STM32CubeF4

/**
  @page RTC_TimeStamp RTC time stamp Example

  @verbatim
  ******************** (C) COPYRIGHT 2017 STMicroelectronics *******************
  * @file    RTC/RTC_TimeStamp/readme.txt
  * @author  MCD Application Team
  * @brief   Description of the RTC time stamp example.
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2017 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
   @endverbatim

@par Example Description

This example guides you through the different configuration steps by means of the RTC
HAL API to demonstrate the timestamp feature.

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 100 MHz.

The RTC peripheral configuration is ensured by the HAL_RTC_Init() function.
This later is calling the HAL_RTC_MspInit()function which core is implementing
the configuration of the needed RTC resources according to the used hardware (CLOCK,
PWR, RTC clock source and BackUp). You may update this function to change RTC configuration.

@note LSE oscillator clock is used as RTC clock source by default.
      The user can use also LSI as RTC clock source. The user uncomment the adequate
      line on the main.h file.
      @code
        #define RTC_CLOCK_SOURCE_LSE
        /* #define RTC_CLOCK_SOURCE_LSI */
      @endcode
      LSI oscillator clock is delivered by a 32 kHz RC.
      LSE (when available on board) is delivered by a 32.768 kHz crystal.

HAL_RTCEx_SetTimeStamp_IT()function is then called to initialize the time stamp feature
with interrupt mode. It configures the time stamp pin to be rising edge and enables
the time stamp detection on time stamp pin.
HAL_RTC_SetTime()and HAL_RTC_SetDate() functions are then called to initialize the
time and the date.

The associated firmware performs the following:
1. After startup the program configure the RTC (Time date) and enable the feature
   timeStamp.

2. When applying a high level on the time stamp pin PC.13 (Connecting pin D7 on CN8 Connector to 3V3 pin),
   a time stamp event is detected and the calendar is saved in the time stamp structures.
   Each time the user apply a high level on the PC.13 pin, the current time and time stamp are updated and displayed
   on the debugger in aShowTime and aShowTimeStamp variables .


- LED4 is toggling : This indicates that the system generates an error.

@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 Keywords

RTC, Timer, Timestamp, Counter, LSE, LSI, Current time, Real Time Clock

@par Directory contents

  - RTC/RTC_TimeStamp/Inc/stm32f4xx_hal_conf.h    HAL configuration file
  - RTC/RTC_TimeStamp/Inc/stm32f4xx_it.h          Interrupt handlers header file
  - RTC/RTC_TimeStamp/Inc/main.h                  Header for main.c module
  - RTC/RTC_TimeStamp/Src/stm32f4xx_it.c          Interrupt handlers
  - RTC/RTC_TimeStamp/Src/main.c                  Main program
  - RTC/RTC_TimeStamp/Src/stm32f4xx_hal_msp.c     HAL MSP module
  - RTC/RTC_TimeStamp/Src/system_stm32f4xx.c      STM32F4xx system source file


@par Hardware and Software environment

  - This example runs on STM32F413xx devices.
  - This example has been tested with STMicroelectronics STM32F413H-DISCOVERY
    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



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