PD5 PD6复用串口2不能发送数据，这是为什么？

huraofeng · 发表于 2017-8-30 20:10:52

void RS485_Init(u32 bound)
{

GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD,ENABLE); //使能GPIOA时钟
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE);//使能USART2时钟

GPIO_PinAFConfig(GPIOD,GPIO_PinSource5,GPIO_AF_USART2); //GPIOA2复用为USART2
GPIO_PinAFConfig(GPIOD,GPIO_PinSource6,GPIO_AF_USART2); //GPIOA3复用为USART2


GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6; //GPIOA2与GPIOA3
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//复用功能
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz; //速度100MHz
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推挽复用输出
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; //上拉
GPIO_Init(GPIOD,&GPIO_InitStructure); //初始化PA2，PA3

USART_InitStructure.USART_BaudRate = bound;//波特率设置
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_Cmd(USART2, ENABLE);  //使能串口 2

USART_ClearFlag(USART2, USART_FLAG_TC);

USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);//开启接受中断

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、

}

int main(void)
{

RS485_Init(9600);

while(1)
{
      USART_SendData( USART2,'W');

}
}