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diff --git a/Projects/NUCLEO-WB35CE/Examples/COMP/COMP_CompareGpioVsVrefInt_IT/readme.txt b/Projects/NUCLEO-WB35CE/Examples/COMP/COMP_CompareGpioVsVrefInt_IT/readme.txt new file mode 100644 index 000000000..51266e3e8 --- /dev/null +++ b/Projects/NUCLEO-WB35CE/Examples/COMP/COMP_CompareGpioVsVrefInt_IT/readme.txt @@ -0,0 +1,87 @@ +/** + @page COMP_CompareGpioVsVrefInt_IT COMP example + + @verbatim + ****************************************************************************** + * @file Examples/COMP/COMP_CompareGpioVsVrefInt_IT/readme.txt + * @author MCD Application Team + * @brief Description of the COMP_CompareGpioVsVrefInt_IT Example. + ****************************************************************************** + * + * Copyright (c) 2019 STMicroelectronics. All rights reserved. + * + * This software component is licensed by ST under BSD 3-Clause license, + * the "License"; You may not use this file except in compliance with the + * License. You may obtain a copy of the License at: + * opensource.org/licenses/BSD-3-Clause + * + ****************************************************************************** + @endverbatim + +@par Example Description + +How to configure the COMP peripheral to compare the external +voltage applied on a specific pin with the Internal Voltage Reference. + +At the beginning of the main program the HAL_Init() function is called to reset +all the peripherals, initialize the Flash interface and the systick. + +The SystemClock_Config() function is used to configure the system clock for STM32WB35CEUx Devices + +When the comparator input crosses (either rising or falling edges) the internal +reference voltage VREFINT (1.22V), the comparator generates an interrupt +and exit from STOP mode. + +The System enters STOP mode 5 seconds after the comparator is started and +after any system wake-up triggered by the comparator interrupt. + +In this example, the comparator input is connected on the pin PA1 (Arduino connector CN8 pin A2, Morpho connector CN7 pin 32). +The user shall apply a voltage on and each time the comparator input crosses VREFINT, MCU is awake, +system clock is reconfigured and LED2 is ON. + +If LED3 is toggling continuously without any voltage update, it indicates that the system +generated 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 Keywords + +comparator, stop mode, voltage compare, wakeup trigger, comparator interrupt. + +@par Directory contents + + - COMP/COMP_CompareGpioVsVrefInt_IT/Inc/stm32wbxx_hal_conf.h HAL configuration file + - COMP/COMP_CompareGpioVsVrefInt_IT/Inc/stm32wbxx_it.h COMP interrupt handlers header file + - COMP/COMP_CompareGpioVsVrefInt_IT/Inc/main.h Header for main.c module + - COMP/COMP_CompareGpioVsVrefInt_IT/Src/stm32wbxx_it.c COMP interrupt handlers + - COMP/COMP_CompareGpioVsVrefInt_IT/Src/main.c Main program + - COMP/COMP_CompareGpioVsVrefInt_IT/Src/stm32wbxx_hal_msp.c HAL MSP file + - COMP/COMP_CompareGpioVsVrefInt_IT/Src/system_stm32wbxx.c STM32WBxx system source file + + +@par Hardware and Software environment + + - This example runs on STM32WB35xx devices. + + - This example has been tested with NUCLEO-WB35CE board and can be + easily tailored to any other supported device and development board. + + - Apply an external variable voltage on PA1 (Arduino connector CN8 pin A2, Morpho connector CN7 pin 32) 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 + + * <h3><center>© COPYRIGHT STMicroelectronics</center></h3> + */
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