时钟配置HSI主频配置64M

配置好串口，选择异步模式

配置DMA TX,RX,选择循环模式。

NVIC中勾选使能中断

勾选生成独立的.c和h文件

配置好需要的开发环境并获取代码

 串口重定向勾选Use Micro LIB

 main.c文件修改

增加头文件和串口重定向

#include <string.h>

int fputc(int ch, FILE *f)
{
  HAL_UART_Transmit(&huart1, (uint8_t *)&ch, 1, 0xFFFF);

  return ch;
}

main函数修改

  printf("hello world\r\n");
  while (1)
  {
	if(USART1_RECV_FLAG == 1)
	{
		printf("rx_len = %d \r\n",USART1_RX_LEN);
		HAL_UART_Transmit(&huart1,USART1_RX_BUF, USART1_RX_LEN,200);

		memset(USART1_RX_BUF,0,USART1_RX_BUF_SIZE);
		USART1_RX_LEN = 0;
		USART1_RECV_FLAG = 0;
	}
	HAL_UART_Receive_DMA(&huart1,USART1_RX_BUF,USART1_RX_BUF_SIZE);
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
  }

usart.c文件修改

增加定义

uint8_t USART1_RX_LEN = 0;             
uint8_t USART1_RECV_FLAG = 0;     
uint8_t USART1_RX_BUF[USART1_RX_BUF_SIZE]={0};   

修改void MX_USART1_UART_Init(void)函数

void MX_USART1_UART_Init(void)
{

  /* USER CODE BEGIN USART1_Init 0 */

  /* USER CODE END USART1_Init 0 */

  /* USER CODE BEGIN USART1_Init 1 */

  /* USER CODE END USART1_Init 1 */
  huart1.Instance = USART1;
  huart1.Init.BaudRate = 115200;
  huart1.Init.WordLength = UART_WORDLENGTH_8B;
  huart1.Init.StopBits = UART_STOPBITS_1;
  huart1.Init.Parity = UART_PARITY_NONE;
  huart1.Init.Mode = UART_MODE_TX_RX;
  huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart1.Init.OverSampling = UART_OVERSAMPLING_16;
  huart1.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
  huart1.Init.ClockPrescaler = UART_PRESCALER_DIV1;
  huart1.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
  if (HAL_UART_Init(&huart1) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_SetTxFifoThreshold(&huart1, UART_TXFIFO_THRESHOLD_1_8) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_SetRxFifoThreshold(&huart1, UART_RXFIFO_THRESHOLD_1_8) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_DisableFifoMode(&huart1) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN USART1_Init 2 */

  /* USER CODE END USART1_Init 2 */
  __HAL_UART_ENABLE_IT(&huart1,UART_IT_IDLE);
  HAL_UART_Receive_DMA(&huart1,USART1_RX_BUF,USART1_RX_BUF_SIZE);
}

usart.h文件修改

增加头文件和定义声明

#include "stdio.h"

#define USART1_RX_BUF_SIZE 512
extern  uint8_t USART1_RX_LEN;             
extern  uint8_t USART1_RECV_FLAG;     
extern uint8_t USART1_RX_BUF[USART1_RX_BUF_SIZE];  

stm32g0xx_it.c文件修改

增加头文件

#include "usart.h"

修改void USART1_IRQHandler(void)函数

void USART1_IRQHandler(void)
{
  /* USER CODE BEGIN USART1_IRQn 0 */
	uint32_t temp;

  if((__HAL_UART_GET_FLAG(&huart1,UART_FLAG_IDLE) != RESET))
  {
	  __HAL_UART_CLEAR_IDLEFLAG(&huart1);
	  HAL_UART_DMAStop(&huart1);
	  temp  =  __HAL_DMA_GET_COUNTER(&hdma_usart1_rx);
	  USART1_RX_LEN =  USART1_RX_BUF_SIZE - temp; 

	  USART1_RECV_FLAG = USART1_RX_LEN ? 1 : 0;  
	  HAL_UART_Receive_DMA(&huart1,USART1_RX_BUF,USART1_RX_BUF_SIZE);
  }

  /* USER CODE END USART1_IRQn 1 */
}

编译后连上串口工具调试