stm32 串口出错

只看该作者 · 2016-7-27 08:33

我用stm32  库函数调串口  数据不对波特率19200 每位宽大概50us 实际输出每位宽是80us  这样的话我发一个数上位机收到两个  求助？？
void RCC_Configuration(void)
{

ErrorStatus HSEStartUpStatus;

  /* 复位系统时钟设置*/
  RCC_DeInit();

  /* 开启HSE*/
  RCC_HSEConfig(RCC_HSE_ON);

  /* 等待HSE起震并稳定*/
  HSEStartUpStatus = RCC_WaitForHSEStartUp();

/* HSE是否起振成功 */
  if(HSEStartUpStatus == SUCCESS)
  {
/* HCLK(AHB)时钟源为SYSCLK 1分频*/
RCC_HCLKConfig(RCC_SYSCLK_Div1);

/* PCLK2时钟源为HCLK(AHB) 1分频 */
RCC_PCLK2Config(RCC_HCLK_Div1);

/* PCLK1时钟源为HCLK(AHB) 2分频 */
RCC_PCLK1Config(RCC_HCLK_Div2);

/* 设置FLASH延时周期为2 */
FLASH_SetLatency(FLASH_Latency_2);
/* 使能FLASH预取缓存 */
FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);

/* 6MHz * 12 = 72MHz */
RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_12);

RCC_PLLCmd(ENABLE);

while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET);

RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK); //选择SYSCLK的时钟源为PLL

while(RCC_GetSYSCLKSource() != 0x08);
  }

  /* 打开APB2总线上的GPIOA时钟*/
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA , ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2 , ENABLE);
}
void GPIO_Configuration(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;

  /* 设置PA2,PA3口为推挽输出，最大翻转频率为50MHz*/
  GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_2;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;    //复用推挽输出
  GPIO_Init(GPIOA , &GPIO_InitStructure);

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;
//GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;  //浮空输入
GPIO_Init(GPIOA, &GPIO_InitStructure);
}
void UART_Configuration(void)
{
USART_InitTypeDef USART_InitStructure;
USART_InitStructure.USART_BaudRate = 19200;
USART_InitStructure.USART_WordLength = USART_WordLength_8b; //数据8位
USART_InitStructure.USART_StopBits = USART_StopBits_1;  //停止位1位
  USART_InitStructure.USART_Parity = USART_Parity_No; //无校验位
  USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;//打开接收和发送
  USART_Init(USART2, &USART_InitStructure);
USART_Cmd(USART2, ENABLE);

}