STM32-USART初始化

材料：stm32c8t6最小系统板

步骤：

1.根据数据手册可以看到USART1和USART2的引脚

2.分别初始化USART1和USART2串口，代码如下：

void Usart1_Init(u32 bound)
{
    //先声明GPIO,USART,NVIC三个结构体并开启时钟，后续就可以初始化了
    GPIO_InitTypeDef GPIO_InitStructure;
    USART_InitTypeDef USART_InitStructure;
    NVIC_InitTypeDef NVIC_InitStructure;
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);
	
    //初始化USART1_TX   GPIOA.9
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  
    GPIO_Init(GPIOA, &GPIO_InitStructure);
 
    //初始化USART1_RX   GPIOA.10
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
	  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure); 
 
   //初始化USART
    USART_InitStructure.USART_BaudRate = bound;
    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_Init(USART1, &USART_InitStructure);
    USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);
    USART_Cmd(USART1, ENABLE); 
		
	//初始化Usart1的NVIC
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); 
    NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ; 
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; 
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;  
    NVIC_Init(&NVIC_InitStructure); 
}

void Usart2_Init(u32 bound)
{  
    //同样先声明结构体，打开时钟
    GPIO_InitTypeDef GPIO_InitStructure;
    USART_InitTypeDef USART_InitStructure;
    NVIC_InitTypeDef NVIC_InitStructure;
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE);

    //初始化PA2
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;    
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;    
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    //初始化PA3
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; 
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);  
 
    RCC_APB1PeriphResetCmd(RCC_APB1Periph_USART2,ENABLE);//复位串口2
    RCC_APB1PeriphResetCmd(RCC_APB1Periph_USART2,DISABLE);//停止复位
 
    //初始化NVIC
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); 
    NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn; 
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 3; 
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; 
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; 
    NVIC_Init(&NVIC_InitStructure); 
 
    //初始化USART2
    USART_InitStructure.USART_BaudRate = bound;
    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_Init(USART2, &USART_InitStructure);
    USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);
    USART_Cmd(USART2, ENABLE); 
 
}

void USART3_Init(u32 baud)   
{  
	  //声明结构体
    USART_InitTypeDef USART_InitStructure;  
    NVIC_InitTypeDef NVIC_InitStructure;   
    GPIO_InitTypeDef GPIO_InitStructure;   
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB , ENABLE); 
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3, ENABLE);  
  
    //初始化B11
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;  
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;  
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; 
    GPIO_Init(GPIOB, &GPIO_InitStructure);  
 
	//初始化B10
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;  
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;  
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  
    GPIO_Init(GPIOB, &GPIO_InitStructure);  
 
    //初始化USART3
    USART_InitStructure.USART_BaudRate = baud;  
    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_Init(USART3, &USART_InitStructure); 
    USART_ITConfig(USART3, USART_IT_RXNE, ENABLE);    
    USART_Cmd(USART3, ENABLE); 
 
    //初始化NVIC
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);  
    NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn;   
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2; 
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;  
    NVIC_Init(&NVIC_InitStructure);       
} 

（顺便把USART3也加上了）

（本来打算写一篇stm32有线双机通信的，可是因为刚接触还有不太明白的地方，所以就先初始化一下，剩下的弄会了再写）