/**
@page COMP_AnalogWatchdog Independent Watchdog Example
@verbatim
******************** (C) COPYRIGHT 2016 STMicroelectronics *******************
* @file COMP/COMP_AnalogWatchdog/readme.txt
* @author MCD Application Team
* @brief Description of the Independent Watchdog 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 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:
In case of 4 or 8 LEDS available:
- $LED3$ and LED2 are turned On, if the input voltage is above the higher threshold.
- $LED2$ and $LED4$ are turned On, if the input voltage is under the lower threshold.
In case of 1 LED available:
- 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 STM32F091RC-Nucleo RevC devices.
- This example has been tested with STM32F091RC-Nucleo RevC board and can be
easily tailored to any other supported device and development board.
- STM32F0xx Set-up
- Use LED2 connected to PA.05
@note This example run in stand alone mode.
- Use a wire to connect Potentiometer RV3 (PC.00 pin, connected to pin38 on CN7) to COMP2 non inverting input (PA.01, connected to pin 30 on CN7)
Alternatively 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
*/
a58188598c