Question

我尝试实现USART通信。所以我将我的STM32f1的RX连接到他的TX。我也为这个沟通写了一个程序。此代码由以下组件组成：

RCC配置
GPIO配置
USART配置
发送和接收字符串
发送的字符串与收到的字符串之间的比较
测试通信是否成功=＆gt; LED4打开，否则LED3打开

问题在于所有情况下LED3都会亮起。这意味着数据传输失败。

使用我的IDE（IAR的Embedded Workbench），我编译了这个程序代码：

/* Includes ------------------------------------------------------------------*/
#include "stm32f10x.h"
#include "stm32_eval.h"


/* Private typedef -----------------------------------------------------------*/
typedef enum { FAILED = 0, PASSED = !FAILED} TestStatus;

/* Private define ------------------------------------------------------------*/
#define USARTy                   USART1
#define USARTy_GPIO              GPIOA /* PORT name*/
#define USARTy_CLK               RCC_APB2Periph_USART1
#define USARTy_GPIO_CLK          RCC_APB2Periph_GPIOA
#define USARTy_RxPin             GPIO_Pin_10/* pin Rx name*/ 
#define USARTy_TxPin             GPIO_Pin_9 /* pin Tx name*/

#define USARTz                   USART2
#define USARTz_GPIO              GPIOA/* PORT name*/
#define USARTz_CLK               RCC_APB1Periph_USART2
#define USARTz_GPIO_CLK          RCC_APB2Periph_GPIOA
#define USARTz_RxPin             GPIO_Pin_3/* pin Rx name*/
#define USARTz_TxPin             GPIO_Pin_2/* pin Tx name*/

#define TxBufferSize   (countof(TxBuffer))

/* Private macro -------------------------------------------------------------*/
#define countof(a)   (sizeof(a) / sizeof(*(a)))

/* Private variables ---------------------------------------------------------*/
USART_InitTypeDef USART_InitStructure;
uint8_t TxBuffer[] = "Bufferrr";
uint8_t RxBuffer[8];
__IO uint8_t TxConteur = 0, RxConteur = 0;
volatile TestStatus TransferStatus = FAILED;  

/* Private function prototypes -----------------------------------------------*/
void RCC_Configuration(void);
void GPIO_Configuration(void);
TestStatus Buffercmp(uint8_t* pBuffer1, uint8_t* pBuffer2, uint16_t BufferLength);
__IO uint8_t index = 0;

GPIO_InitTypeDef GPIO_InitStructure;

int main(void)
{
  STM_EVAL_LEDInit(LED1);
  STM_EVAL_LEDInit(LED2);
  STM_EVAL_LEDInit(LED3);
  STM_EVAL_LEDInit(LED4);

/* System Clocks Configuration */
 RCC_Configuration();
/* Configure the GPIO ports */
GPIO_Configuration();

USART_InitStructure.USART_BaudRate = 230400 /*115200*/; 
  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;

  /* Configure USARTy */
  USART_Init(USART1,&USART_InitStructure);

  /* Enable the USARTy */
  USART_Cmd(USART1,ENABLE);

  while(TxConteur < TxBufferSize)
  {  
    /* Send one byte from USARTy to USARTz */
     USART_SendData(USARTy, TxBuffer[TxConteur++]);
    /* Loop until USARTy DR register is empty */ 
    while(USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET)
    {
    }
    /* Store the received byte in RxBuffer */
    RxBuffer[RxConteur++] = USART_ReceiveData(USARTy) & 0xFF;
  }  

  /* Check the received data with the send ones */
  TransferStatus = Buffercmp(TxBuffer, RxBuffer, TxBufferSize);
  /* TransferStatus = FAILED, if the data transmitted from USARTy and 
     received by USARTz are different */
  if (TransferStatus == FAILED)
  {
      STM_EVAL_LEDOn(LED3);

  }
  else 
  {

   STM_EVAL_LEDOn(LED4);
  }

  while (1)
  {
  }
}

void RCC_Configuration(void)
{    

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA , ENABLE);

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 , ENABLE);
   RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC , ENABLE);
}

void GPIO_Configuration(void)
{
  GPIO_InitTypeDef GPIO_InitStructure1,GPIO_InitStructure2;

  /* Configure USARTy Rx as input floating */
  GPIO_InitStructure1.GPIO_Pin =GPIO_Pin_10;
  GPIO_InitStructure1.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure1.GPIO_Mode = GPIO_Mode_IN_FLOATING;
  GPIO_Init(GPIOA, &GPIO_InitStructure1);

  /* Configure USARTy Tx as alternate function push-pull */
  GPIO_InitStructure2.GPIO_Pin =GPIO_Pin_9;
  GPIO_InitStructure2.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure2.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_Init(GPIOA, &GPIO_InitStructure2);
  /* Configure USARTz Tx as alternate function push-pull */


}


TestStatus Buffercmp(uint8_t* pBuffer1, uint8_t* pBuffer2, uint16_t BufferLength)
{
  while(BufferLength--)
  {
    if(*pBuffer1 != *pBuffer2)
    {
      return FAILED;
    }

    pBuffer1++;
    pBuffer2++;
  }

  return PASSED;  
}

Answer 1

就像Hans Passant的评论中所解释的那样，OP正在测试标志USART_FLAG_TC（传输完成）而不是标志USART_FLAG_RXNE（RX缓冲区非空）。

USART与STM32f1xx通信

1 个答案: