初始化函数

void uart1_init(u32 bound){
   //GPIO端口设置
    GPIO_InitTypeDef GPIO_InitStructure;
	USART_InitTypeDef USART_InitStructure;
	NVIC_InitTypeDef NVIC_InitStructure;
	
	RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA,ENABLE); //使能GPIOA时钟
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1,ENABLE);//使能USART1时钟
 
	//串口1对应引脚复用映射
	GPIO_PinAFConfig(GPIOA,GPIO_PinSource9,GPIO_AF_USART1); //GPIOA9复用为USART1
	GPIO_PinAFConfig(GPIOA,GPIO_PinSource10,GPIO_AF_USART1); //GPIOA10复用为USART1
	
	//USART1端口配置
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9 | GPIO_Pin_10; //GPIOA9与GPIOA10
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//复用功能
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;	//速度50MHz
	GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推挽复用输出
	GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; //上拉
	GPIO_Init(GPIOA,&GPIO_InitStructure); //初始化PA9，PA10

   //USART1 初始化设置
	USART_InitStructure.USART_BaudRate = bound;//波特率设置
	USART_InitStructure.USART_WordLength = USART_WordLength_8b;//字长为8位数据格式
	USART_InitStructure.USART_StopBits = USART_StopBits_1;//一个停止位
	USART_InitStructure.USART_Parity = USART_Parity_No;//无奇偶校验位
	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//无硬件数据流控制
	USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;	//收发模式
    USART_Init(USART1, &USART_InitStructure); //初始化串口1
	
    USART_Cmd(USART1, ENABLE);  //使能串口1 
	
	//USART_ClearFlag(USART1, USART_FLAG_TC);
	
#if EN_USART1_RX	
	USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);//开启相关中断

	//Usart1 NVIC 配置
    NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;//串口1中断通道
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=2;//抢占优先级3
	NVIC_InitStructure.NVIC_IRQChannelSubPriority =3;		//子优先级3
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;			//IRQ通道使能
	NVIC_Init(&NVIC_InitStructure);	//根据指定的参数初始化VIC寄存器、

#endif
	
}

void uart2_init(u32 bound){
   //GPIO端口设置
    GPIO_InitTypeDef GPIO_InitStructure;
	USART_InitTypeDef USART_InitStructure;
	NVIC_InitTypeDef NVIC_InitStructure;
	
	RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD,ENABLE); //使能GPIOA时钟
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE);//使能USART1时钟
 
	//串口1对应引脚复用映射
	GPIO_PinAFConfig(GPIOD,GPIO_PinSource5,GPIO_AF_USART2); //GPIOA9复用为USART1
	GPIO_PinAFConfig(GPIOD,GPIO_PinSource6,GPIO_AF_USART2); //GPIOA10复用为USART1
	
	//USART1端口配置
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6; //GPIOA9与GPIOA10
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//复用功能
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;	//速度50MHz
	GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推挽复用输出
	GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; //上拉
	GPIO_Init(GPIOD,&GPIO_InitStructure); //初始化PA9，PA10

   //USART1 初始化设置
	USART_InitStructure.USART_BaudRate = bound;//波特率设置
	USART_InitStructure.USART_WordLength = USART_WordLength_8b;//字长为8位数据格式
	USART_InitStructure.USART_StopBits = USART_StopBits_1;//一个停止位
	USART_InitStructure.USART_Parity = USART_Parity_No;//无奇偶校验位
	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//无硬件数据流控制
	USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;	//收发模式
    USART_Init(USART2, &USART_InitStructure); //初始化串口1
	
    USART_Cmd(USART2, ENABLE);  //使能串口1 
	
	USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);//开启相关中断
 
	//Usart1 NVIC 配置
    NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;//串口1中断通道
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=1;//抢占优先级3
	NVIC_InitStructure.NVIC_IRQChannelSubPriority =1;		//子优先级3
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;			//IRQ通道使能
	NVIC_Init(&NVIC_InitStructure);	//根据指定的参数初始化VIC寄存器、
 }
void uart3_init(u32 bound){
   //GPIO端口设置
	GPIO_InitTypeDef GPIO_InitStructure;
	USART_InitTypeDef USART_InitStructure;
	NVIC_InitTypeDef NVIC_InitStructure;
	
	RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB,ENABLE); //使能GPIOB时钟
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3,ENABLE);//使能USART3时钟
 
	//串口3对应引脚复用映射
	GPIO_PinAFConfig(GPIOB,GPIO_PinSource11,GPIO_AF_USART3); //GPIOA10复用为USART3
	GPIO_PinAFConfig(GPIOB,GPIO_PinSource10,GPIO_AF_USART3); //GPIOA11复用为USART3
	
	//USART3端口配置
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11 | GPIO_Pin_10; //GPIOA11与GPIOA10
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//复用功能
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;	//速度50MHz
	GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推挽复用输出
	GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; //上拉
	GPIO_Init(GPIOB,&GPIO_InitStructure); //初始化
 
   //USART3 初始化设置
	USART_InitStructure.USART_BaudRate = bound;//波特率设置
	USART_InitStructure.USART_WordLength = USART_WordLength_8b;//字长为8位数据格式
	USART_InitStructure.USART_StopBits = USART_StopBits_1;//一个停止位
	USART_InitStructure.USART_Parity = USART_Parity_No;//无奇偶校验位
	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//无硬件数据流控制
	USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;	//收发模式
	USART_Init(USART3, &USART_InitStructure); //初始化串口1
		
	USART_Cmd(USART3, ENABLE);  //使能串口3
	
	//USART_ClearFlag(USART1, USART_FLAG_TC);
	
#if EN_USART1_RX	
	USART_ITConfig(USART3, USART_IT_RXNE, ENABLE);//开启相关中断
 
	//Usart1 NVIC 配置
    NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn;//串口1中断通道
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=1;//抢占优先级3
	NVIC_InitStructure.NVIC_IRQChannelSubPriority =1;		//子优先级3
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;			//IRQ通道使能
	NVIC_Init(&NVIC_InitStructure);	//根据指定的参数初始化VIC寄存器、
 
#endif
	
}

void uart4_init(u32 bound){
   //GPIO端口设置
	GPIO_InitTypeDef GPIO_InitStructure;
	USART_InitTypeDef USART_InitStructure;
	NVIC_InitTypeDef NVIC_InitStructure;
	
	RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC,ENABLE); //使能GPIOB时钟
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_UART4,ENABLE);//使能USART3时钟
 
	//串口3对应引脚复用映射
	GPIO_PinAFConfig(GPIOC,GPIO_PinSource11,GPIO_AF_UART4); //GPIOA10复用为USART3
	GPIO_PinAFConfig(GPIOC,GPIO_PinSource10,GPIO_AF_UART4); //GPIOA11复用为USART3
	
	//USART3端口配置
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11 | GPIO_Pin_10; //GPIOA11与GPIOA10
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//复用功能
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;	//速度50MHz
	GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推挽复用输出
	GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; //上拉
	GPIO_Init(GPIOC,&GPIO_InitStructure); //初始化
 
   //USART3 初始化设置
	USART_InitStructure.USART_BaudRate = bound;//波特率设置
	USART_InitStructure.USART_WordLength = USART_WordLength_8b;//字长为8位数据格式
	USART_InitStructure.USART_StopBits = USART_StopBits_1;//一个停止位
	USART_InitStructure.USART_Parity = USART_Parity_No;//无奇偶校验位
	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//无硬件数据流控制
	USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;	//收发模式
	USART_Init(UART4, &USART_InitStructure); //初始化串口1
		
	USART_Cmd(UART4, ENABLE);  //使能串口3
	
	//USART_ClearFlag(USART1, USART_FLAG_TC);
	
#if EN_USART1_RX	
	USART_ITConfig(UART4, USART_IT_RXNE, ENABLE);//开启相关中断
 
	//Usart1 NVIC 配置
    NVIC_InitStructure.NVIC_IRQChannel = UART4_IRQn;//串口1中断通道
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=2;//抢占优先级3
	NVIC_InitStructure.NVIC_IRQChannelSubPriority =3;		//子优先级3
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;			//IRQ通道使能
	NVIC_Init(&NVIC_InitStructure);	//根据指定的参数初始化VIC寄存器、
 
#endif
	
}

中断服务函数

void USART2_IRQHandler(void)
{
	uint8_t ReBuff;
	if(USART_GetITStatus(USART2,USART_IT_RXNE)!=RESET)
	{		
		ReBuff= USART_ReceiveData(USART2);
		USART_SendData (USART2,ReBuff);//发送数据函数
	}
}


void USART3_IRQHandler(void)
{
	uint8_t ReBuff;
	if(USART_GetITStatus(USART3,USART_IT_RXNE)!=RESET)
	{		
		ReBuff= USART_ReceiveData(USART3);
		USART_SendData (USART3,ReBuff);//发送数据函数
	}
}

void UART4_IRQHandler(void)
{
	uint8_t ReBuff;
	if(USART_GetITStatus(UART4,USART_IT_RXNE)!=RESET)
	{		
		ReBuff= USART_ReceiveData(UART4);
		USART_SendData (UART4,ReBuff);//发送数据函数
	}
}