目录

一、轮询模式

1.1 配置USART2为异步模式

 1.2 500ms发送一次消息

 1.3 通信结果

 1.4 串口控制LED

二、中断收发

2.1 开启中断

2.2 中断发送接收

2.2.1 中断发送只需要调用接口

2.2.2 中断接收

2.3 实验结果

三、DMA模式与收发不定长数据

3.1 DMA通道配置

3.2  DMA发送接收函数

3.3 使用空闲中断接收不定长数据

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一、轮询模式

1.1 配置USART2为异步模式

 1.2 500ms发送一次消息

 1.3 通信结果

 1.4 串口控制LED

  uint8_t reciveDate[2];while (1){HAL_UART_Receive(&huart1, reciveDate, 2, HAL_MAX_DELAY);HAL_UART_Transmit(&huart1, reciveDate, 2, 100);GPIO_PinState state=GPIO_PIN_SET;if(reciveDate[1]=='1'){state=GPIO_PIN_RESET;}if(reciveDate[0]=='R'){HAL_GPIO_WritePin(GPIOA, GPIO_PIN_8, state);}else if(reciveDate[0]=='G'){HAL_GPIO_WritePin(GPIOD, GPIO_PIN_2, state);}}
}

二、中断收发

2.1 开启中断

2.2 中断发送接收

2.2.1 中断发送只需要调用接口

HAL_UART_Transmit_IT(&huart1, reciveDate, 2);

2.2.2 中断接收

①在程序起始开启中断

 ②重新定义stm32f1xx_hal_uart.c中的函数

__weak void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{/* Prevent unused argument(s) compilation warning */UNUSED(huart);/* NOTE: This function should not be modified, when the callback is needed,the HAL_UART_RxCpltCallback could be implemented in the user file*/
}

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{HAL_UART_Transmit_IT(&huart1, reciveDate, 2);GPIO_PinState state = GPIO_PIN_SET;if (reciveDate[1] == '1'){state = GPIO_PIN_RESET;}if (reciveDate[0] == 'G'){HAL_GPIO_WritePin(GPIOD, GPIO_PIN_2, state);}HAL_UART_Receive_IT(&huart1, reciveDate, 2);//再次启动中断接收
}

2.3 实验结果

三、DMA模式与收发不定长数据

3.1 DMA通道配置

3.2  DMA发送接收函数

只需要将_IT修改为_DMA即可，DMA模式还是有中断参与其中

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{HAL_UART_Transmit_DMA(&huart1, reciveDate, 2);//dma发送GPIO_PinState state = GPIO_PIN_SET;if (reciveDate[1] == '1'){state = GPIO_PIN_RESET;}if (reciveDate[0] == 'G'){HAL_GPIO_WritePin(GPIOD, GPIO_PIN_2, state);}HAL_UART_Receive_DMA(&huart1, reciveDate, 2);//DMA接收
}

3.3 使用空闲中断接收不定长数据

只有当接收端不再有数据输入时才会触发空闲中断，重新定义

__weak void HAL_UARTEx_RxEventCallback(UART_HandleTypeDef *huart, uint16_t Size)
{/* Prevent unused argument(s) compilation warning */UNUSED(huart);UNUSED(Size);/* NOTE : This function should not be modified, when the callback is needed,the HAL_UARTEx_RxEventCallback can be implemented in the user file.*/
}

void HAL_UARTEx_RxEventCallback(UART_HandleTypeDef *huart, uint16_t Size)
{if(huart==&huart1){HAL_UART_Transmit_DMA(&huart1, reciveDate, Size);//发�?�与接收相同的Size长度的字节数HAL_UARTEx_ReceiveToIdle_DMA(&huart1, reciveDate, sizeof(reciveDate));//接收不定长数�?}
}