/**
  @page FatFs_uSD   FatFs with uSD card drive example
 
  @verbatim
  ******************** (C) COPYRIGHT 2016 STMicroelectronics *******************
  * @file    readme.txt
  * @author  MCD Application Team
  * @version V1.6.0
  * @date    12-May-2017
  * @brief   Description of the FatFs with uSD card drive example
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright © 2016 STMicroelectronics International N.V. 
  * All rights reserved.</center></h2>
  *
  * Redistribution and use in source and binary forms, with or without 
  * modification, are permitted, provided that the following conditions are met:
  *
  * 1. Redistribution of source code must retain the above copyright notice, 
  *    this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright notice,
  *    this list of conditions and the following disclaimer in the documentation
  *    and/or other materials provided with the distribution.
  * 3. Neither the name of STMicroelectronics nor the names of other 
  *    contributors to this software may be used to endorse or promote products 
  *    derived from this software without specific written permission.
  * 4. This software, including modifications and/or derivative works of this 
  *    software, must execute solely and exclusively on microcontroller or
  *    microprocessor devices manufactured by or for STMicroelectronics.
  * 5. Redistribution and use of this software other than as permitted under 
  *    this license is void and will automatically terminate your rights under 
  *    this license. 
  *
  * THIS SOFTWARE IS PROVIDED BY STMICROELECTRONICS AND CONTRIBUTORS "AS IS" 
  * AND ANY EXPRESS, IMPLIED OR STATUTORY WARRANTIES, INCLUDING, BUT NOT 
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A 
  * PARTICULAR PURPOSE AND NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY
  * RIGHTS ARE DISCLAIMED TO THE FULLEST EXTENT PERMITTED BY LAW. IN NO EVENT 
  * SHALL STMICROELECTRONICS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 
  * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 
  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 
  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
  * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  ******************************************************************************
  @endverbatim

@par Example Description

This example provides a description on how to use STM32Cube firmware with FatFs 
middleware component as a generic FAT file system module. The objective is to 
develop an application using most of the features offered by FatFs to 
configure a microSD drive.

At the beginning of the main program the HAL_Init() function is called to reset 
all the peripherals, initialize the Flash interface and the systick.
Then the SystemClock_Config() function is used to configure the system clock
(SYSCLK) to run at 72 MHz.
 
The application is based on writing and reading back a text file from a drive,
and it's performed using FatFs APIs to access the FAT volume as described
in the following steps: 

 - Link the uSD disk I/O driver;
 - Register the file system object (mount) to the FatFs module for the uSD drive;
 - Create a FAT file system (format) on the uSD drive;
 - Create and Open new text file object with write access;
 - Write data to the text file;
 - Close the open text file;
 - Open text file object with read access;
 - Read back data from the text file;
 - Close the open text file;
 - Check on read data from text file;
 - Unlink the uSD disk I/O driver.

It is worth noting that the application manages any error occurred during the 
access to FAT volume, when using FatFs APIs. Otherwise, user can check if the
written text file is available on the uSD card.

It is possible to fine tune needed FatFs features by modifying defines values 
in FatFs configuration file “ffconf.h” available under the project includes 
directory, in a way to fit the application requirements. 

STM3210E-EVAL RevD's LEDs can be used to monitor the example status:
  - LED_GREEN is on when the example runs successfully.
  - LED_RED is blinking in case of error in initialization or during FatFs_uSD process.

@note Care must be taken when using HAL_Delay(), this function provides accurate delay (in milliseconds)
      based on variable incremented in SysTick ISR. This implies that if HAL_Delay() is called from
      a peripheral ISR process, then the SysTick interrupt must have higher priority (numerically lower)
      than the peripheral interrupt. Otherwise the caller ISR process will be blocked.
      To change the SysTick interrupt priority you have to use HAL_NVIC_SetPriority() function.
      
@note The application need to ensure that the SysTick time base is always set to 1 millisecond
      to have correct HAL operation.

@par Directory contents
 
  - FatFs/FatFs_uSD/Inc/stm32f1xx_hal_conf.h    HAL configuration file
  - FatFs/FatFs_uSD/Inc/stm32f1xx_it.h          Interrupt handlers header file
  - FatFs/FatFs_uSD/Inc/main.h                  Header for main.c module
  - FatFs/FatFs_uSD/Inc/ffconf.h                FAT file system module configuration file   
  - FatFs/FatFs_uSD/Src/stm32f1xx_it.c          Interrupt handlers
  - FatFs/FatFs_uSD/Src/main.c                  Main program
  - FatFs/FatFs_uSD/Src/system_stm32f1xx.c      STM32F1xx system source file

@par Hardware and Software environment

  - This example runs on STM32F103xG devices
    
  - This example has been tested with STM3210E-EVAL RevD board and can be
    easily tailored to any other supported device and development board.        

@par How to use it ? 

In order to make the program work, you must do the following:
 - Open your preferred toolchain 
 - Rebuild all files and load your image into target memory
 - Run the example

 * <h3><center>&copy; COPYRIGHT STMicroelectronics</center></h3>
 */
