本帖最后由 chenqiang10 于 2018-7-29 20:57 编辑
初始化串口2void RS485_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|RCC_APB2Periph_GPIOG,ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE);
GPIO_InitStructure.GPIO_Pin=GPIO_Pin_2;//PA2(TX)复用推挽输出
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
GPIO_Init(GPIOA,&GPIO_InitStructure);
GPIO_SetBits(GPIOA,GPIO_Pin_2);//默认高电平
GPIO_InitStructure.GPIO_Pin=GPIO_Pin_3;//PA3(RX)输入上拉
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_IPU;
GPIO_Init(GPIOA,&GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin=GPIO_Pin_9;//PG9(RE/DE)通用推挽输出
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_Out_PP;
GPIO_Init(GPIOG,&GPIO_InitStructure);
GPIO_ResetBits(GPIOG,GPIO_Pin_9);//默认接收状态
USART_DeInit(USART2);//复位串口2
USART_InitStructure.USART_BaudRate=RS485_Baudrate;
USART_InitStructure.USART_HardwareFlowControl=USART_HardwareFlowControl_None;
USART_InitStructure.USART_WordLength=USART_WordLength_8b;
USART_InitStructure.USART_StopBits=USART_StopBits_1;
USART_InitStructure.USART_Mode=USART_Mode_Rx|USART_Mode_Tx;//收发模式
switch(RS485_Parity)
{
case 0:USART_InitStructure.USART_Parity=USART_Parity_No;break;//无校验
case 1:USART_InitStructure.USART_Parity=USART_Parity_Odd;break;//奇校验
case 2:USART_InitStructure.USART_Parity=USART_Parity_Even;break;//偶校验
}
USART_Init(USART2,&USART_InitStructure);
USART_ClearITPendingBit(USART2,USART_IT_RXNE);
USART_ITConfig(USART2,USART_IT_RXNE,ENABLE);//使能串口2接收中断
NVIC_InitStructure.NVIC_IRQChannel=USART2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=2;
NVIC_InitStructure.NVIC_IRQChannelSubPriority=2;
NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
NVIC_Init(&NVIC_InitStructure);
USART_Cmd(USART2,ENABLE);//使能串口2
RS485_TX_EN=0;//默认为接收模式
Timer7_Init();//定时器7初始化,用于监视空闲时间
Modbus_RegMap();//Modbus寄存器映射
}
|