");
  } else {
    Serial.println("mkdir failed");
  }
}

void removeDir(fs::FS &fs, const char *path) {
  Serial.printf("Removing Dir: %s\n", path);
  if (fs.rmdir(path)) {
    Serial.println("Dir removed");
  } else {
    Serial.println("rmdir failed");
  }
}

void readFile(fs::FS &fs, const char *path) {
  Serial.printf("Reading file: %s\n", path);

  File file = fs.open(path);
  if (!file) {
    Serial.println("Failed to open file for reading");
    return;
  }

  Serial.print("Read from file: ");
  while (file.available()) {
    Serial.write(file.read());
  }
}

void writeFile(fs::FS &fs, const char *path, const char *message) {
  Serial.printf("Writing file: %s\n", path);

  File file = fs.open(path, FILE_WRITE);
  if (!file) {
    Serial.println("Failed to open file for writing");
    return;
  }
  if (file.print(message)) {
    Serial.println("File written");
  } else {
    Serial.println("Write failed");
  }
}

void appendFile(fs::FS &fs, const char *path, const char *message) {
  Serial.printf("Appending to file: %s\n", path);

  File file = fs.open(path, FILE_APPEND);
  if (!file) {
    Serial.println("Failed to open file for appending");
    return;
  }
  if (file.print(message)) {
    Serial.println("Message appended");
  } else {
    Serial.println("Append failed");
  }
}

void renameFile(fs::FS &fs, const char *path1, const char *path2) {
  Serial.printf("Renaming file %s to %s\n", path1, path2);
  if (fs.rename(path1, path2)) {
    Serial.println("File renamed");
  } else {
    Serial.println("Rename failed");
  }
}

void deleteFile(fs::FS &fs, const char *path) {
  Serial.printf("Deleting file: %s\n", path);
  if (fs.remove(path)) {
    Serial.println("File deleted");
  } else {
    Serial.println("Delete failed");
  }
}

void testFileIO(fs::FS &fs, const char *path) {
  File file = fs.open(path);
  static uint8_t buf[512];
  size_t len = 0;
  uint32_t start = millis();
  uint32_t end = start;
  if (file) {
    len = file.size();
    size_t flen = len;
    start = millis();
    while (len) {
      size_t toRead = len;
      if (toRead > 512) {
        toRead = 512;
      }
      file.read(buf, toRead);
      len -= toRead;
    }
    end = millis() - start;
    Serial.printf("%u bytes read for %lu ms\n", flen, end);
    file.close();
  } else {
    Serial.println("Failed to open file for reading");
  }

  file = fs.open(path, FILE_WRITE);
  if (!file) {
    Serial.println("Failed to open file for writing");
    return;
  }

  size_t i;
  start = millis();
  for (i = 0; i < 2048; i++) {
    file.write(buf, 512);
  }
  end = millis() - start;
  Serial.printf("%u bytes written for %lu ms\n", 2048 * 512, end);
  file.close();
}

void setup() {
  Serial.begin(115200);
  /*
    // If you want to change the pin assignment or you get an error that some pins
    // are not assigned on ESP32-S3/ESP32-P4 uncomment this block and the appropriate
    // line depending if you want to use 1-bit or 4-bit line.
    // Please note that ESP32 does not allow pin change and setPins() will always fail.
    //if(! SD_MMC.setPins(clk, cmd, d0)){
    //if(! SD_MMC.setPins(clk, cmd, d0, d1, d2, d3)){
    //    Serial.println("Pin change failed!");
    //    return;
    //}
  */

  if (!SD_MMC.begin()) {
    Serial.println("Card Mount Failed");
    return;
  }
  uint8_t cardType = SD_MMC.cardType();

  if (cardType == CARD_NONE) {
    Serial.println("No SD_MMC card attached");
    return;
  }

  Serial.print("SD_MMC Card Type: ");
  if (cardType == CARD_MMC) {
    Serial.println("MMC");
  } else if (cardType == CARD_SD) {
    Serial.println("SDSC");
  } else if (cardType == CARD_SDHC) {
    Serial.println("SDHC");
  } else {
    Serial.println("UNKNOWN");
  }

  uint64_t cardSize = SD_MMC.cardSize() / (1024 * 1024);
  Serial.printf("SD_MMC Card Size: %lluMB\n", cardSize);

  listDir(SD_MMC, "/", 0);
  createDir(SD_MMC, "/mydir");
  listDir(SD_MMC, "/", 0);
  removeDir(SD_MMC, "/mydir");
  listDir(SD_MMC, "/", 2);
  writeFile(SD_MMC, "/hello.txt", "Hello ");
  appendFile(SD_MMC, "/hello.txt", "World!\n");
  readFile(SD_MMC, "/hello.txt");
  deleteFile(SD_MMC, "/foo.txt");
  renameFile(SD_MMC, "/hello.txt", "/foo.txt");
  readFile(SD_MMC, "/foo.txt");
  testFileIO(SD_MMC, "/test.txt");
  Serial.printf("Total space: %lluMB\n", SD_MMC.totalBytes() / (1024 * 1024));
  Serial.printf("Used space: %lluMB\n", SD_MMC.usedBytes() / (1024 * 1024));
}

void loop() {
  delay(10);
}

Complete list of SD MMC examples.