stm32 UART串口

void USART1_IRQHandler(void)                    //´®¿Ú1ÖжϷþÎñ³ÌÐò
    {
    u8 Res;
#ifdef OS_TICKS_PER_SEC         //Èç¹ûʱÖÓ½ÚÅÄÊý¶¨ÒåÁË,˵Ã÷ҪʹÓÃucosIIÁË.
    OSIntEnter();    
#endif
    if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)  //½ÓÊÕÖжÏ(½ÓÊÕµ½µÄÊý¾Ý±ØÐëÊÇ0x0d 0x0a½áβ)
        {
            
        Res =USART_ReceiveData(USART1);//(USART1->DR);    //¶ÁÈ¡½ÓÊÕµ½µÄÊý¾Ý
        
            if(Res==0x31)
            {
            //LED0ÉÁÒ»´Î
            LED0 = 0;    
          delay_ms(300);
            LED0 = 1;
          delay_ms(50);
            LED0 = 0;
            delay_ms(300);
            LED0 = 1;    
            }
        //LED1 ÁÁ
            if(Res==0x32)
            {
                
                LED1 = 0;
                
            }
 
            
        if((USART_RX_STA&0x8000)==0)//½ÓÊÕδÍê³É
            {
            if(USART_RX_STA&0x4000)  //½ÓÊÕµ½ÁË0x0d
                {
                if(Res!=0x0a)USART_RX_STA=0;//½ÓÊÕ´íÎó,ÖØпªÊ¼
                else USART_RX_STA|=0x8000;    //½ÓÊÕÍê³ÉÁË 
                }
            else //»¹Ã»ÊÕµ½0X0D
                {    
                if(Res==0x0d)USART_RX_STA|=0x4000;
                else
                    {
                    USART_RX_BUF[USART_RX_STA&0X3FFF]=Res ;
                    USART_RX_STA++;
                    if(USART_RX_STA>(USART_REC_LEN-1))USART_RX_STA=0;//½ÓÊÕÊý¾Ý´íÎó,ÖØпªÊ¼½ÓÊÕ      
                    }         
                }
            }            
     } 

while(1)
    {
        if(USART_RX_STA&0x8000)
        {                       
            len=USART_RX_STA&0x3fff;//µÃµ½´Ë´Î½ÓÊÕµ½µÄÊý¾Ý³¤¶È
            printf("\r\nÄú·¢Ë͵ÄÏûϢΪ:\r\n\r\n");
            for(t=0;t<len;t++)
            {
                USART_SendData(USART1, USART_RX_BUF[t]);//Ïò´®¿Ú1·¢ËÍÊý¾Ý
                while(USART_GetFlagStatus(USART1,USART_FLAG_TC)!=SET);//µÈ´ý·¢ËͽáÊø
            }
            printf("\r\n\r\n");//²åÈë»»ÐÐ
            USART_RX_STA=0;
        } 
         else
             
        {
            times++;
         if(times%200==0)printf("\r\nѧºÅ:14160310317ÐÕÃû:ÕÔ´æµµ µÈ´ýKEY0 KEY1 ±»°´ÏÂ\r\n"); 
     delay_ms(10);            
         t=KEY_Scan(0);
        if(t)
        {                           
            switch(t)
            {                 
                case KEY_UP:
              printf("\r\nKEY0±»°´ÏÂ\r\n\r\n");
              break;
                case KEY_LEFT:
                    BEEP=1;
                  delay_ms(300);
                  BEEP=0;
                break;
            }            
        }
    }     
 }