Issue in Read and Write using SD_Card.

[vbk22398]

The issue is that I am able to create a bin file, write data into the SD-Card properly. But when I read data, it is not proper, and the data is corrupted. It worked well previously but the same code is not working now. Could you please check where I am wrong. I am using STM32L496ZGT6. I am using a Micro SD Card adapter.

WRITING FUNCTION

void push_to_stack(data *newData) {

      fres = f_mount(&fs, "", 0);

if (fres == FR_OK) {

transmit_uart("Micro SD card is mounted successfully for writing!\n");

} else if (fres != FR_OK) {

transmit_uart("Micro SD card's mount error!\n");

}

      fres = f_open(&fil, "log-file.bin",  FA_WRITE| FA_OPEN_ALWAYS  );

if (fres != FR_OK) {

transmit_uart("Failed to open file for writing.\n");

f_mount(NULL, "", 1);  // Unmount before returning

}

fres = f_lseek(&fil, f_size(&fil));

    if (fres != FR_OK) {

        transmit_uart("Error seeking to the end of the file.\n");

        f_close(&fil);  // Close the file if seek fails

        f_mount(NULL, "", 1);  // Unmount before returning

        return;

    }

    // Write the structure to the file

    fres = f_write(&fil, newData, sizeof(data), &bytesWritten);

    if (fres == FR_OK && bytesWritten == sizeof(data)) {

        transmit_uart("Data successfully written to stack.\n");

    } else {

        transmit_uart("Error writing data to stack.\n");

    }

    fres = f_close(&fil);

    if (fres == FR_OK) {

    transmit_uart("The file is closed.\n");

    } else if (fres != FR_OK) {

    transmit_uart("The file was not closed.\n");

    }

    f_mount(NULL, "",1);

}

READ FUNCTION

void read_from_stack_and_send(uint32_t index) {

    // Mount the file system

    fres = f_mount(&fs, "", 0);

    if (fres != FR_OK) {

        transmit_uart("Failed to mount SD card.\n");

        return;

    } else {

        transmit_uart("SD card mounted successfully for reading.\n");

    }

    // Open file in read mode

    fres = f_open(&fil, "log-file.bin", FA_READ);

    if (fres != FR_OK) {

        transmit_uart("Failed to open file for reading.\n");

        return;

    } else {

        transmit_uart("File opened for reading successfully.\n");

    }

    fres = f_lseek(&fil,index * sizeof(data));

    if(fres != FR_OK){

    transmit_uart("Error reading data from file.\n");

    f_close(&fil);  // Close the file if seek fails

    f_mount(NULL, "", 1);  // Unmount before returning

    }

    // Read data sequentially

    data readData;

    UINT bytesRead;

   // while (1) {

        // Read a single `data` structure from the file

    memset(&readData, 0, sizeof(data));

        fres = f_read(&fil, &readData, sizeof(data), &bytesRead);

        if (fres != FR_OK) {

            transmit_uart("Error reading data from file.\n");

        }

        // Check if end of file reached

        if (bytesRead == 0) {

            transmit_uart("End of file reached.\n");

        }

        // Print the read data

        char msg[100];

        sprintf(msg, "ID: %d, Value: %d, Name: %s\n", readData.ID, readData.value, readData.ename);

        transmit_uart(msg);

  //  }

    // Close the file

    fres = f_close(&fil);

    if (fres != FR_OK) {

        transmit_uart("Failed to close the file.\n");

    } else {

        transmit_uart("File closed successfully.\n");

    }

    // Unmount the file system

    fres = f_mount(NULL, "", 1);

    if (fres != FR_OK) {

        transmit_uart("Failed to unmount SD card.\n");

    } else {

        transmit_uart("SD card unmounted successfully.\n");

    }

}

MAIN FUNCTION

    memset(buffer,0,sizeof(buffer));

    HAL_UART_Receive(&huart3, (uint8_t *)buffer, 100, 100);

    buffer[100]='\0';

    if(sscanf((char *)buffer,"UPDATE:%d,%d,%s",&cmdType,&value,name)==3){

    data received = {cmdType,value};

    strncpy(received.ename,name,sizeof(received.ename)-1);

    received.ename[sizeof(received.ename)-1]='\0';

    push_to_stack(&received);

    }

    else if(sscanf((char *)buffer,"INDEX:%d",&Index)==1){

    uint8_t buf[sizeof(data)];

    read_from_stack_and_send(Index);

    }