串口发送数据失败，串口助手上显示不出来发送的内容

但是单片机可以接受到串口助手发送的消息，我用的是原子的示例代码，串口连接线的什么肯定没错，我检查好几遍了。就是不知道出现了什么问题，printf和函数发送都不行。

[mw_shl_code=applescript,true]int main(void)
{
        u16 times=0;  
        NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);//éèÖÃÏμí3ÖD¶ÏóÅÏ輶·Ö×é2
        delay_init(168);                //Ñóê±3õê¼»ˉ
        uart_init(115200);        //′®¿ú3õê¼»ˉ2¨ìØÂêÎa115200
        LED_Init();                                  //3õê¼»ˉóëLEDᬽóμÄó2¼t½ó¿ú  
        while(1)
        {
    printf("n ");
                USART_SendData(USART1,'d');
                delay_ms(200);
        }
}



[/mw_shl_code]

[mw_shl_code=applescript,true]void USART1_IRQHandler(void)                        //′®¿ú1ÖD¶Ï·tÎñ3ìDò
{
        if(USART_ReceiveData(USART1)=='S')
        {
                GPIO_SetBits(GPIOD,GPIO_Pin_12 | GPIO_Pin_13| GPIO_Pin_14| GPIO_Pin_15);
        }
        if(USART_ReceiveData(USART1)=='Q')
        {
                GPIO_ResetBits(GPIOD,GPIO_Pin_12 | GPIO_Pin_13| GPIO_Pin_14| GPIO_Pin_15);
        }        [/mw_shl_code]

[mw_shl_code=applescript,true]void uart_init(u32 bound){
   //GPIO¶Ë¿úéèÖÃ
  GPIO_InitTypeDef GPIO_InitStructure;
        USART_InitTypeDef USART_InitStructure;
        NVIC_InitTypeDef NVIC_InitStructure;
       
        RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA,ENABLE); //ê1ÄüGPIOAê±Öó
        RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1,ENABLE);//ê1ÄüUSART1ê±Öó

        //′®¿ú1¶Ôó|òy½Å¸′óÃó3éä
        GPIO_PinAFConfig(GPIOA,GPIO_PinSource9,GPIO_AF_USART1); //GPIOA9¸′óÃÎaUSART1
        GPIO_PinAFConfig(GPIOA,GPIO_PinSource10,GPIO_AF_USART1); //GPIOA10¸′óÃÎaUSART1
       
        //USART1¶Ë¿úÅäÖÃ
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9 | GPIO_Pin_10; //GPIOA9óëGPIOA10
        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//¸′óÃ1|Äü
        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;        //Ëù¶è50MHz
        GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //íÆíì¸′óÃêä3ö
        GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; //éÏà-
        GPIO_Init(GPIOA,&GPIO_InitStructure); //3õê¼»ˉPA9￡&#172A10

   //USART1 3õê¼»ˉéèÖÃ
        USART_InitStructure.USART_BaudRate = bound;//2¨ìØÂêéèÖÃ
        USART_InitStructure.USART_WordLength = USART_WordLength_8b;//×Ö3¤Îa8λêy¾Y¸ñê½
        USART_InitStructure.USART_StopBits = USART_StopBits_1;//ò»¸öí￡Ö1λ
        USART_InitStructure.USART_Parity = USART_Parity_No;//ÎTÆæżD￡Ñéλ
        USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//ÎTó2¼têy¾Yá÷¿ØÖÆ
        USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;        //êÕ·￠Ä￡ê½
  USART_Init(USART1, &USART_InitStructure); //3õê¼»ˉ′®¿ú1
       
  USART_Cmd(USART1, ENABLE);  //ê1Äü′®¿ú1
       
        //USART_ClearFlag(USART1, USART_FLAG_TC);
       
#if EN_USART1_RX       
        USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);//¿aÆôÏà1ØÖD¶Ï

        //Usart1 NVIC ÅäÖÃ
  NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;//′®¿ú1ÖD¶Ïí¨μà
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3;//ÇàÕ¼óÅÏ輶3
        NVIC_InitStructure.NVIC_IRQChannelSubPriority =3;                //×óóÅÏ輶3
        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;                        //IRQí¨μàê1Äü
        NVIC_Init(&NVIC_InitStructure);        //¸ù¾YÖ¸¶¨μÄ2Îêy3õê¼»ˉVIC¼Ä′æÆ÷¡￠

#endif
       
}[/mw_shl_code]