STM32F103如何实现同时使用串口2、串口3？

一直在用STM32F103做项目，记录一下，如果觉得有用的，也可以参考一下。
步骤

• IO口的初始化；
  
• 串口初始化；
  
• 中断向量初始化。
  
• 中断函数的处理事件
  
  

rs485.c

`/*********************************************************************************************************
** Function name:       RS485_IO_Init
** Descriptions:        usart GPIO 初始化
** input parameters:    void
** output parameters:   void
** Returned value:      void
*********************************************************************************************************/
void RS485_IO_Init(void)
{
                        GPIO_InitTypeDef GPIO_InitStructure;
        RCC_APB2PeriphClockCmd(USART_RCC | RCC_APB2Periph_AFIO,ENABLE);
       
        //串口2配置
        //output
        GPIO_InitStructure.GPIO_Pin = USART2_OUTIO ;
        GPIO_InitStructure.GPIO_Mode =  GPIO_Mode_AF_PP;
        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_10MHz ;
        GPIO_Init(USART2_PORT,&GPIO_InitStructure);
       
       
        //Input
        GPIO_InitStructure.GPIO_Pin = USART2_INIO ;
        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING ;
        GPIO_Init(USART2_PORT,&GPIO_InitStructure);


       
        //485RE
        GPIO_InitStructure.GPIO_Pin = USART2_REIO ;
        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP ;
        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_10MHz ;
        GPIO_Init(USART2_PORT,&GPIO_InitStructure);
       
       
        //串口3配置
        GPIO_InitStructure.GPIO_Pin = USART3_OUTIO ;
        GPIO_InitStructure.GPIO_Mode =  GPIO_Mode_AF_PP;
        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_10MHz ;
        GPIO_Init(USART3_PORT,&GPIO_InitStructure);
       
       
        //Input
        GPIO_InitStructure.GPIO_Pin = USART3_INIO ;
        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING ;
        GPIO_Init(USART3_PORT,&GPIO_InitStructure);


       
        //485RE
        GPIO_InitStructure.GPIO_Pin = USART3_REIO ;
        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP ;
        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_10MHz ;
        GPIO_Init(USART3_PORT,&GPIO_InitStructure);
        RS485_2RE(1);//串口2默认为发送
        RS485_3RE(0);//串口3默认为接收
}


/*********************************************************************************************************
** Function name:       USART_485_Init
** Descriptions:        usart 配置
** input parameters:    void
** output parameters:   void
** Returned value:      void
*********************************************************************************************************/




void USART_485_Init(void)
{
        USART_InitTypeDef USART_InitStruct;
       
        RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3 | RCC_APB1Periph_USART2,ENABLE);
       
        NVIC_InitTypeDef NVIC_InitStructure;
       
        /*设置串口2中断的先占优先级为0，从占优先级为0*/
        NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
        NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
        NVIC_Init(&NVIC_InitStructure);
       
        /*设置串口3中断的先占优先级为0，从占优先级为1*/
        NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn;
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
        NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
        NVIC_Init(&NVIC_InitStructure);
       
       
        /* USART2、USART3设置波特率9600、数据位8bit、停止位1bit、无校验位、无硬件流、接收发送 、中断打开*/
        USART_InitStruct.USART_BaudRate = 9600;
        USART_InitStruct.USART_WordLength = USART_WordLength_8b;
        USART_InitStruct.USART_StopBits = USART_StopBits_1;
        USART_InitStruct.USART_Parity = USART_Parity_No;
        USART_InitStruct.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
        USART_InitStruct.USART_Mode = USART_Mode_Rx | USART_Mode_Tx ;
        USART_Init(USART2,&USART_InitStruct);
        USART_ITConfig(USART2,USART_IT_RXNE,ENABLE);
       
        USART_InitStruct.USART_BaudRate = 9600;
        USART_InitStruct.USART_WordLength = USART_WordLength_8b;
        USART_InitStruct.USART_StopBits = USART_StopBits_1;
        USART_InitStruct.USART_Parity = USART_Parity_No;
        USART_InitStruct.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
        USART_InitStruct.USART_Mode = USART_Mode_Rx | USART_Mode_Tx ;
        USART_Init(USART3,&USART_InitStruct);
        USART_ITConfig(USART3,USART_IT_RXNE,ENABLE);
                       
        /*使能串口2、3*/
        USART_Cmd(USART2,ENABLE);
        USART_Cmd(USART3,ENABLE);
       
}
rs485.h


/**************485使能开关***************/
#define RS485_2RE(x)        x?(GPIOA->ODR |= (1<<4),USART2->CR1 &=~ (3<<2),USART2->CR1 |= (2<<2)):(GPIOA->ODR &=~ (1<<4),USART2->CR1 &=~ (3<<2),USART2->CR1 |= (1<<2))
#define RS485_3RE(x)        x?(GPIOB->ODR |= (1<<12),USART3->CR1 &=~ (3<<2),USART3->CR1 |= (2<<2)):(GPIOB->ODR &=~ (1<<12),USART3->CR1 &=~ (3<<2),USART3->CR1 |= (1<<2))


/*************485IO定义*****************/
#define USART_RCC RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOA
#define USART2_OUTIO GPIO_Pin_2
#define USART2_INIO  GPIO_Pin_3
#define USART2_REIO  GPIO_Pin_4
#define USART2_PORT  GPIOA


#define USART3_OUTIO GPIO_Pin_10
#define USART3_INIO  GPIO_Pin_11
#define USART3_REIO  GPIO_Pin_12
#define USART3_PORT  GPIOB


#ifndef YES
#define YES 1
#endif


#ifndef NO
#define NO 0
#endif
中断处理函数：


void USART2_IRQHandler(void)
{
        Usart2_Send = NO;//发送标志
        if(USART_GetITStatus(USART2,USART_IT_RXNE))
        {
                DRData.usart2_DRdata = USART2->DR;//清中断
                //接下来就是事件处理
        }
        Usart2_Send = YES;
}
void USART3_IRQHandler(void)
{
        Usart3_Send = NO;//发送标志
        if(USART_GetITStatus(USART3,USART_IT_RXNE))
        {
                DRData.usart3_DRdata = USART3->DR;//清中断
                //接下来就是事件处理
        }
        Usart3_Send = YES;
}