串口通讯问题

x88484532 · 发表于 2017-10-14 09:41:46

原来用的串口1，通讯正常，后来改板子，换成了串口2，不能使用了
代码如下：
u16 USART2_RX_STA=0;

void u3_printf(char* fmt,...)
{
u8 i,j;
va_list ap;
va_start(ap,fmt);
vsprintf((char*)send_buf,fmt,ap);
va_end(ap);
i=strlen((const char*)send_buf);//此次发送数据的长度
for(j=0;j<i;j++)//循环发送数据
{
      while(USART_GetFlagStatus(USART2,USART_FLAG_TC)==RESET);  //等待上次传输完成
//这句死循环，出不来了？
USART_SendData(USART2,(uint8_t)send_buf[j]);    //发送数据到串口1
}
}

配置如下：
void USART2_InitConfig(uint32 BaudRate)
{
GPIO_InitTypeDef GPIO_InitStructure;
  USART_InitTypeDef USART_InitStructure;
USART_ClockInitTypeDef USART_ClockInitStructure;

RCC_APB2PeriphClockCmd(RCC_APB1Periph_USART2|RCC_APB2Periph_GPIOA|RCC_APB2Periph_AFIO,ENABLE);

USART_DeInit(USART2);  //复位串口2

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);

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;
  GPIO_InitStructure.GPIO_Mode =  GPIO_Mode_IN_FLOATING;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  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_ClockInitStructure.USART_Clock = USART_Clock_Disable;
  USART_ClockInitStructure.USART_CPOL = USART_CPOL_Low;
  USART_ClockInitStructure.USART_CPHA = USART_CPHA_2Edge;
  USART_ClockInitStructure.USART_LastBit = USART_LastBit_Disable;

  USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);
  /* Configure USART2 */
  USART_Init(USART2, &USART_InitStructure); //初始化串口2

  /* Enable the USART2 */
  USART_Cmd(USART2, ENABLE);    //使能串口
USART_ClearFlag(USART2,USART_FLAG_TC);

}

void NVIC_Configuration(void)
{
NVIC_InitTypeDef NVIC_InitStructure;

  NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
TIM7_Int_Init(1000-1,8400-1); //100ms中断
USART2_RX_STA=0; //清零
TIM_Cmd(TIM7, DISABLE); //关闭定时器7
}

void TIM7_IRQHandler(void)
{
if (TIM_GetITStatus(TIM7, TIM_IT_Update) != RESET)//是更新中断
{
USART2_RX_STA|=1<<15; //标记接收完成
TIM_ClearITPendingBit(TIM7, TIM_IT_Update  );  //清除TIM7更新中断标志
TIM_Cmd(TIM7, DISABLE);  //关闭TIM7
}
}

void TIM7_Int_Init(u16 arr,u16 psc)
{
NVIC_InitTypeDef NVIC_InitStructure;
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM7, ENABLE);//TIM7时钟使能

//定时器TIM7初始化
TIM_TimeBaseStructure.TIM_Period = arr; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值
TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; //设置时钟分割:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //TIM向上计数模式
TIM_TimeBaseInit(TIM7, &TIM_TimeBaseStructure); //根据指定的参数初始化TIMx的时间基数单位

TIM_ITConfig(TIM7,TIM_IT_Update,ENABLE ); //使能指定的TIM7中断,允许更新中断


NVIC_InitStructure.NVIC_IRQChannel = TIM7_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0 ;//抢占优先级0
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; //子优先级1
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

}

void USART2_IRQHandler(void)
{
u8 res,i,j,flag = 0;
u32 lishi;
if(USART_GetITStatus(USART2, USART_IT_RXNE) != RESET)//接收到数据
{
res =USART_ReceiveData(USART2);
if((USART2_RX_STA&(1<<15))==0)//接收完的一批数据,还没有被处理,则不再接收其他数据
{
if(USART2_RX_STA<64) //还可以接收数据
{
TIM_SetCounter(TIM7,0);//计数器清空
if(USART2_RX_STA==0)
TIM_Cmd(TIM7, ENABLE);  //使能定时器7
recv_buf[USART2_RX_STA++]=res; //记录接收到的值
}else
{
USART2_RX_STA|=1<<15; //强制标记接收完成
}
}
}
}