STM32F103系列串口3中断回显

//串口3配置
static void Usart3GpioInit(void)
{
    GPIO_InitTypeDef    GPIO_InitStructure;
    //使能GPIOB时钟
    RCC_APB2PeriphClockCmd(USART3_GPIO_CLK,ENABLE);
    
    //TX 复用推挽输出
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Pin = USART3_TX_GPIO_PIN;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(USART3_GPIO_PORT,&GPIO_InitStructure);
    //RX 浮空输入
    GPIO_InitStructure.GPIO_Pin = USART3_RX_GPIO_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_Init(USART3_GPIO_PORT,&GPIO_InitStructure);
    
}

static void Usart3Config(void)
{
    USART_InitTypeDef         USART_InitStructure;
    
    RCC_APB1PeriphClockCmd(USART3_CLK,ENABLE);
    //USART1 初始化设置
    USART_InitStructure.USART_BaudRate = USART3_BAUDRATE;                            //波特率
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;                        //8位数据位
    USART_InitStructure.USART_StopBits = USART_StopBits_1;                            //一个停止位
    USART_InitStructure.USART_Parity = USART_Parity_No;                                //无奇偶校验
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;    //无硬件流控制
    USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;                    //收发模式
            
    USART_Init(USART3,&USART_InitStructure);        //初始化串口
    USART_ITConfig(USART3,USART_IT_RXNE,ENABLE);    //开启串口中断
    USART_Cmd(USART3,ENABLE);                        //使能串口
    
}

static void Usart3NvicInit(void)
{
    NVIC_InitTypeDef         NVIC_InitStructure;
    //usart1 NVIC 配置
    NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn;            
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;    //抢占优先级1
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;            //子优先级3
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;                //IRQ通道使能
    NVIC_Init(&NVIC_InitStructure);

}

void Usart3Init(void)
{
    Usart3GpioInit();
    Usart3NvicInit();
    Usart3Config();
        
}


//重定向输出，使printf能输出在PC端
int fputc(int ch, FILE *f)
{
    while((USART3->SR&0x40)==0);//循环发送，直到发送完成
    USART3->DR = (u8)ch;
    return ch;
}
//中断读取到什么数据就返回什么数据
void USART3_IRQHandler(void)
{
    uint16_t temp;
    if(USART_GetITStatus(USART3,USART_IT_RXNE)!=RESET)
    {    
        temp = USART_ReceiveData(USART3);
        USART_SendData(USART3,temp);
    }
}

#ifndef _USART_H_
#define _USART_H_

#include "stm32f10x.h"
#include <stdio.h>


//串口3配置
#define        USART3_CLK                        RCC_APB1Periph_USART3
#define        USART3_GPIO_CLK                    RCC_APB2Periph_GPIOB
#define        USART3_BAUDRATE                    115200

                    
#define        USART3_TX_GPIO_PIN                GPIO_Pin_10                
#define        USART3_RX_GPIO_PIN                GPIO_Pin_11
#define        USART3_GPIO_PORT                GPIOB

#define     USART3_IRQn                        USART3_IRQn
#define        USART3_IRQHandler                USART3_IRQHandler


void Usart3Init(void);

#endif