STM32CubeMX 串口空闲中断加DMA 实现不定长度收发数据

来源：互联网发布：山西证券交易软件编辑：程序博客网时间：2024/06/05 22:46

这里教程是选择的STM32F407。STM32F103也测试过。

1.首先选择串口，选择异步通信。

2.添加DMA

3.打开中断

4.生成代码，生成代码选择了每个外设单独使用.c/.h

5.我使用的是Keil5。打开工程，首先注释掉dma.c里的DMA接收中断，因为不需要DMA接收中断，DMA发送中断是需要的。(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文件里定义串口接收数据类型我是如下定义的(usart.h)

/* USER CODE BEGIN Private defines */#define RECEIVELEN 1024#define USART_DMA_SENDING 1//发送未完成#define USART_DMA_SENDOVER 0//发送完成typedef struct{uint8_t receive_flag:1;//空闲接收标记uint8_t dmaSend_flag:1;//发送完成标记uint16_t rx_len;//接收长度uint8_t usartDMA_rxBuf[RECEIVELEN];//DMA接收缓存}USART_RECEIVETYPE; extern USART_RECEIVETYPE UsartType1;/* USER CODE END Private defines */

7.然后在usart.c里需要添加空闲中断处理函数，以及DMA发送函数等。(usart.c)

首先定义串口数据类型：

/* USER CODE BEGIN 0 */USART_RECEIVETYPE UsartType1;/* USER CODE END 0 */

然后定义空闲中断处理函数和DMA发送函数

/* 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发送函数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发送完成中断回调函数void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart){ __HAL_DMA_DISABLE(huart->hdmatx);UsartType1.dmaSend_flag = USART_DMA_SENDOVER;}//串口接收空闲中断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.在中断文件里添加(当然，上面的空闲中断处理函数需要声明)(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.主函数里，打开空闲中断，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.然后就可以在while(1)里处理数据了

/* Infinite loop */  /* USER CODE BEGIN WHILE */  while (1)  {if(UsartType1.receive_flag)//如果产生了空闲中断{UsartType1.receive_flag=0;//清零标记Usart1SendData_DMA(UsartType1.usartDMA_rxBuf,UsartType1.rx_len);//串口打印收到的数据。}  /* USER CODE END WHILE */  /* USER CODE BEGIN 3 */  }  /* USER CODE END 3 */

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