/**
@page UART_TwoBoards_ComDMA UART Two Boards Communication DMA example
@verbatim
******************** (C) COPYRIGHT 2017 STMicroelectronics *******************
* @file UART/UART_TwoBoards_ComDMA/readme.txt
* @author MCD Application Team
* @brief Description of the UART Two Boards Communication DMA example.
******************************************************************************
* @attention
*
* Copyright (c) 2017 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
This example describes an UART transmission (transmit/receive) in DMA mode
between two boards.
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.
Then the SystemClock_Config() function is used to configure the system
clock (SYSCLK) to run at 180 MHz.
Then 1st board is waiting for user button key to be pressed. Once done, data
are transmitted through UART1 in DMA mode. 2nd board has configured UART1
to receive data in DMA mode. Once data received is completed, 2nd board also
transmit same characters on UART1 which will be received by 1st board.
Both boards compare transmitted data to received ones. If they are same, green
led is turn on, else red one is turn On
Warning: As both boards do not behave same way, "TRANSMITTER_BOARD" switch
compilation exists to determine either software is for 1st transmitter board or
2nd receiver (then transmitter) board. In other words, 1st board has to be
flashed with software compiled with switch enable, 2nd board has to be flashed
with software compiled with switch disable.
STM32 discovery boards LEDs can be used to monitor the transfer status:
- LED3 (green) is ON after transmission/reception callback then turn off.
It blinks at the end of example if comparison is ok
- LED4 (red) is ON when there is an error in transmission/reception process.
The UART is configured as follows:
- BaudRate = 9600 baud
- Word Length = 8 Bits (7 data bit + 1 parity bit)
- One Stop Bit
- None parity
- Hardware flow control disabled (RTS and CTS signals)
- Reception and transmission are enabled in the time
@note USARTx/UARTx instance used and associated resources can be updated in "main.h"
file depending hardware configuration used.
@note When the parity is enabled, the computed parity is inserted at the MSB
position of the transmitted data.
@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, Baud rate, RS-232, Full-duplex, DMA, Parity, Stop bit, Transmission, Reception
@par Directory contents
- UART/UART_TwoBoards_ComDMA/Inc/stm32f4xx_hal_conf.h HAL configuration file
- UART/UART_TwoBoards_ComDMA/Inc/stm32f4xx_it.h Interrupt handlers header file
- UART/UART_TwoBoards_ComDMA/Inc/main.h Main program header file
- UART/UART_TwoBoards_ComDMA/Src/stm32f4xx_it.c Interrupt handlers
- UART/UART_TwoBoards_ComDMA/Src/main.c Main program
- UART/UART_TwoBoards_ComDMA/Src/stm32f4xx_hal_msp.c HAL MSP module
- UART/UART_TwoBoards_ComDMA/Src/system_stm32f4xx.c STM32F4xx system clock configuration file
@par Hardware and Software environment
- This example runs on STM32F429xx devices.
- This example has been tested with STMicroelectronics STM32F429I-Discovery RevC
boards and can be easily tailored to any other supported device
and development board.
- STM32F429I-Discovery RevC set-up
- Connect a wire between 1st board PA09 pin (UART Tx) to 2nd board PA10 pin (UART Rx)
- Connect a wire between 1st board PA10 pin (UART Rx) to 2nd board PA09 pin (UART Tx)
@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
*/
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