/**
  @page FreeRTOS_Semaphore FreeRTOS Semaphore application
 
  @verbatim
  ******************** (C) COPYRIGHT 2017 STMicroelectronics *******************
  * @file    FreeRTOS/FreeRTOS_Semaphore/Readme.txt
  * @author  MCD Application Team
  * @brief   Description of the FreeRTOS Semaphore application.
  ******************************************************************************
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  *
  * <h2><center>&copy; Copyright © 2017 STMicroelectronics International N.V. 
  * All rights reserved.</center></h2>
  *
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  ******************************************************************************
  @endverbatim

@par Description

This directory contains a set of source files that implement an application that
uses semaphores with CMSIS RTOS API 

This application creates two threads that toggle LEDs through a shared semaphore.

The first thread which have the higher priority obtains the semaphore and 
toggle the LED1 each 200 ms. After 5 seconds it releases the semaphore and 
suspends itself. 

The low priority thread can execute now, it obtains the 
semaphore and resume execution of the first thread, as it has the higher 
priority the first thread will try to obtain the semaphore but it fails 
because the semaphore is already taken by the low 
priority thread, which will toggle the LED2 for 5 seconds before releasing 
the semaphore and begin a new cycle.


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

@note The FreeRTOS heap size configTOTAL_HEAP_SIZE defined in FreeRTOSConfig.h is set 
      according to the OS resources memory requirements of the application with +10% margin and 
      rounded to the upper Kbyte boundary.

For more details about FreeRTOS implementation on STM32Cube, please refer to UM1722 "Developing Applications 
on STM32Cube with RTOS".


@par Directory contents

    - FreeRTOS/FreeRTOS_Semaphore/Inc/main.h                Main program header file
    - FreeRTOS/FreeRTOS_Semaphore/Inc/stm32f2xx_hal_conf.h  HAL Library Configuration file
    - FreeRTOS/FreeRTOS_Semaphore/Inc/stm32f2xx_it.h        Interrupt handlers header file
    - FreeRTOS/FreeRTOS_Semaphore/Inc/FreeRTOSConfig.h      FreeRTOS Configuration file
    - FreeRTOS/FreeRTOS_Semaphore/Src/main.c                Main program
    - FreeRTOS/FreeRTOS_Semaphore/Src/stm32f2xx_it.c        Interrupt handlers


@par Hardware and Software environment

  - This application runs on STM32F2xx devices.
    
  - This application has been tested with STM322xG-EVAL evaluation 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 application

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