127 lines
6.1 KiB
Plaintext
127 lines
6.1 KiB
Plaintext
/**
|
|
@page USART_SlaveMode USART Slave Mode example
|
|
|
|
@verbatim
|
|
******************************************************************************
|
|
* @file USART/USART_SlaveMode/readme.txt
|
|
* @author MCD Application Team
|
|
* @brief Description of the USART_SlaveMode 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
|
|
|
|
This example describes an USART-SPI communication (transmit/receive) between two
|
|
boards where the USART is configured as a slave.
|
|
|
|
Boards: NUCLEO-WL55JC RevC (embeds a STM32WL55JCIx device)
|
|
|
|
_________________________ _________________________
|
|
| _______________| |_______________ |
|
|
| | SPI1 | | USART1 | |
|
|
| | | | | |
|
|
| | PB3 (CN9.4)|SCK_________________CK|(CN9.5) PB5 | |
|
|
| | | | | |
|
|
| | PA11 (CN5.9)|MISO________________TX|(CN9.2) PB6 | |
|
|
| | | | | |
|
|
| | PA12 (CN5.10)|MOSI________________RX|(CN9.1) PB7 | |
|
|
| | | | | |
|
|
| |_______________| |_______________| |
|
|
| __ | | |
|
|
| |__| | | |
|
|
| USER | | |
|
|
| GND|______________________|GND |
|
|
| | | |
|
|
|_STM32WLxx_Master________| |_STM32WLxx_Slave_________|
|
|
|
|
|
|
Two identical boards are connected as shown on the picture above.
|
|
Board 1: SPI Master board
|
|
Board 2: USART Slave board
|
|
|
|
In a first step, after the user presses the User push-button, Master (SPI) starts
|
|
the communication by sending aTxBuffer and receiving aRxBuffer through
|
|
HAL_SPI_TransmitReceive(), at the same time Slave (USART) transmits aTxBuffer
|
|
and receives aRxBuffer through HAL_USART_TransmitReceive().
|
|
Finally, aRxBuffer and aTxBuffer are compared through Buffercmp() in order to
|
|
check buffers correctness.
|
|
|
|
WARNING: as both boards do not behave the same way, "SLAVE_BOARD" compilation
|
|
switch is defined in Src/main.c and must be enabled at compilation time before
|
|
loading the executable in the USART slave board.
|
|
The SPI master board needs to be loaded with an executable software obtained
|
|
with SLAVE_BOARD disabled.
|
|
|
|
NUCLEO-WL55JC RevC board LEDs are used to monitor the transfer status:
|
|
- While board 1 is waiting for the user to press the User push-button, its
|
|
LED1 is blinking rapidly (100 ms period).
|
|
- After the transmission/reception processes begin LED1 is turned off.
|
|
- When the test passes, LED1 on both boards is turned on, otherwise the
|
|
test has failed.
|
|
- If there is an initialization or transfer error, LED3 blinks slowly (500 ms).
|
|
|
|
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 STM32WL55JCIx Devices.
|
|
|
|
@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 needs to ensure that the SysTick time base is always set to
|
|
1 millisecond to have correct HAL operation.
|
|
|
|
@par Keywords
|
|
|
|
Connectivity, UART/USART, SPI interface, full-duplex, Polling, Receiver, Transmitter, Synchronous, Slave,
|
|
|
|
@par Directory contents
|
|
|
|
- USART/USART_SlaveMode/Inc/stm32wlxx_nucleo_conf.h BSP configuration file
|
|
- USART/USART_SlaveMode/Src/main.c Main program
|
|
- USART/USART_SlaveMode/Src/system_stm32wlxx.c STM32WLxx system clock configuration file
|
|
- USART/USART_SlaveMode/Src/stm32wlxx_it.c Interrupt handlers
|
|
- USART/USART_SlaveMode/Src/stm32wlxx_hal_msp.c HAL MSP module
|
|
- USART/USART_SlaveMode/Inc/main.h Main program header file
|
|
- USART/USART_SlaveMode/Inc/stm32wlxx_hal_conf.h HAL Configuration file
|
|
- USART/USART_SlaveMode/Inc/stm32wlxx_it.h Interrupt handlers header file
|
|
|
|
|
|
@par Hardware and Software environment
|
|
|
|
- This example runs on STM32WL55JCIx devices.
|
|
|
|
- This example has been tested with two NUCLEO-WL55JC RevC boards embedding
|
|
a STM32WL55JCIx device and can be easily tailored to any other supported device
|
|
and development board.
|
|
|
|
- NUCLEO-WL55JC RevC set-up
|
|
- Connect Master board PB3 (SCK) to Slave Board PB5 (USART CK)
|
|
- Connect Master board PA11 (MISO) to Slave Board PB6 (USART TX)
|
|
- Connect Master board PA12 (MOSI) to Slave Board PB7 (USART RX)
|
|
- Connect Master board GND to Slave Board GND
|
|
|
|
@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
|
|
- Uncomment "#define SLAVE_BOARD" and load the project in Slave Board
|
|
- Comment "#define SLAVE_BOARD" and load the project in Master Board
|
|
- Run the example
|
|
|
|
* <h3><center>© COPYRIGHT STMicroelectronics</center></h3>
|
|
*/
|