求教串口2 用开发板测试只能发不能收。

zyjzjh2003

void USART2_Config(u32 bound) 
{    
GPIO_InitTypeDef GPIO_InitStructure; //定义初始化GPIO的结构体 
USART_InitTypeDef USART2_InitStructure; //定义初始化USART的结构体 
NVIC_InitTypeDef NVIC_InitStructure;
/*配置USART2时钟*/ 
//RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2|RCC_APB2Periph_GPIOA,ENABLE); 
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE); 
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE); 
/*USART2端口配置*/ 
/*USART2 Tx(PA0.2) 开漏推挽*/ 
GPIO_InitStructure.GPIO_Pin=GPIO_Pin_2; 
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP; 
GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz; 
GPIO_Init(GPIOA,&GPIO_InitStructure); 
/*USART1 Rx(PA0.3) 开路输入*/ 
GPIO_InitStructure.GPIO_Pin=GPIO_Pin_3; 
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_IN_FLOATING; 
GPIO_Init(GPIOA,&GPIO_InitStructure); 
/*USART2 模式配置*/ 
  NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//抢占优先级3
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2; //子优先级3
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道使能
NVIC_Init(&NVIC_InitStructure); //根据指定的参数初始化VIC寄存器

USART2_InitStructure.USART_BaudRate=bound; 
USART2_InitStructure.USART_WordLength=USART_WordLength_8b; 
USART2_InitStructure.USART_StopBits=USART_StopBits_1; 
USART2_InitStructure.USART_Parity=USART_Parity_No; 
USART2_InitStructure.USART_HardwareFlowControl=USART_HardwareFlowControl_None; 
USART2_InitStructure.USART_Mode=USART_Mode_Rx|USART_Mode_Tx; 
USART_Init(USART2,&USART2_InitStructure); 
USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);//开启串口接受中断
/*使能USART2*/ 
USART_Cmd(USART2,ENABLE); 
} 
void USART2_IRQHandler(void)                 //串口2中断服务程序
{
u8 Res;
#if SYSTEM_SUPPORT_OS //如果SYSTEM_SUPPORT_OS为真，则需要支持OS.
OSIntEnter();    
#endif
if(USART_GetITStatus(USART2, USART_IT_RXNE) != RESET)  //接收中断(接收到的数据必须是0x0d 0x0a结尾)
{
Res =USART_ReceiveData(USART2); //读取接收到的数据

if((USART_RX_STA&0x8000)==0)//接收未完成
{
if(USART_RX_STA&0x4000)//接收到了0x0d
{
if(Res!=0x0a)USART_RX_STA=0;//接收错误,重新开始
else USART_RX_STA|=0x8000; //接收完成了 
}
else //还没收到0X0D
{
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;//接收数据错误,重新开始接收  
}  
}
}    
     } 
#if SYSTEM_SUPPORT_OS //如果SYSTEM_SUPPORT_OS为真，则需要支持OS.
OSIntExit();    
#endif
}