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-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"

// 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

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 assigment on ESP32-S3 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 will always fail.
    //if(! setPins(clk, cmd, d0)){
    //if(! 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(){

}

Complete list of SD MMC examples.