Stm32串口发送字节数据

说明：每发送一次数据，LED等闪烁一下

/*
*说明：
*PA0:KEY1;PA1:KEY2;
*PA2:LED1;PA3:LED2;
*PA9:USART1_TX;PA10:USART1_RX
*/
#include "stm32f10x.h"
#include "stm32f10x_rcc.h"
#include "stm32f10x_gpio.h"
#include "stm32f10x_usart.h"
#include "system_stm32f10x.h"
#include "stdio.h"

#define PUTCHAR_PROTOTYPE int __io_putchar(int ch) 

void RCC_Configuration(void);
void GPIO_Configuration(void); 
void delay_ms(u16 time);
void USART_Configuration(void);

int main()
{
    SystemInit();
    
    RCC_Configuration();
    GPIO_Configuration(); 
    USART_Configuration();
                                                            
    while(1)                                           //循环逐字输出，到结束字'\0'
    {
      printf("\n发送的信息：");
      GPIO_SetBits(GPIOA,GPIO_Pin_2);
      USART_SendData(USART1, '0');                              //发送字符或者：USART1->DR = '0';
      while(USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET){} //等待字符发送完毕
      //while(USART_GetFlagStatus(USART1, USART_FLAG_RXNE) == RESET){} //等待接收完毕
      //变量= (USART_ReceiveData(USART1)); //接受一个字节
      delay_ms(1000);
      GPIO_ResetBits(GPIOA,GPIO_Pin_2);
    }
}

void RCC_Configuration(void)  
{   
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA|RCC_APB2Periph_AFIO,ENABLE);   
} 

void GPIO_Configuration(void)  
{  
  GPIO_InitTypeDef GPIO_InitStructure;  
  
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;             //管脚9
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;       //复用推挽输出
  GPIO_Init(GPIOA, &GPIO_InitStructure);                //TX初始化
  
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;            //管脚10
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;         //上拉输入
  GPIO_Init(GPIOA, &GPIO_InitStructure);                //RX初始化
   
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2|GPIO_Pin_3;//LED GPIO_Pin_All  
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
  GPIO_Init(GPIOA, &GPIO_InitStructure); 
} 

void USART_Configuration(void)//串口初始化函数
{
    //串口参数初始化  
    USART_InitTypeDef USART_InitStructure;               //串口设置恢复默认参数
    //初始化参数设置
    USART_InitStructure.USART_BaudRate = 9600;                  //波特率9600
    USART_InitStructure.USART_WordLength = USART_WordLength_8b; //字长8位
    USART_InitStructure.USART_StopBits = USART_StopBits_1;      //1位停止字节
    USART_InitStructure.USART_Parity = USART_Parity_No;         //无奇偶校验
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//无流控制
    USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;//打开Rx接收和Tx发送功能
    USART_Init(USART1,&USART_InitStructure);                   //初始化
    USART_Cmd(USART1,ENABLE);                                  //启动串口
}

void delay_ms(u16 time)   
{  
  u16 i=0;  
  while(time--)   
  {  
    i=12000;  
    while(i--);  
  }  
} 

int putchar(int c)                                            //putchar函数
{
    if (c == '\n'){putchar('\r');}                                 //将printf的\n变成\r
    USART_SendData(USART1, c);                                   //发送字符
    while(USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET){} //等待发送结束
    return c;                                                      //返回值
}