STM32怎么使用DMA将串口接收到的数据压入缓冲区？

Question

之前看了一些人的程序，没有使用RTOS的，他们每次都是在中断中把数据压入缓冲区，我在想DMA能不能把数据压入缓冲区呢？

这样既可以不过多占用CPU系统资源的同时又能压入缓冲区，然后在其他线程进行处理。

希望能知道怎么实现DMA把数据压入缓冲区？

（或者怎么调用DMA的接收完成中断~~）

Answer 1

bsp包里有UART&DMA的范例，用的是HAL库，你看看

/**
  ******************************************************************************
  * @file    UART/UART_TwoBoards_ComDMA/Src/main.c 
  * @author  MCD Application Team
  * @brief   This sample code shows how to use UART HAL API to transmit
  *          and receive a data buffer with a communication process based on
  *          DMA transfer. 
  *          The communication is done using 2 Boards.
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; COPYRIGHT(c) 2016 STMicroelectronics</center></h2>
  *
  * Redistribution and use in source and binary forms, with or without modification,
  * are permitted provided that the following conditions are met:
  *   1. Redistributions of source code must retain the above copyright notice,
  *      this list of conditions and the following disclaimer.
  *   2. Redistributions in binary form must reproduce the above copyright notice,
  *      this list of conditions and the following disclaimer in the documentation
  *      and/or other materials provided with the distribution.
  *   3. Neither the name of STMicroelectronics nor the names of its contributors
  *      may be used to endorse or promote products derived from this software
  *      without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  ******************************************************************************
  */

/* Includes ------------------------------------------------------------------*/
#include "main.h"

/** @addtogroup STM32F0xx_HAL_Examples
  * @{
  */

/** @addtogroup UART_TwoBoards_ComDMA
  * @{
  */ 

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
#define TRANSMITTER_BOARD

/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* UART handler declaration */
UART_HandleTypeDef UartHandle;
__IO ITStatus UartReady = RESET;
__IO uint32_t UserButtonStatus = 0;  /* set to 1 after User Button interrupt  */

/* Buffer used for transmission */
uint8_t aTxBuffer[] = " ****UART_TwoBoards communication based on DMA****  ****UART_TwoBoards communication based on DMA****  ****UART_TwoBoards communication based on DMA**** ";

/* Buffer used for reception */
uint8_t aRxBuffer[RXBUFFERSIZE];

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void Error_Handler(void);
static uint16_t Buffercmp(uint8_t* pBuffer1, uint8_t* pBuffer2, uint16_t BufferLength);

/* Private functions ---------------------------------------------------------*/

/**
  * @brief  Main program
  * @param  None
  * @retval None
  */
int main(void)
{
  /* STM32F0xx HAL library initialization:
       - Configure the Flash prefetch
       - Systick timer is configured by default as source of time base, but user 
         can eventually implement his proper time base source (a general purpose 
         timer for example or other time source), keeping in mind that Time base 
         duration should be kept 1ms since PPP_TIMEOUT_VALUEs are defined and 
         handled in milliseconds basis.
       - Low Level Initialization
     */
  HAL_Init();

  /* Configure the system clock to 48 MHz */
  SystemClock_Config();
  
  /* Configure LED3 and LED4 */
  BSP_LED_Init(LED3);
  BSP_LED_Init(LED4);

#ifdef TRANSMITTER_BOARD
  /* Configure User push-button in Interrupt mode */
  BSP_PB_Init(BUTTON_USER, BUTTON_MODE_EXTI);
  
  /* Wait for User push-button press before starting the Communication.
     In the meantime, LED4 is blinking */
  while(UserButtonStatus == 0)
  {
      /* Toggle LED4*/
      BSP_LED_Toggle(LED4); 
      HAL_Delay(100);
  }
  
  BSP_LED_Off(LED4); 
#endif

  /*##-1- Configure the UART peripheral ######################################*/
  /* Put the USART peripheral in the Asynchronous mode (UART Mode) */
  /* UART configured as follows:
      - Word Length = 8 Bits
      - Stop Bit = One Stop bit
      - Parity = None
      - BaudRate = 9600 baud
      - Hardware flow control disabled (RTS and CTS signals) */
  UartHandle.Instance        = USARTx;

  UartHandle.Init.BaudRate   = 9600;
  UartHandle.Init.WordLength = UART_WORDLENGTH_8B;
  UartHandle.Init.StopBits   = UART_STOPBITS_1;
  UartHandle.Init.Parity     = UART_PARITY_NONE;
  UartHandle.Init.HwFlowCtl  = UART_HWCONTROL_NONE;
  UartHandle.Init.Mode       = UART_MODE_TX_RX;
  UartHandle.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
  if(HAL_UART_DeInit(&UartHandle) != HAL_OK)
  {
    Error_Handler();
  }  
  if(HAL_UART_Init(&UartHandle) != HAL_OK)
  {
    Error_Handler();
  }
  
#ifdef TRANSMITTER_BOARD
  
  /* The board sends the message and expects to receive it back */
  /* DMA is programmed for reception before starting the transmission, in order to
     be sure DMA Rx is ready when board 2 will start transmitting */

  /*##-2- Program the Reception process #####################################*/  
  if(HAL_UART_Receive_DMA(&UartHandle, (uint8_t *)aRxBuffer, RXBUFFERSIZE) != HAL_OK)
  {
    Error_Handler();
  }

  /*##-3- Start the transmission process #####################################*/  
  /* While the UART in reception process, user can transmit data through 
     "aTxBuffer" buffer */
  if(HAL_UART_Transmit_DMA(&UartHandle, (uint8_t*)aTxBuffer, TXBUFFERSIZE)!= HAL_OK)
  {
    Error_Handler();
  }
  
  /*##-4- Wait for the end of the transfer ###################################*/  
  while (UartReady != SET)
  {
  }

  /* Reset transmission flag */
  UartReady = RESET;
  
#else
  
  /* The board receives the message and sends it back */

  /*##-2- Put UART peripheral in reception process ###########################*/  
  if(HAL_UART_Receive_DMA(&UartHandle, (uint8_t *)aRxBuffer, RXBUFFERSIZE) != HAL_OK)
  {
    Error_Handler();
  }

  /*##-3- Wait for the end of the transfer ###################################*/
  /* While waiting for message to come from the other board, LED4 is
     blinking according to the following pattern: a double flash every half-second */  
  while (UartReady != SET)
  {
      BSP_LED_On(LED4); 
      HAL_Delay(100);
      BSP_LED_Off(LED4); 
      HAL_Delay(100);
      BSP_LED_On(LED4); 
      HAL_Delay(100);
      BSP_LED_Off(LED4); 
      HAL_Delay(500); 
  }

  /* Reset transmission flag */
  UartReady = RESET;
  BSP_LED_Off(LED4); 
  
  /*##-4- Start the transmission process #####################################*/  
  /* While the UART in reception process, user can transmit data through 
     "aTxBuffer" buffer */
  if(HAL_UART_Transmit_DMA(&UartHandle, (uint8_t*)aTxBuffer, TXBUFFERSIZE)!= HAL_OK)
  {
    Error_Handler();
  }
  
#endif /* TRANSMITTER_BOARD */
  
  /*##-5- Wait for the end of the transfer ###################################*/  
  while (UartReady != SET)
  {
  }

  /* Reset transmission flag */
  UartReady = RESET;

  /*##-6- Compare the sent and received buffers ##############################*/
  if(Buffercmp((uint8_t*)aTxBuffer,(uint8_t*)aRxBuffer,RXBUFFERSIZE))
  {
    Error_Handler();
  }
   
  /* Turn on LED4 if test passes then enter infinite loop */
  BSP_LED_On(LED4); 
  /* Infinite loop */
  while (1)
  {
  }
}

/**
  * @brief  System Clock Configuration
  *         The system Clock is configured as follow : 
  *            System Clock source            = PLL (HSE)
  *            SYSCLK(Hz)                     = 48000000
  *            HCLK(Hz)                       = 48000000
  *            AHB Prescaler                  = 1
  *            APB1 Prescaler                 = 1
  *            HSE Frequency(Hz)              = 8000000
  *            PREDIV                         = 1
  *            PLLMUL                         = 6
  *            Flash Latency(WS)              = 1
  * @param  None
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  RCC_OscInitTypeDef RCC_OscInitStruct;
  
  /* Select HSE Oscillator as PLL source */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PREDIV = RCC_PREDIV_DIV1;
  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL6;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct)!= HAL_OK)
  {
    /* Initialization Error */
    while(1); 
  }

  /* Select PLL as system clock source and configure the HCLK and PCLK1 clocks dividers */
  RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1);
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1)!= HAL_OK)
  {
    /* Initialization Error */
    while(1); 
  }
}

/**
  * @brief  Tx Transfer completed callback
  * @param  UartHandle: UART handle. 
  * @note   This example shows a simple way to report end of DMA Tx transfer, and 
  *         you can add your own implementation. 
  * @retval None
  */
void HAL_UART_TxCpltCallback(UART_HandleTypeDef *UartHandle)
{
  /* Set transmission flag: trasfer complete*/
  UartReady = SET;

  /* Turn LED3 on: Transfer in transmission process is correct */
  BSP_LED_On(LED3); 
  
}

/**
  * @brief  Rx Transfer completed callback
  * @param  UartHandle: UART handle
  * @note   This example shows a simple way to report end of DMA Rx transfer, and 
  *         you can add your own implementation.
  * @retval None
  */
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *UartHandle)
{
  /* Set transmission flag: trasfer complete*/
  UartReady = SET;

  /* Turn LED3 on: Transfer in reception process is correct */
  BSP_LED_On(LED3);
  
}

/**
  * @brief  UART error callbacks
  * @param  UartHandle: UART handle
  * @note   This example shows a simple way to report transfer error, and you can
  *         add your own implementation.
  * @retval None
  */
void HAL_UART_ErrorCallback(UART_HandleTypeDef *UartHandle)
{
    Error_Handler();
}


/**
  * @brief EXTI line detection callbacks
  * @param GPIO_Pin: Specifies the pins connected EXTI line
  * @retval None
  */
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{
  if(GPIO_Pin == USER_BUTTON_PIN)
  {  
    UserButtonStatus = 1;
  }
}

/**
  * @brief  Compares two buffers.
  * @param  pBuffer1, pBuffer2: buffers to be compared.
  * @param  BufferLength: buffer's length
  * @retval 0  : pBuffer1 identical to pBuffer2
  *         >0 : pBuffer1 differs from pBuffer2
  */
static uint16_t Buffercmp(uint8_t* pBuffer1, uint8_t* pBuffer2, uint16_t BufferLength)
{
  while (BufferLength--)
  {
    if ((*pBuffer1) != *pBuffer2)
    {
      return BufferLength;
    }
    pBuffer1++;
    pBuffer2++;
  }

  return 0;
}

/**
  * @brief  This function is executed in case of error occurrence.
  * @param  None
  * @retval None
  */
static void Error_Handler(void)
{
  /* Turn LED3 on */
  BSP_LED_On(LED3);
  while(1)
  {
    /* Error if LED3 is slowly blinking (1 sec. period) */
    BSP_LED_Toggle(LED3); 
    HAL_Delay(1000); 
  }  
}

#ifdef  USE_FULL_ASSERT

/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(char* file, uint32_t line)
{ 
  /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */

  /* Infinite loop */
  while (1)
  {
  }
}
#endif


/**
  * @}
  */

/**
  * @}
  */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/