/**
  @page ADC_RegularConversion_Interrupt conversion using interrupt

  @verbatim
  ******************** (C) COPYRIGHT 2017 STMicroelectronics *******************
  * @file    ADC/ADC_RegularConversion_Interrupt/readme.txt 
  * @author  MCD Application Team
  * @brief   Description of the ADC RegularConversion interrupt example.
  ******************************************************************************
  *
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  *   3. Neither the name of STMicroelectronics nor the names of its contributors
  *      may be used to endorse or promote products derived from this software
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  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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  ******************************************************************************
  @endverbatim

@par Example Description 

This example describes how to use the ADC in interrupt mode to convert data through the HAL API.

The ADC1 is configured to convert continuously ADC_CHANNEL_7.

Each time an end of conversion occurs an interrupt is generated and the converted 
data of ADC3 DR register is affected to the uhADCxConvertedValue variable in the 
ADC conversion complete call back function.

The uhADCxConvertedValue read value is coded on 12 bits, the Vref+ reference voltage is connected 
on the board to VDD (+3.3V), the Vref- reference voltage is connected on the board to the ground.
To convert the read value in volts, here is the equation to apply :
Voltage = uhADCxConvertedValue * (Vref+ - Vref-) / (2^12) = uhADCxConvertedValue * 3.3 / 4096

In this example, the system clock is 120MHz, APB2 = 60MHz and ADC clock = APB2/2. 
Since ADC3 clock is 30 MHz and sampling time is set to 3 cycles, the conversion 
time to 12bit data is 12 cycles so the total conversion time is (12+3)/30= 0.5us(2Msps).

User can vary the ADC_CHANNEL_7 voltage by applying an input voltage on pin PF.09
(e.g. using function generator).

The converted value is monitored through debugger: uhADCxConvertedValue variable.

STM32 Nucleo board's LEDs can be used to monitor the transfer status:
  - LED3 is ON when there are an error in initialization.

@par Directory contents 

  - ADC/ADC_RegularConversion_Interrupt/Inc/stm32f2xx_hal_conf.h    HAL configuration file
  - ADC/ADC_RegularConversion_Interrupt/Inc/stm32f2xx_it.h          DMA interrupt handlers header file
  - ADC/ADC_RegularConversion_Interrupt/Inc/main.h                  Header for main.c module  
  - ADC/ADC_RegularConversion_Interrupt/Src/stm32f2xx_it.c          DMA interrupt handlers
  - ADC/ADC_RegularConversion_Interrupt/Src/main.c                  Main program
  - ADC/ADC_RegularConversion_Interrupt/Src/stm32f2xx_hal_msp.c     HAL MSP file 
  - ADC/ADC_RegularConversion_Interrupt/Src/system_stm32f2xx.c      STM32F2xx system source file

@par Hardware and Software environment 

  - This example runs on STM32F207xx devices.
  
  - This example has been tested with NUCLEO-207ZG 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>
 */
