STM32F103 USART2接收数据不正常

lazybonesyang

void MY_USART2_Init()
{
    GPIO_InitTypeDef GPIO_InitStructure;//I/O?ú3?ê??ˉ?á11ì?
    NVIC_InitTypeDef NVIC_InitStructure;//?D??3?ê??ˉ?á11ì?
    USART_InitTypeDef USART_InitStructure;//′??ú3?ê??ˉ?á11ì?  
    
    /* Enable the USART2 Pins Software Remapping */
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA , ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE); 
    
    
    /* Configure USART2 Rx (PA.03) as input floating */
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;    
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
    
    /* Configure USART2 Tx (PA.02) as alternate function push-pull */
/*
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
    */
    /* Enable the USART2 Interrupt */
    NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 3;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);    
    
    USART_InitStructure.USART_BaudRate = 250000;                //ò?°?éè???a9600;
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;//×?3¤?a8??êy?Y??ê?
    USART_InitStructure.USART_StopBits = USART_StopBits_2;     //ò???í￡?1??
    USART_InitStructure.USART_Parity = USART_Parity_No;        //?T????D￡?é??
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//Yá÷????
    USART_InitStructure.USART_Mode = USART_Mode_Rx; //ê?·￠?￡ê?   
    
    USART_Init(USART2, &USART_InitStructure);
    USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);
    //USART_ITConfig(USART2, USART_IT_TXE, ENABLE);
    /* Enable USART2 */
    USART_Cmd(USART2, ENABLE);
}
uint16_t DmxData[20] = {0};
uint16_t DmxHeadFlag = 0;
uint16_t UDR = 0;
uint8_t OpenRecFlag = 0;
void USART2_IRQHandler(void)
{  
static uint8_t dmxaddress = 0;  
if(USART2->SR&(1<<5))//接收到数据
{  
    UDR = USART2->DR;
    USART2->SR &= ~(1<<5);
} 

是想接收DMX512信号的，250K，1个开始位，8个数据位，2个结束位。但一直不正常。收不到数据，求大神搭救，好几天了。

Fliger

怎么又有一个uart2的问题贴？
你用原子开发板还是用自己的板子做的？ 
试试论坛搜索吧 有好多uart2收不到数据的帖子，应该能帮到你

lazybonesyang

回复【2楼】Fliger:
---------------------------------
对比过了，也是根据例子改的，比较奇怪，USART2_SR里面的值有FE出错误还有ORE出错，中断进来了一直无数据。BBR的值是0x00000090，FPCLK是36M，算下来应该就是250K的波特率了，但接收不到数据

lazybonesyang

网上查了下，据说ORE出错要先清掉ORE再读数据。我改了下
uint16_t DmxData[20] = {0};
uint16_t DmxHeadFlag = 0;
uint16_t UDR = 0;
uint8_t OpenRecFlag = 0;
void USART2_IRQHandler(void)
{  
static uint8_t dmxaddress = 0;  
if(USART2->SR&(1<<5))//接收到数据
{  
USART2->SR &= (~((1<<5)|(1<<4)));
UDR = USART2->DR;
DmxHeadFlag =  UDR&0x100;
if(DmxHeadFlag == 0)
{
dmxaddress = 0;
OpenRecFlag = 1;
dmxaddress = 0;
}
else
{
if(OpenRecFlag)
{
DmxData[dmxaddress] = UDR&0xff;
}
if(++dmxaddress > 10)
{
OpenRecFlag = 0;
}
}

}
} 

能接到数据，但数据不对。