STM32CubeF0

@verbatim
******************** (C) COPYRIGHT 2016 STMicroelectronics *******************
* @file COMP/COMP_AnalogWatchdog/readme.txt
* @author MCD Application Team
* @brief Description of the Independent Watchdog Example.
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@par Example Description

How to use a pair of comparator peripherals to compare a voltage level applied on
a GPIO pin to two thresholds: the internal voltage reference (VREFINT) and a fraction
of the internal voltage reference (VREFINT/4), in interrupt mode.

- The upper threshold is set to VREFINT = 1.22V
- The lower threshold is set to VREFINT / 4 = 1.22V / 4 = 0.305V
- The input voltage is configured to be connected to PA.01

STM32 Nucleo board's LEDs can be used to monitor the transfer status:
- LED2, blinks quickly when input voltage is above the higher threshold.
- LED2, blinks slowly (once every 2 s) if the input voltage is under the lower threshold..
- If the input voltage is within the thresholds, the MCU remains in STOP mode. LED2 does not blink.

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

@par Hardware and Software environment

- This example runs on STM32F072RB devices.

- This example has been tested with STM32F072RB-Nucleo RevC board and can be
easily tailored to any other supported device and development board.

- STM32F0xx Set-up

- Use LED2,
@note This example run in stand alone mode.
- Use an external power supply and adjust supply voltage (above, within and below thresholds).

@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