STM32CubeF0

@verbatim
******************** (C) COPYRIGHT 2016 STMicroelectronics *******************
* @file COMP/COMP_Interrupt/readme.txt
* @author MCD Application Team
* @brief Description of the COMP Interrupt example.
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@endverbatim

@par Example Description

How to use a comparator peripheral to compare a voltage level applied on a GPIO
pin to the the internal voltage reference (VREFINT), in interrupt mode.

When the comparator input crosses (either rising or falling edges) the internal reference
voltage VREFINT (1.22V), the comparator generates an interrupt.

In this example, the comparator is connected on pin PA1.
Each time comparator input crosses VREFINT, LED1 toggles.

If LED2 is powering on: 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 Directory contents

- COMP/COMP_Interrupt/Inc/stm32f0xx_hal_conf.h HAL configuration file
- COMP/COMP_Interrupt/Inc/stm32f0xx_it.h Interrupt handlers header file
- COMP/COMP_Interrupt/Inc/main.h Header for main.c module
- COMP/COMP_Interrupt/Src/stm32f0xx_it.c Interrupt handlers
- COMP/COMP_Interrupt/Src/main.c Main program
- COMP/COMP_Interrupt/Src/stm32f0xx_hal_msp.c HAL MSP file
- COMP/COMP_Interrupt/Src/system_stm32f0xx.c STM32F0xx system source file

@par Hardware and Software environment

- This example runs on STM32F091xC devices.

- This example has been tested with STM32F091RC-Nucleo RevC board and can be
easily tailored to any other supported device and development board.

- STM32F091RC-Nucleo RevC Set-up

- Use LED2 connected to PA.05 pin
- Apply an external variable voltage on PA1(connected to pin 30 on CN7) with average voltage 1.22V.

@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