usart2 重映射

Posted 2021-01-07 uestcman

今天拾起闲置很久的灰机，测试发现nrf2401坏掉，重新淘宝。还发现机上搭载的usart1坏掉，换成usart2，发现端口被电机占用，重映射到PD5，PD6

关键是后面两句不要忘记了

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD, ENABLE);   //使能USART2，GPIOD时钟
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);
    GPIO_PinRemapConfig(GPIO_Remap_USART2, ENABLE);

修改后的原子printf代码usart.c

void uart_init(u32 bound){
  //GPIO端口设置
    GPIO_InitTypeDef GPIO_InitStructure;
    USART_InitTypeDef USART_InitStructure;
    NVIC_InitTypeDef NVIC_InitStructure;
    
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD, ENABLE);   //使能USART2，GPIOD时钟
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);
    GPIO_PinRemapConfig(GPIO_Remap_USART2, ENABLE);

  
    //USART2_TX   GPIOD5
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5; //PD5
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;   //复用推挽输出
  GPIO_Init(GPIOD, &GPIO_InitStructure);//初始化GPIOD5
   
  //USART2_RX     GPIOD6初始化
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;//PD6
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//浮空输入
  GPIO_Init(GPIOD, &GPIO_InitStructure);//初始化GPIOD6

  //Usart2 NVIC 配置
  NVIC_InitStructure.NVIC_IRQChannel = USART2_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;//串口波特率
    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2
  USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);//开启串口接受中断
  USART_Cmd(USART2, ENABLE);                    //使能串口2 

}

void USART2_IRQHandler(void)                    //串口2中断服务程序
    {
    u8 Res;
#if SYSTEM_SUPPORT_OS       //如果SYSTEM_SUPPORT_OS为真，则需要支持OS.
    OSIntEnter();    
#endif
    if(USART_GetITStatus(USART2, USART_IT_RXNE) != RESET)  //接收中断(接收到的数据必须是0x0d 0x0a结尾)
        {
        Res =USART_ReceiveData(USART2); //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      
                    }        
                }
            }            
     }