Block device class for creating a block device to access a SD/MMC card via SD/MMC interface on DISCO_F746NG

Dependencies:   BSP_DISCO_F746NG

Dependents:   DISCO-F746NG_BLOCK_DEVICE_SDCARD DISCO-F746NG_BLOCK_DEVICE_WITH_FAT_FILESYSTEM_ON_SDCARD SDReaderTest

Block device class for creating a block device to access a SD/MMC card via SD/MMC interface on DISCO_F746NG development board. This block device API provides an interface for access to block-based storage. You can use a block device to back a full file system or write to it directly. More about Block Devices

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Simple example how to use the block device

/* Example file of using SD/MMC Block device Library for MBED-OS
 * Copyright 2017 Roy Krikke
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#include "mbed.h"
#include "SDBlockDeviceDISCOF746NG.h"

DigitalOut led (LED1);

// Instantiate the Block Device for sd card on DISCO-F746NG
SDBlockDeviceDISCOF746NG bd;
uint8_t block[512] = "Hello World!\n";

int
main ()
{
    Serial pc (SERIAL_TX, SERIAL_RX);
    pc.baud(115200);
    printf("Start\n");

    // Call the SDBlockDeviceDISCOF746NG instance initialisation method.
    printf("sd card init...\n");
    if (0 != bd.init()) {
        printf("Init failed \n");
        return -1;
    }

    printf("sd size: %llu\n", bd.size());
    printf("sd read size: %llu\n", bd.get_read_size());
    printf("sd program size: %llu\n", bd.get_program_size());
    printf("sd erase size: %llu\n\n", bd.get_erase_size());

    printf("sd erase...\n");
    if (0 != bd.erase (0, bd.get_erase_size())) {
        printf("Error Erasing block \n");
    }

    // Write some the data block to the device
    printf("sd write: %s\n", block);
    if (0 == bd.program(block, 0, 512)) {
        // read the data block from the device
        printf("sd read: ");
        if (0 == bd.read(block, 0, 512)) {
            // print the contents of the block
            printf("%s", block);
        }
    }

////////////////////////////////////////////////////////////////////////////////

    for(int i; i < 10; i++) {
        memset(block, i, sizeof(block));
        if(bd.program(block, (i*512), sizeof(block)) != 0) {
            printf("Error at: %i\r\n",i);
        }
    }

    if(bd.erase((1*512), sizeof(block)) != 0) {
        printf("Error Erasing block\n");
    }

    memset(block, 'x', sizeof(block));
    if(bd.program(block, (1*512), sizeof(block)) != 0) {
        printf("Error\r\n");
    }

////////////////////////////////////////////////////////////////////////////////

    // Call the BD_SD_DISCO_F746NG instance de-initialisation method.
    printf("sd card deinit...\n");
    if (0 != bd.deinit()) {
        printf ("Deinit failed \n");
        return -1;
    }

    // Blink led with 2 Hz
    while(true) {
        led = !led;
        wait (0.5);
    }
}

Simple example how to use the block device to create a file on a FAT file system

/* Example file of using SD/MMC Block device Library for MBED-OS
 * Copyright 2017 Roy Krikke
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#include "mbed.h"
#include "FATFileSystem.h"
#include "SDBlockDeviceDISCOF746NG.h"
#include <stdio.h>
#include <errno.h>

DigitalOut led (LED1);

// Instantiate the Block Device for sd card on DISCO-F746NG
SDBlockDeviceDISCOF746NG bd;
FATFileSystem fs ("fs");

void
return_error (int ret_val)
{
    if(ret_val)
        printf ("Failure. %d\r\n", ret_val);
    else
        printf ("done.\r\n");
}

void
errno_error (void* ret_val)
{
    if(ret_val == NULL)
        printf (" Failure. %d \r\n", errno);
    else
        printf (" done.\r\n");
}

int
main ()
{
    Serial pc (SERIAL_TX, SERIAL_RX);
    pc.baud(115200);
    printf("Start\n");

    int error = 0;
    printf("Welcome to the filesystem example.\r\n"
           "Formatting a FAT, RAM-backed filesystem. ");
    error = FATFileSystem::format(&bd);
    return_error(error);

    printf("Mounting the filesystem on \"/fs\". ");
    error = fs.mount(&bd);
    return_error(error);

    printf("Opening a new file, numbers.txt.");
    FILE* fd = fopen("/fs/numbers.txt", "w");
    errno_error(fd);

    for (int i = 0; i < 20; i++) {
        printf("Writing decimal numbers to a file (%d/20)\r", i);
        fprintf(fd, "%d\r\n", i);
    }
    printf("Writing decimal numbers to a file (20/20) done.\r\n");

    printf("Closing file.");
    fclose(fd);
    printf(" done.\r\n");

    printf("Re-opening file read-only.");
    fd = fopen("/fs/numbers.txt", "r");
    errno_error(fd);

    printf("Dumping file to screen.\r\n");
    char buff[16] = { 0 };
    while(!feof (fd)) {
        int size = fread(&buff[0], 1, 15, fd);
        fwrite(&buff[0], 1, size, stdout);
    }
    printf("EOF.\r\n");

    printf("Closing file.");
    fclose(fd);
    printf(" done.\r\n");

    printf("Opening root directory.");
    DIR* dir = opendir("/fs/");
    errno_error(fd);

    struct dirent* de;
    printf("Printing all filenames:\r\n");
    while((de = readdir (dir)) != NULL) {
        printf("  %s\r\n", &(de->d_name)[0]);
    }

    printf("Closeing root directory. ");
    error = closedir(dir);
    return_error(error);
    printf("Filesystem Demo complete.\r\n");

    // Blink led with 2 Hz
    while(true) {
        led = !led;
        wait (0.5);
    }
}

Revisions of BSP_DISCO_F746NG.lib

Revision Date Message Actions
0:131c3e1d831e 2018-03-24 1.0.0 Release File  Diff  Annotate