void uart_init(u32 bound){
    //GPIO端口设置
    GPIO_InitTypeDef GPIO_InitStructure;
	USART_InitTypeDef USART_InitStructure;
	NVIC_InitTypeDef NVIC_InitStructure;
	 
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA, ENABLE);	//使能USART1，GPIOA时钟
 	USART_DeInit(USART1);  //复位串口1
	 //USART1_TX   PA.9
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; //PA.9
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;	//复用推挽输出
    GPIO_Init(GPIOA, &GPIO_InitStructure); //初始化PA9
   
    //USART1_RX	  PA.10
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//浮空输入
    GPIO_Init(GPIOA, &GPIO_InitStructure);  //初始化PA10

   //Usart1 NVIC 配置

    NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//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
  
   //USART 初始化设置

	USART_InitStructure.USART_BaudRate = bound;//一般设置为9600;
	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
    USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);//开启中断
    USART_Cmd(USART1, ENABLE);                    //使能串口 

}

中断服务程序

void USART1_IRQHandler(void)                	//串口1中断服务程序
	{
	u8 Res;
#ifdef OS_TICKS_PER_SEC	 	//如果时钟节拍数定义了,说明要使用ucosII了.
	OSIntEnter();    
#endif
	if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)  //接收中断(接收到的数据必须是0x0d 0x0a结尾)
		{
		Res =USART_ReceiveData(USART1);//(USART1->DR);	//读取接收到的数据	
		if((USART_RX_STA&0x8000)==0)//接收未完成
			{
			if(USART_RX_STA&0x4000)//接收到了0x0d
				{
				if(Res!=0x0a)USART_RX_STA=0;//接收错误,重新开始
				else USART_RX_STA|=0x8000;	//接收完成了 
				}
			else //还没收到0X0D
				{	
				if(Res==0x0d)USART_RX_STA|=0x4000;
				else
					{
					USART_RX_BUF[USART_RX_STA&0X3FFF]=Res ;
					USART_RX_STA++;
					if(USART_RX_STA>(USART_REC_LEN-1))USART_RX_STA=0;//接收数据错误,重新开始接收	  
					}		 
				}  	
			}  
				 
     }

主函数

int main(void)
 {	   	 
	delay_init();	    	 //延时函数初始化	  
	NVIC_Configuration(); 	 //设置NVIC中断分组2:2位抢占优先级，2位响应优先级
	uart_init(9600);	  	 //串口初始化为9600
	HMISendstart();          //为确保串口HMI正常通信
	{ 
		HMISends("cls RED");  //发送串口指令
		HMISendb(0xff);		  //发送结束符 0XFF 0XFF 0XFF
		delay_ms(1000);
    	HMISends("cls GREEN");
		HMISendb(0xff);
    	delay_ms(1000);
    	HMISends("cls BLUE");
		HMISendb(0xff);
		delay_ms(1000);
		HMISends("cls BLACK");
		HMISendb(0xff); 
		delay_ms(1000);
		HMISends("page 4");
		HMISendb(0xff);
		HMISends("t0.txt=\"春风不度玉门关\"");
		HMISendb(0xff);	
	}
	while(1);
}

字符串发送函数

void HMISends(char *buf1)		  //字符串发送函数
{
	u8 i=0;
	while(1)
	{
	 if(buf1[i]!=0)
	 	{
			USART_SendData(USART1,buf1[i]);  //发送一个字节
			while(USART_GetFlagStatus(USART1,USART_FLAG_TXE)==RESET){};//等待发送结束
		 	i++;
		}
	 else 
	 return ;

		}
	}```
字节发送函数

```c
void HMISendb(u8 k)		         //字节发送函数
{		 
	u8 i;
	 for(i=0;i<3;i++)
	 {
	 if(k!=0)
	 	{
			USART_SendData(USART1,k);  //发送一个字节
			while(USART_GetFlagStatus(USART1,USART_FLAG_TXE)==RESET){};//等待发送结束
		}
	 else 
	 return ;

	 } 
}