/**
@page USART_WakeUpFromStop_Init USART example
@verbatim
******************************************************************************
* @file Examples_LL/USART/USART_WakeUpFromStop_Init/readme.txt
* @author MCD Application Team
* @brief Description of the USART_WakeUpFromStop_Init USART example.
******************************************************************************
*
* Copyright (c) 2020 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
Configuration of GPIO and USART1 peripherals to allow the characters received on USART_RX pin to wake up the MCU from low-power mode.
This example is based on the STM32WLxx USART1 LL API. The peripheral
initialization uses LL unitary service functions for optimization purposes (performance and size).
USART1 Peripheral is configured in asynchronous mode (9600 bauds, 8 data bit, 1 start bit, 1 stop bit, no parity).
No HW flow control is used.
USART1 Clock is based on HSI.
Example execution:
After startup from reset and system configuration, LED2 is blinking quickly during 3 sec,
then MCU enters "Stop 0" mode (LED2 off).
On first character reception by the USART1 from PC Com port (ex: using HyperTerminal)
after "Stop 0" Mode period, MCU wakes up from "Stop 0" Mode.
Received character value is checked :
- On a specific value ('S' or 's'), LED2 is turned On and program ends.
- If different from 'S' or 's', program performs a quick LED2 blinks during 3 sec and
enters again "Stop 0" mode, waiting for next character to wake up.
In case of errors, LED2 is slowly blinking (1 sec period).
@par Keywords
Connectivity, UART/USART, Asynchronous, RS-232, baud rate, Interrupt, HyperTerminal,
Receiver, Asynchronous, Low Power, Wake Up
@par Directory contents
- USART/USART_WakeUpFromStop_Init/Inc/stm32wlxx_it.h Interrupt handlers header file
- USART/USART_WakeUpFromStop_Init/Inc/main.h Header for main.c module
- USART/USART_WakeUpFromStop_Init/Inc/stm32_assert.h Template file to include assert_failed function
- USART/USART_WakeUpFromStop_Init/Src/stm32wlxx_it.c Interrupt handlers
- USART/USART_WakeUpFromStop_Init/Src/main.c Main program
- USART/USART_WakeUpFromStop_Init/Src/system_stm32wlxx.c STM32WLxx system source file
@par Hardware and Software environment
- This example runs on STM32WL55JCIx devices.
- This example has been tested with NUCLEO-WL55JC RevC board and can be
easily tailored to any other supported device and development board.
- NUCLEO-WL55JC RevC Set-up
- Connect STM32 MCU board USART1 TX pin (GPIO PA9 connected to pin 19 of Arduino connector CN10)
to PC COM port RX signal
- Connect STM32 MCU board USART1 RX pin (GPIO PA10 connected to pin 32 of Arduino connector CN7)
to PC COM port TX signal
- Connect STM32 MCU board GND to PC COM port GND signal
- Launch serial communication SW on PC (as HyperTerminal or TeraTerm) with proper configuration
(9600 bauds, 8 bits data, 1 stop bit, no parity, no HW flow control).
@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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