求助：使用串口唤醒停止模式，如何把唤醒它的字符打印到串口调试助手上

求助：
最近在做STM32F103停止模式实验，打算用串口发送一个字符来唤醒。现在可以通过串口唤醒，却不能把唤醒它的那个字符，打印到串口调试助手上。希望各位大佬，帮忙提提意见
static void Delay(__IO uint32_t nCount) //延时函数
{
for(; nCount != 0; nCount–);
}

static void SYSCLKConfig_STOP(void) //停机唤醒后配置系统时钟
{
/* After wake-up from STOP reconfigure the system clock /
/ 使能 HSE */
RCC_HSEConfig(RCC_HSE_ON);

    /* 等待 HSE 准备就绪 */
    while (RCC_GetFlagStatus(RCC_FLAG_HSERDY) == RESET);

    /* 使能 PLL */ 
    RCC_PLLCmd(ENABLE);

    /* 等待 PLL 准备就绪 */
    while (RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET);

    /* 选择PLL作为系统时钟源 */
    RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);

    /* 等待PLL被选为系统时钟源*/
    while (RCC_GetSYSCLKSource() != 0x08);

}

void USARTx_Config(uint32_t BAUDRATE)
{
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB2PeriphClockCmd(USARTx_TX_Clk | USARTx_RX_Clk | USARTx_AFIO_Clk,ENABLE);

    GPIO_InitStructure.GPIO_Pin = USARTx_TX_Pin;                  
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;               
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;            
    GPIO_Init(USARTx_TX_Port,&GPIO_InitStructure);
             
    GPIO_InitStructure.GPIO_Pin = USARTx_RX_Pin;                
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_Init(USARTx_RX_Port,&GPIO_InitStructure);
    USART_DeInit(USARTx);
    USART_InitStructure.USART_BaudRate = BAUDRATE;                
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;  
    USART_InitStructure.USART_StopBits = USART_StopBits_1;       
    USART_InitStructure.USART_Parity = USART_Parity_No;           
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None; 
    USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;                
    USART_Init(USARTx,&USART_InitStructure);
    
    USART_ITConfig(USART1, USART_IT_TXE, DISABLE); 
                        
       
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);          
   NVIC_InitStructure.NVIC_IRQChannel = USARTx_IRQn;           
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;        
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;         
       
    NVIC_Init(&NVIC_InitStructure); 
    USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);          
    USART_Cmd(USARTx,ENABLE);

}

void EXTI_PA10_Config(void)
{
EXTI_InitTypeDef EXTI_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);

    GPIO_EXTILineConfig(GPIO_PortSourceGPIOA,GPIO_PinSource10);
    EXTI_InitStructure.EXTI_Line = EXTI_Line10;
    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
    EXTI_InitStructure.EXTI_LineCmd = ENABLE;
                                
    NVIC_InitStructure.NVIC_IRQChannel = EXTI15_10_IRQn;      
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x01;         
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;          
       
    NVIC_Init(&NVIC_InitStructure); 
    EXTI_Init(&EXTI_InitStructure);        

}

int main(void)
{
LED_GPIO_Config();
USARTx_Config(115200);
EXTI_PA10_Config();

    printf("\r\n 停止模式实验\r\n");
    while(1)
    {                
            Delay(0x1FFFFF);          // 延时，不那么快进入停止模式
            
            printf("\r\n 进入停止模式，LED灯亮\r\n");
            LED(ON);
            /* 进入停止模式，设置电压调节器为低功耗模式，等待中断唤醒 */
            PWR_EnterSTOPMode(PWR_Regulator_LowPower,PWR_STOPEntry_WFI);        
                    
            //从停止模式下，被唤醒后使用的是HSI时钟，此处重启HSI时钟，使用PLLCLK
            SYSCLKConfig_STOP();

            Delay(0x0FFFF);          //延时        
                    
            printf("\r\n 已退出停止模式\r\n");

}
}

void EXTI15_10_IRQHandler(void)
{
if(EXTI_GetITStatus(EXTI_Line10) != RESET)
{
LED(OFF);
EXTI_ClearITPendingBit(EXTI_Line10);
}
}
//接收字符
void USART1_IRQHandler(void)
{
uint8_t ucTemp;
if(USART_GetITStatus(USARTx,USART_IT_RXNE)!=RESET)
{
ucTemp = USART_ReceiveData(USARTx);
printf(“串口发送字符为:”);
printf("%c\r\n",ucTemp);
}
}