STM32F4探索板 Usart2使用问题

张明涛 · 发表于 2017-10-17 12:39:36

把STM32F4开发板的串口通讯例程中的Usart1修改为usart2，其余不变，代码如下
void My_USART2_Init(void)
{
   GPIO_InitTypeDef  GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE);//ê1ÄüUSART2ê±Öó
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA,ENABLE);

GPIO_PinAFConfig(GPIOA,GPIO_PinSource2,GPIO_AF_USART2);
GPIO_PinAFConfig(GPIOA,GPIO_PinSource3,GPIO_AF_USART2);

   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

USART_InitStructure.USART_BaudRate=115200;
USART_InitStructure.USART_HardwareFlowControl=USART_HardwareFlowControl_None;
USART_InitStructure.USART_Mode=USART_Mode_Rx|USART_Mode_Tx;
USART_InitStructure.USART_Parity=USART_Parity_No;
USART_InitStructure.USART_StopBits=USART_StopBits_1;
USART_InitStructure.USART_WordLength=USART_WordLength_8b;

USART_Init(USART2,&USART_InitStructure);
USART_Cmd(USART2 ,ENABLE);

USART_ITConfig(USART2,USART_IT_RXNE,ENABLE);

NVIC_InitStructure.NVIC_IRQChannel=USART2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority=1;
NVIC_Init(&NVIC_InitStructure);

}

void USART2_IRQHandler(void)
{
u8 res;
if(USART_GetITStatus(USART2,USART_IT_RXNE)){

res=USART_ReceiveData(USART2);
USART_SendData(USART2,res);
}

}
int main(void)
{
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
My_USART2_Init();
while(1);
}

但是串口调试助手怎么收不到数据呢？麻烦哪位高人指点下？