芯片：stm32f042

库：hal

1，

//main函数的while(1)上面写下面两句话
__HAL_UART_ENABLE_IT(&huart1, UART_IT_IDLE);
HAL_UART_Receive_DMA(&huart1, (uint8_t*)receive_buff, BUFFER_SIZE);



//main.c底部，这是通过cube配置自动生成的。
static void MX_NVIC_Init(void)
{
 /* USART1_IRQn interrupt configuration */
 HAL_NVIC_SetPriority(USART1_IRQn, 0, 0);
 HAL_NVIC_EnableIRQ(USART1_IRQn);
}

2，

//uart.c里面
#include <string.h>
extern uint8_t receive_buff[BUFFER_SIZE];
#ifdef __GNUC__
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#else
#define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
#endif
PUTCHAR_PROTOTYPE
{
    HAL_UART_Transmit(&huart1, (uint8_t *)&ch, 1, 0xFFFF);
    return ch;
}

3，

//uart.c里面
void MY_UART_IDLECallback(UART_HandleTypeDef *huart)
{
	HAL_UART_DMAStop(&huart1);
	uint8_t data_length=BUFFER_SIZE-__HAL_DMA_GET_COUNTER(&hdma_usart1_rx);
	
	printf("Receive接收 Data_length = %d : ",data_length);
	HAL_UART_Transmit(&huart1,receive_buff,data_length,0x200);
	
	mijia_cmd_chuli(receive_buff,data_length);
	
	printf("\r\n");
	memset(receive_buff,0,data_length);
	data_length = 0;
  HAL_UART_Receive_DMA(&huart1, (uint8_t*)receive_buff, BUFFER_SIZE);
}

void MY_UART_IRQHandler(UART_HandleTypeDef *huart)
{
	if(USART1==huart1.Instance)
	{
		if(RESET != __HAL_UART_GET_FLAG(&huart1,UART_FLAG_IDLE))
		{
			__HAL_UART_CLEAR_IDLEFLAG(&huart1);
			printf("\r\nUART1 Idle IQR Detected\r\n");
		  MY_UART_IDLECallback(huart);
		}
	}
}

4，

//uart.h
extern UART_HandleTypeDef huart1;

#define  BUFFER_SIZE  (255)

void MX_USART1_UART_Init(void);

5，

//stm32f0xx_it.h
extern void MY_UART_IRQHandler(UART_HandleTypeDef *huart);

void DMA1_Channel2_3_IRQHandler(void)
{
  /* USER CODE BEGIN DMA1_Channel2_3_IRQn 0 */

  /* USER CODE END DMA1_Channel2_3_IRQn 0 */
  HAL_DMA_IRQHandler(&hdma_usart1_rx);
  /* USER CODE BEGIN DMA1_Channel2_3_IRQn 1 */

  /* USER CODE END DMA1_Channel2_3_IRQn 1 */
}




void USART1_IRQHandler(void)
{
  /* USER CODE BEGIN USART1_IRQn 0 */

  /* USER CODE END USART1_IRQn 0 */
  HAL_UART_IRQHandler(&huart1);
  /* USER CODE BEGIN USART1_IRQn 1 */
  MY_UART_IRQHandler(&huart1);
  /* USER CODE END USART1_IRQn 1 */
}