STM32串口不断发送数据0，发送管脚是低电平吗

只看该作者 · 2014-9-23 13:28

是这样的我的stm32能接收到数据，但是好像发送不出数据
我用示波器观察始终是低电平，
我硬件仿真的时候串口发送数据0，不是发送管脚的电压时低电平啊

只看该作者 · 2014-9-23 16:49

发送的代码和配置发上来看看啊

只看该作者 · 2014-9-23 17:25

即使你一直发送数据0，每个字节也有起始位，停止位

只看该作者 · 2014-9-23 17:37

weihe123 发表于 2014-9-23 16:49
发送的代码和配置发上来看看啊

找了一天的原因没找到，现在的情况我用示波器测量接收有信号，而发送电平始终是搞电平好像没发送出去
用到的2个串口，串口3负责和外界通讯，串口1用于监测数据接收或发送的数据，监测到的发送接收的数据正常
请教大家指点那里有问题
//主程序
#define  RXBUFFERSIZE  25             //接收数组的个数也是发送数组的个数
uint8_t  TxBuffer[RXBUFFERSIZE];    //·发送数组
int main(void)
{
      USART3_Config();
      USART1_Config();
      NVIC_Configuration();
      NVIC_Configuration1();
      while(1)
      {
      UART3_Send_TxBuffer(TxBuffer,RXBUFFERSIZE );
      }

}

//串口3配置
void USART3_Config(void)
{
      GPIO_InitTypeDef GPIO_InitStructure;
      USART_InitTypeDef USART_InitStructure;

      /* config USART3 clock */
      RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3 , ENABLE);
      RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB| RCC_APB2Periph_AFIO , ENABLE);


      /* USART3 GPIO config */
      /* Configure USART3 Tx (PB.10) as alternate function push-pull */
      GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
      GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
      GPIO_Init(GPIOA, &GPIO_InitStructure);
      /* Configure USART3 Rx (PB.11) as input floating */
      GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
      GPIO_Init(GPIOB, &GPIO_InitStructure);

      /* USART3 mode config */
      USART_InitStructure.USART_BaudRate = 9600;
      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(USART3, &USART_InitStructure);
      USART_ClearFlag(USART3,USART_FLAG_TC);

      /*使能串口3中断 */
      USART_ITConfig(USART3, USART_IT_RXNE, ENABLE);
      USART_Cmd(USART3, ENABLE);
}
//串口3的优先级
void NVIC_Configuration(void)
{
      NVIC_InitTypeDef NVIC_InitStructure;
      /* Configure the NVIC Preemption Priority Bits */
      NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);

      /* Enable the USARTy Interrupt */
      NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn;
      NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
      NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
      NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
      NVIC_Init(&NVIC_InitStructure);
}
//串口1配置
void USART1_Config(void)
{
            GPIO_InitTypeDef GPIO_InitStructure;
            USART_InitTypeDef USART_InitStructure;

            /* config USART1 clock */
            RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 | RCC_APB2Periph_GPIOA, ENABLE);

            /* USART1 GPIO config */
            /* Configure USART1 Tx (PA.09) as alternate function push-pull */
            GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
            GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
            GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
            GPIO_Init(GPIOA, &GPIO_InitStructure);

            /* Configure USART1 Rx (PA.10) as input floating */
            GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
            GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
            GPIO_Init(GPIOA, &GPIO_InitStructure);

            /* USART1 mode config */
            USART_InitStructure.USART_BaudRate = 9600;
            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(USART1, &USART_InitStructure);
            USART_Cmd(USART1, ENABLE);
}
//串口1的优先级
void NVIC_Configuration1(void)
{
      NVIC_InitTypeDef NVIC_InitStructure;
      /* Configure the NVIC Preemption Priority Bits */
      NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);

      /* Enable the USARTy Interrupt */
      NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
      NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
      NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
      NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
      NVIC_Init(&NVIC_InitStructure);
}
//配置发送函数
void UART3_Send_TxBuffer(uint8_t TxBuffer[],uint8_t len )
{
   uint8_t  i=0;

         for(i=0;i< RXBUFFERSIZE-1;i++)
                  {
      USART_SendData(USART3,TxBuffer);
      while( USART_GetFlagStatus(USART3,USART_FLAG_TC)!= SET);
                        i++;  //加1
            }


}
示波器检测TX发送是没有信号，时钟高电平，而且如果通讯成功接收的信号也会发生