串口printf,scanf编写

HAL_UART_Transmit(&huart1, (uint8_t*)"hello\r\n",5,0xFFFF);
printf("hahaha");
HAL_Delay(1000);

uint8_t buf[5];
HAL_UART_Receive(&huart1,buf,3,0xFFFF);// 句柄，缓存空间首地址，指定字节长度，等待时间

HAL_UART_Transmit(&huart1,buf,3,0xFFFF);
int val=0;
scanf("%d",&val);
printf("%d\r\n",val);


/**********************printf重定向****************************/
// 需要调用stdio.h文件
#include <stdio.h>
int fputc(int c, FILE *stream)
{  
	uint8_t ch[1]={c};
	HAL_UART_Transmit(&huart1, ch, 1, 0xFFFF);
	return c;
}

int fgetc(FILE *stream)
{  
	uint8_t ch[1];
	HAL_UART_Receive(&huart1, ch, 1, 0xFFFF);
	return ch[0];
}
		
int val=0;
scanf("%d",&val);
printf("%d\r\n",val);