stm32串口通信例程

下面是一个简单的STM32串口通信的例程：

#include "stm32f10x.h"

void RCC_Configuration(void)
{
  /* Enable GPIOA clock */
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

  /* Enable USART1 clock */
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
}

void GPIO_Configuration(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;

  /* 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);
}

void USART1_Configuration(void)
{
  USART_InitTypeDef USART_InitStructure;

  USART_InitStructure.USART_BaudRate = 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;

  /* USART configuration */
  USART_Init(USART1, &USART_InitStructure);

  /* Enable USART */
  USART_Cmd(USART1, ENABLE);
}

int main(void)
{
  char data;

  /* System Clocks Configuration */
  RCC_Configuration();

  /* GPIO Configuration */
  GPIO_Configuration();

  /* USART Configuration */
  USART1_Configuration();

  while (1)
  {
    /* Wait until a character is received */
    while (USART_GetFlagStatus(USART1, USART_FLAG_RXNE) == RESET);

    /* Read the received character */
    data = USART_ReceiveData(USART1);

    /* Wait until Tx data register is empty */
    while (USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);

    /* Send the character back */
    USART_SendData(USART1, data);
  }
}

在这个例程中，我们使用了USART1和PA9/PA10引脚进行串口通信。首先，我们需要配置RCC和GPIO，并且使用USART1对其进行配置。然后，在主循环中，我们使用USART_GetFlagStatus()函数来检查接收缓冲区是否有数据。如果有数据，我们使用USART_ReceiveData()函数读取它。然后，我们使用USART_GetFlagStatus()函数来检查传输缓冲区是否为空。如果为空，我们使用USART_SendData()函数将数据发送回主机。