1，#include "stdio.h"
2，重写宏
int fputc(int ch, FILE *f)
{
/* ·¢ËÍÒ»¸ö×Ö½ÚÊý¾Ýµ½USART1 */
USART_SendData(USART3, (uint8_t) ch);
/* µÈ´ý·¢ËÍÍê±Ï */
while (USART_GetFlagStatus(USART3, USART_FLAG_TXE) == RESET);
return (ch);
}
3，用下面的库