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100 lines
5.0 KiB
Plaintext
100 lines
5.0 KiB
Plaintext
/**
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@page COMP_AnalogWatchdog Independent Watchdog Example
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@verbatim
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******************** (C) COPYRIGHT 2016 STMicroelectronics *******************
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* @file COMP/COMP_AnalogWatchdog/readme.txt
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* @author MCD Application Team
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* @brief Description of the Independent Watchdog Example.
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******************************************************************************
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*
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* Redistribution and use in source and binary forms, with or without modification,
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* are permitted provided that the following conditions are met:
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* 1. Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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* 3. Neither the name of STMicroelectronics nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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******************************************************************************
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@endverbatim
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@par Example Description
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How to use a pair of comparator peripherals to compare a voltage level applied on
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a GPIO pin to two thresholds: the internal voltage reference (VREFINT) and a fraction
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of the internal voltage reference (VREFINT/4), in interrupt mode.
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- The upper threshold is set to VREFINT = 1.22V
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- The lower threshold is set to VREFINT / 4 = 1.22V / 4 = 0.305V
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- The input voltage is configured to be connected to PA.01
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STM32 Eval board's LEDs can be used to monitor the transfer status:
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In case of 4 or 8 LEDS available:
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- LED3 and LED1 are turned On, if the input voltage is above the higher threshold.
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- LED2 and LED4 are turned On, if the input voltage is under the lower threshold.
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In case of 1 LED available:
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- LED1, blinks quickly when input voltage is above the higher threshold.
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- LED1, blinks slowly (once every 2 s) if the input voltage is under the lower threshold..
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- If the input voltage is within the thresholds, the MCU remains in STOP mode. LED1 does not blink.
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@note Care must be taken when using HAL_Delay(), this function provides
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accurate delay (in milliseconds) based on variable incremented in SysTick ISR.
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This implies that if HAL_Delay() is called from a peripheral ISR process, then
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the SysTick interrupt must have higher priority (numerically lower) than the
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peripheral interrupt. Otherwise the caller ISR process will be blocked.
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To change the SysTick interrupt priority you have to use HAL_NVIC_SetPriority() function.
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@note The application need to ensure that the SysTick time base is always set
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to 1 millisecond to have correct HAL operation.
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@par Directory contents
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- COMP/COMP_AnalogWatchdog/Inc/stm32f0xx_hal_conf.h HAL configuration file
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- COMP/COMP_AnalogWatchdog/Inc/stm32f0xx_it.h COMP interrupt handlers header file
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- COMP/COMP_AnalogWatchdog/Inc/main.h Header for main.c module
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- COMP/COMP_AnalogWatchdog/Src/stm32f0xx_it.c COMP interrupt handlers
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- COMP/COMP_AnalogWatchdog/Src/main.c Main program
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- COMP/COMP_AnalogWatchdog/Src/stm32f0xx_hal_msp.c HAL MSP file
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- COMP/COMP_AnalogWatchdog/Src/system_stm32f0xx.c STM32F0xx system source file
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@par Hardware and Software environment
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- This example runs on STM32091C-EVAL devices.
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- This example has been tested with STM32091C-EVAL board and can be
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easily tailored to any other supported device and development board.
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- STM32F0xx Set-up
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- Use LED1, LED2, LED3 and LED4 connected respectively to PE.00, PE.01 ,PE.07
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and PE.08 pins
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@note This example run in stand alone mode.
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- Use a wire to connect Potentiometer RV3 (PC.00 pin) to COMP2 non inverting input (PA.01)
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Alternatively use an external power supply and adjust supply voltage (above, within and below thresholds).
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@par How to use it ?
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In order to make the program work, you must do the following :
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- Open your preferred toolchain
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- Rebuild all files and load your image into target memory
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- Run the example
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* <h3><center>© COPYRIGHT STMicroelectronics</center></h3>
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*/
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