/**
  @page CustomHID_Standalone USB Device Custom HID example
  
  @verbatim
  ******************************************************************************
  * @file    USB_Device/CustomHID_Standalone/readme.txt 
  * @author  MCD Application Team
  * @brief   Description of the USB Custom HID example.
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2016 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 Application Description

Use of the USB device application based on the Custom HID Class.

This is a typical example on how to use the STM32F0xx USB Device peripheral, where the STM32 MCU is 
enumerated as a HID compliant device using the native PC Host HID driver to which the STM32072B-EVAL board
is connected.

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. The user is provided with the SystemClock_Config()
function to configure the system clock (SYSCLK) to run at 48 MHz.

The 48 MHz clock for the USB can be derived from one of the two following sources:
  – PLL clock(clocked by the HSE): If the USB uses the PLL as clock source.
  – RC48 Clock (HSI48): The HSI48 clock is generated from an internal 48 MHz RC oscillator, coupled with
    the clock recovery system (CRS). 
    The CRS allows automatic trimming of the internal HSI48, synchronized with USB SOF signal at 1KHz rate, 
    to guarantee its optimal accuracy over the whole device operational range.    
User can select USB clock from HSI48 or PLL through macro defined in main.h
(USE_USB_CLKSOURCE_CRSHSI48 and USE_USB_CLKSOURCE_PLL).

@note The application needs to ensure that the SysTick time base is set to 1 millisecond
      to have correct HAL configuration.

@note To reduce the example footprint, the toolchain dynamic allocation is replaced by a static allocation
      by returning the address of a pre-defined static buffer with the HID class structure size. 
	  
@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.

To test the application, user must proceed as follows:
 - Start the "USB HID Demonstrator" PC applet and connect STM32 USB to PC
 - The device should be detected and shown in the USB HID target box
 - Press Graphic View button
 - Select "use SET_FEATURE" or "use SET_REPORT" in order to use SET_REPORT request to send HID Report
   for LED control
 - Use the potentiometer of the STM32072B-EVAL board to transfer the result of the converted voltage
  (via the ADC) the to the PC host (these values are sent to the PC using the endpoint1 IN)   
 - Make sure that following report ID are configured: LED1 ID (0x1), LED2 ID(0x2), LED3 ID(0x3),
   LED4 ID(0x4), BUTTON1_ID(0x5) and Potentiometer_ID(0x7).
 - Select LEDs to switch on/off on the STM32072B-EVAL board: a SET_REPORT request will be sent

@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

  - USB_Device/CustomHID_Standalone/Src/main.c                  Main program
  - USB_Device/CustomHID_Standalone/Src/system_stm32f0xx.c      STM32F0xx system clock configuration file
  - USB_Device/CustomHID_Standalone/Src/stm32f0xx_it.c          Interrupt handlers
  - USB_Device/CustomHID_Standalone/Src/stm32f0xx_hal_msp.c     HAL MSP module
  - USB_Device/CustomHID_Standalone/Src/usbd_conf.c             General low level driver configuration
  - USB_Device/CustomHID_Standalone/Src/usbd_desc.c             USB device descriptor
  - USB_Device/CustomHID_Standalone/Inc/main.h                  Main program header file
  - USB_Device/CustomHID_Standalone/Inc/stm32f0xx_it.h          Interrupt handlers header file
  - USB_Device/CustomHID_Standalone/Inc/stm32f0xx_hal_conf.h    HAL configuration file
  - USB_Device/CustomHID_Standalone/Inc/usbd_conf.h             USB device driver Configuration file
  - USB_Device/CustomHID_Standalone/Inc/usbd_desc.h             USB device descriptor header file

	
@par Hardware and Software environment

  - This example runs on STM32F072VB devices.

  - This example has been tested with STMicroelectronics STM32072B-EVAL RevB board and can be easily tailored 
     to any other supported device and development board.

  - STM32072B-EVAL MB1070 Rev B Set-up
    - Connect the STM32072B-EVAL board to the PC through 'USB A-Male 
      to A-Male' cable to the CN4 connector
              
@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
 

  */
