STM32串口中断实例二

int main(void) 
{
    uint8_t a=0;//LED高低电压控制

    /* System Clocks Configuration */
    RCC_Configuration();                                              //系统时钟设置
    /*嵌套向量中断控制器
        说明了USART1抢占优先级级别0(最多1位) ,和子优先级级别0(最多7位) */
    NVIC_Configuration();                                              //中断源配置
    /*对控制LED指示灯的IO口进行了初始化,将端口配置为推挽上拉输出,口线速度为50Mhz。PA9,PA10端口复用为串口1的TX,RX。
    在配置某个口线时,首先应对它所在的端口的时钟进行使能。否则无法配置成功,由于用到了端口B, 因此要对这个端口的时钟
    进行使能,同时由于用到复用IO口功能用于配置串口。因此还要使能AFIO(复用功能IO)时钟。*/
    GPIO_Configuration();                                              //端口初始化
    USART_Config(USART1);                                              //串口1初始化

    while (1)
    {
        if(rec_f == 1) 
        {    
            //判断是否收到一帧有效数据                                             
            rec_f = 0;

            for(i=0; i<sizeof(TxBuffer1); i++) //发送字符串
            {
                USART_SendChar(USART1,TxBuffer1[i]);
                Delay(0x0000ff0);
            }
            /*for(i=0;i<TxCounter1;i++)//发送字符串
            {
                USART_SendChar(USART1,RxBuffer1[i]);
            } */
            if(a==0) 
            {
                GPIO_SetBits(GPIOD, GPIO_Pin_2);    //LED1  明暗闪烁
                a=1;
            }
            else 
            {
                GPIO_ResetBits(GPIOD, GPIO_Pin_2);
                a=0;
            }
        }
    }
}

main函数如上。

相关变量

uint8_t TxBuffer1[] = "USART Interrupt Example: This is USART1 DEMO";
uint8_t RxBuffer1[], rec_f, tx_flag, i;

__IO uint8_t TxCounter1 = 0x00;
__IO uint8_t RxCounter1 = 0x00;

uint32_t Rec_Len;

串口中断函数配置如下所示:

//--------------------------------------------------------------------------------------
void USART_SendChar(USART_TypeDef* USARTx,uint8_t data) 
{
    USART_SendData(USARTx,data);
    while(USART_GetFlagStatus(USARTx,USART_FLAG_TC)==RESET);
}
//--------------------------------------------------------------------------------------
void USART_Config(USART_TypeDef* USARTx) 
{
    USART_InitStructure.USART_BaudRate = 19200;                        //速率19200bps
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;        //数据位8位
    USART_InitStructure.USART_StopBits = USART_StopBits_1;            //停止位1位
    USART_InitStructure.USART_Parity = USART_Parity_No;                //无校验位
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;   //无硬件流控
    USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;                    //收发模式

    /* Configure USARTx */
    USART_Init(USARTx, &USART_InitStructure);                            //配置串口参数函数


    /* Enable USARTx Receive and Transmit interrupts */
    USART_ITConfig(USARTx, USART_IT_RXNE, ENABLE);          //使能接收中断
    USART_ITConfig(USARTx, USART_IT_TXE, ENABLE);            //使能发送缓冲空中断

    /* Enable the USARTx */
    USART_Cmd(USARTx, ENABLE);
}
//--------------------------------------------------------------------------------------
void Delay(__IO uint32_t nCount) 
{
    for(; nCount!=0; nCount--);
}
/*--------------------------------------------------------------------------------------
系统时钟配置为72MHZ+外设时钟配置*/
void RCC_Configuration(void) 
{
    SystemInit();
    RCC_APB2PeriphClockCmd( RCC_APB2Periph_USART1 | RCC_APB2Periph_GPIOD |RCC_APB2Periph_GPIOA, ENABLE);
}
//--------------------------------------------------------------------------------------
void GPIO_Configuration(void) 
{
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;                     //LED1控制--PD2
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;             //推挽输出
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOD, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;                      //USART1 TX
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;             //复用推挽输出
    GPIO_Init(GPIOA, &GPIO_InitStructure);                     //A端口

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;                  //USART1 RX
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;        //复用开漏输入
    GPIO_Init(GPIOA, &GPIO_InitStructure);                      //A端口
}
//--------------------------------------------------------------------------------------
void NVIC_Configuration(void) 
{
    /*  结构声明*/
    NVIC_InitTypeDef NVIC_InitStructure;

    /* Configure the NVIC Preemption Priority Bits */
    /* Configure one bit for preemption priority */
    /* 优先级组 说明了抢占优先级所用的位数,和子优先级所用的位数   在这里是1, 7 */
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);

    NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;                     //设置串口1中断
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;             //抢占优先级 0
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;                //子优先级为0
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;                    //使能
    NVIC_Init(&NVIC_InitStructure);
}

在中断服务函数中编写usart函数。

//串口1 中断服务程序
void USART1_IRQHandler(void)      
{
    unsigned int i;
    
    //判断读寄存器是否非空
    if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)       
    {
        //将读寄存器的数据缓存到接收缓冲区里
        RxBuffer1[RxCounter1++] = USART_ReceiveData(USART1);   

        //判断结束标志是否是0x0d 0x0a
        if(RxBuffer1[RxCounter1-2] == 0x0d && RxBuffer1[RxCounter1-1] == 0x0a)     
        {
            for(i=0; i< RxCounter1; i++) 
                TxBuffer1[i] = RxBuffer1[i];          //将接收缓冲器的数据转到发送缓冲区,准备转发
            
            //接收成功标志
            rec_f = 1;            
            
            //发送缓冲区结束符
            TxBuffer1[RxCounter1] = 0;                                             
            TxCounter1 = RxCounter1;
            RxCounter1 = 0;
        }
    }

    //这段是为了避免STM32 USART 第一个字节发不出去的BUG
    if(USART_GetITStatus(USART1, USART_IT_TXE) != RESET)                   
    {
        //禁止发缓冲器空中断,
        USART_ITConfig(USART1, USART_IT_TXE, DISABLE);                         
    }

}

运行结果如下,在发送去不填写任何字符,直接发送,显示RT Interrupt Example: This is USART1 DEMO,说明前三个字符已经被占用替换了。

试验平台alienteck mini stm32V1.9 stm32f103rbt6

posted @ 2018-10-03 14:32  wdliming  阅读(3456)  评论(0编辑  收藏  举报