STM32CubeMX 序列槽空閑中斷加DMA 實作不定長度收發資料

這裡教程是選擇的STM32F407。STM32F103也測試過。

1.首先選擇序列槽，選擇異步通信。

2.添加DMA

3.打開中斷

4.生成代碼，生成代碼選擇了每個外設單獨使用.c/.h

5.我使用的是Keil5。打開工程，首先注釋掉dma.c裡的DMA接收中斷，因為不需要DMA接收中斷，DMA發送中斷是需要的。(dma.c)

void MX_DMA_Init(void) 
{
  /* DMA controller clock enable */
  __HAL_RCC_DMA2_CLK_ENABLE();

  /* DMA interrupt init */
  /* DMA2_Stream0_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(DMA2_Stream0_IRQn, 2, 0);
  HAL_NVIC_EnableIRQ(DMA2_Stream0_IRQn);
  /* DMA2_Stream2_IRQn interrupt configuration */
//  HAL_NVIC_SetPriority(DMA2_Stream2_IRQn, 0, 0);
//  HAL_NVIC_EnableIRQ(DMA2_Stream2_IRQn);
  /* DMA2_Stream7_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(DMA2_Stream7_IRQn, 1, 0);
  HAL_NVIC_EnableIRQ(DMA2_Stream7_IRQn);

}
           

6.在usart.h檔案裡定義序列槽接收資料類型我是如下定義的(usart.h)

/* USER CODE BEGIN Private defines */
#define RECEIVELEN 1024
#define USART_DMA_SENDING 1//發送未完成
#define USART_DMA_SENDOVER 0//發送完成
typedef struct
{
uint8_t receive_flag:1;//空閑接收标記
uint8_t dmaSend_flag:1;//發送完成标記
uint16_t rx_len;//接收長度
uint8_t usartDMA_rxBuf[RECEIVELEN];//DMA接收緩存
}USART_RECEIVETYPE;
 
extern USART_RECEIVETYPE UsartType1;


/* USER CODE END Private defines */
           

7.然後在usart.c裡需要添加空閑中斷處理函數，以及DMA發送函數等。(usart.c)

首先定義序列槽資料類型：

/* USER CODE BEGIN 0 */

USART_RECEIVETYPE UsartType1;

/* USER CODE END 0 */
           

然後定義空閑中斷處理函數和DMA發送函數

/* USER CODE BEGIN 1 */
#ifdef __GNUC__

  /* With GCC/RAISONANCE, small printf (option LD Linker->Libraries->Small printf
 set to 'Yes') calls __io_putchar() */
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#else

  #define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
#endif /* __GNUC__ */
	
PUTCHAR_PROTOTYPE
{
	HAL_UART_Transmit(&huart1 , (uint8_t *)&ch, 1, 0xFFFF);
	return ch;
}

//DMA發送函數
void Usart1SendData_DMA(uint8_t *pdata, uint16_t Length)
{
	while(UsartType1.dmaSend_flag == USART_DMA_SENDING);
	UsartType1.dmaSend_flag = USART_DMA_SENDING;
	HAL_UART_Transmit_DMA(&huart1, pdata, Length);
}

//DMA發送完成中斷回調函數
void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart)
{
	 __HAL_DMA_DISABLE(huart->hdmatx);
	UsartType1.dmaSend_flag = USART_DMA_SENDOVER;
}

//序列槽接收空閑中斷
void UsartReceive_IDLE(UART_HandleTypeDef *huart)
{
	uint32_t temp;

	if((__HAL_UART_GET_FLAG(huart,UART_FLAG_IDLE) != RESET))
	{ 
		__HAL_UART_CLEAR_IDLEFLAG(&huart1);
		HAL_UART_DMAStop(&huart1);
		temp = huart1.hdmarx->Instance->NDTR;
		UsartType1.rx_len =  RECEIVELEN - temp; 
		UsartType1.receive_flag=1;
		HAL_UART_Receive_DMA(&huart1,UsartType1.usartDMA_rxBuf,RECEIVELEN);
	}
}

/* USER CODE END 1 */
           

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8.在中斷檔案裡添加(當然，上面的空閑中斷處理函數需要聲明)(stm32f4xxit.c)

void USART1_IRQHandler(void)
{
  /* USER CODE BEGIN USART1_IRQn 0 */
	UsartReceive_IDLE(&huart1);
  /* USER CODE END USART1_IRQn 0 */
  HAL_UART_IRQHandler(&huart1);
  /* USER CODE BEGIN USART1_IRQn 1 */

  /* USER CODE END USART1_IRQn 1 */
}
           

9.主函數裡，打開空閑中斷，初始化DMA接收

/* USER CODE BEGIN 2 */
	HAL_UART_Receive_DMA(&huart1, UsartType1.usartDMA_rxBuf, RECEIVELEN);
	__HAL_UART_ENABLE_IT(&huart1, UART_IT_IDLE);
  /* USER CODE END 2 */
           

10.然後就可以在while(1)裡處理資料了

/* Infinite loop */
  /* USER CODE BEGIN WHILE */
	
  while (1)
  {
		if(UsartType1.receive_flag)//如果産生了空閑中斷
		{
			UsartType1.receive_flag=0;//清零标記
			Usart1SendData_DMA(UsartType1.usartDMA_rxBuf,UsartType1.rx_len);//序列槽列印收到的資料。
		}
  /* USER CODE END WHILE */

  /* USER CODE BEGIN 3 */
		
  }
  /* USER CODE END 3 */