使用STM32作串口实现时接收到数据不正常

只看该作者 · 2013-7-17 14:25

用串口助手通过SP485发送数据，但在USART3的数据寄存器中得到的数据不是发送的数据

#include <stm32f10x.h>

#include "usart1.h"
#include <stdarg.h>

void USART3_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB,ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3,ENABLE);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //ÍÆÍìÊä³ö-TX
  GPIO_Init(GPIOB, &GPIO_InitStructure);

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//¸¡¿ÕÊäÈë-RX
  GPIO_Init(GPIOB, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_14;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;//RTX
  GPIO_Init(GPIOB, &GPIO_InitStructure);


/* USART3 ¹¤×÷Ä£Ê½ÅäÖÃ */
USART_InitStructure.USART_BaudRate = 9600; //²¨ÌØÂÊÉèÖÃ£º9600
USART_InitStructure.USART_WordLength = USART_WordLength_8b; //Êý¾ÝÎ»ÊýÉèÖÃ£º8Î»
USART_InitStructure.USART_StopBits = USART_StopBits_1; //Í£Ö¹Î»ÉèÖÃ£º1Î»
USART_InitStructure.USART_Parity = USART_Parity_No ;  //ÊÇ·ñÆæÅ¼Ð£Ñé£ºÎÞ
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None; //Ó²¼þÁ÷¿ØÖÆÄ£Ê½ÉèÖÃ£ºÃ»ÓÐÊ¹ÄÜ
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;//½ÓÊÕÓë·¢ËÍ¶¼Ê¹ÄÜ
//USART_ClearFlag(USART3,USART_FLAG_OR);
USART_Init(USART3, &USART_InitStructure);  //³õÊ¼»¯USART3
USART_Cmd(USART3, ENABLE);// USART3Ê¹ÄÜ

}

/*·¢ËÍÒ»¸ö×Ö½ÚÊý¾Ý*/
void UART3SendByte(unsigned char SendData)
{
GPIO_SetBits(GPIOB,GPIO_Pin_14);
      USART_SendData(USART3,SendData);
      while(USART_GetFlagStatus(USART3, USART_FLAG_TXE) == RESET);
}

/*½ÓÊÕÒ»¸ö×Ö½ÚÊý¾Ý*/
unsigned char UART3GetByte(unsigned char* GetData)

{
GPIO_ResetBits(GPIOB,GPIO_Pin_14);
      if(USART_GetFlagStatus(USART3, USART_FLAG_RXNE) == RESET)
      {  return 0;//Ã»ÓÐÊÕµ½Êý¾Ý
}
      *GetData = USART_ReceiveData(USART3);
      return 1;//ÊÕµ½Êý¾Ý
}
/*½ÓÊÕÒ»¸öÊý¾Ý£¬ÂíÉÏ·µ»Ø½ÓÊÕµ½µÄÕâ¸öÊý¾Ý*/
void UART3Test(void)
{
   unsigned char i = 0;

   while(1)
   {
   while(UART3GetByte(&i))
      {
      UART3SendByte(i);
      }
   }
}