dma接收问题，总是接收上一次的数据，不能接收实时数据

lichunfandian · 发表于 2018-3-7 16:00:32

void uart_init(u32 bound)
{
//GPIO¶Ë¿úéèÖÃ
GPIO_InitTypeDef GPIO_InitStructure;
   USART_InitTypeDef USART_InitStructure;
   NVIC_InitTypeDef NVIC_InitStructure;
   DMA_InitTypeDef DMA_InitStructure;

   RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE); //ê1ÄüUSART1￡¬GPIOAê±Öó
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE); //ê1ÄüDMA′«êä
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3|RCC_APB1Periph_USART2,ENABLE);//ê1ÄüUSART2ê±Öó

   USART_DeInit(USART3);  //¸′Î»′®¿ú1
   //USART1_TX PA.9
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10; //PA.9
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //¸′óÃíÆíìêä3ö
GPIO_Init(GPIOB, &GPIO_InitStructure); //3õê¼»ˉPA9

//USART1_RX    PA.10
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//¸¡¿Õêäèë
GPIO_Init(GPIOB, &GPIO_InitStructure);  //3õê¼»ˉPA10

//Usart1 NVIC ÅäÖÃ
NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn;
   NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0 ;//ÇàÕ¼óÅÏè¼¶3
   NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //×óóÅÏè¼¶3
   NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQí¨μàê1Äü
   NVIC_Init(&NVIC_InitStructure); //¸ù¾YÖ¸¶¨μÄ2Îêy3õê¼»ˉVIC¼Ä′æÆ÷

//USART 3õê¼»ˉéèÖÃ
USART_InitStructure.USART_BaudRate = bound;//ò»°ãéèÖÃÎa9600;
USART_InitStructure.USART_WordLength = USART_WordLength_8b;//×Ö3¤Îa8Î»êy¾Y¸ñê½
USART_InitStructure.USART_StopBits = USART_StopBits_1;//ò»¸öí￡Ö1Î»
USART_InitStructure.USART_Parity = USART_Parity_No;//ÎTÆæÅ¼D￡ÑéÎ»
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//ÎTó2¼têy¾Yá÷¿ØÖÆ
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx; //êÕ·￠Ä￡ê½

USART_Init(USART3, &USART_InitStructure); //3õê¼»ˉ′®¿ú
/// USART_ITConfig(USART3, USART_IT_IDLE, ENABLE);//¿aÆô¿ÕÏDÖD¶Ï
//USART_DMACmd(USART3,USART_DMAReq_Rx,ENABLE); //ê1Äü′®¿ú1 DMA½óêÕ
// USART_Cmd(USART3, ENABLE);                   //ê1Äü′®¿ú

//Ïàó|μÄDMAÅäÖÃ
DMA_DeInit(DMA1_Channel3); //½«DMAμÄí¨μà5¼Ä′æÆ÷ÖØéèÎaè±ê¡Öμ  ′®¿ú1¶Ôó|μÄêÇDMAí¨μà5
DMA_InitStructure.DMA_PeripheralBaseAddr = (u32)&USART3->DR;  //DMAíaéèADC»ùμØÖ·
DMA_InitStructure.DMA_MemoryBaseAddr = (u32)DMA_Rece_Buf;  //DMAÄú′æ»ùμØÖ·
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;  //êy¾Y′«êä·½Ïò￡¬′óíaéè¶áè¡·￠Ëíμ½Äú′æ
DMA_InitStructure.DMA_BufferSize = DMA_Rec_Len;  //DMAí¨μàμÄDMA»o′æμÄ′óD¡
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;  //íaéèμØÖ·¼Ä′æÆ÷2»±ä
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;  //Äú′æμØÖ·¼Ä′æÆ÷μYÔö
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;  //êy¾Y¿í¶èÎa8Î»
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte; //êy¾Y¿í¶èÎa8Î»
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;  //1¤×÷ÔúÕy3￡»o′æÄ￡ê½
DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh; //DMAí¨μà xóμóDÖDóÅÏè¼¶
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;  //DMAí¨μàxÃ»óDéèÖÃÎaÄú′æμ½Äú′æ′«êä
DMA_Init(DMA1_Channel3, &DMA_InitStructure);  //¸ù¾YDMA_InitStructÖDÖ¸¶¨μÄ2Îêy3õê¼»ˉDMAμÄí¨μàUSART1_Tx_DMA_ChannelËù±êê¶μÄ¼Ä′æÆ÷

USART_ITConfig(USART3, USART_IT_IDLE, ENABLE);//¿aÆô¿ÕÏDÖD¶Ï
USART_DMACmd(USART3,USART_DMAReq_Rx,ENABLE); //ê1Äü′®¿ú1 DMA½óêÕ
USART_Cmd(USART3, ENABLE);
DMA_Cmd(DMA1_Channel3, ENABLE);  //Õyê½Çy¶ˉDMA′«êä

}

//ÖØDÂ»Ö¸′DMAÖ¸Õë
void MYDMA_Enable(DMA_Channel_TypeDef*DMA_CHx)
{
DMA_Cmd(DMA_CHx, DISABLE );  //1Ø±ÕUSART1 TX DMA1 ËùÖ¸ê¾μÄí¨μà
DMA_SetCurrDataCounter(DMA_CHx,DMA_Rec_Len);//DMAí¨μàμÄDMA»o′æμÄ′óD¡
DMA_Cmd(DMA_CHx, ENABLE);  //ê1ÄüUSART1 TX DMA1 ËùÖ¸ê¾μÄí¨μà
}

//·￠Ëílen¸ö×Ö½ú.
//buf:·￠ËíÇøê×μØÖ·
//len:·￠ËíμÄ×Ö½úêy
void Usart3_Send(u8 *buf,u8 len)
{
u8 t;
    for(t=0;t<len;t++) //Ñ-»··￠Ëíêy¾Y
{
while(USART_GetFlagStatus(USART3, USART_FLAG_TC) == RESET);
USART_SendData(USART3,buf[t]);
}
while(USART_GetFlagStatus(USART3, USART_FLAG_TC) == RESET);
}

//′®¿úÖD¶Ïoˉêy
void USART3_IRQHandler(void)             //′®¿ú1ÖD¶Ï·tÎñ3ìDò
{
#ifdef OS_TICKS_PER_SEC      //èç1ûê±Öó½úÅÄêy¶¨òåáË,ËμÃ÷òaê1óÃucosIIáË.
OSIntEnter();
#endif

if(USART_GetITStatus(USART3, USART_IT_IDLE) != RESET)  //½óêÕÖD¶Ï(½óêÕμ½μÄêy¾Y±ØDëêÇ0x0d 0x0a½áÎ2)
{
MYDMA_Enable(DMA1_Channel3);
   USART_ReceiveData(USART3);//¶áè¡êy¾Y ×￠òa￡oÕa¾ä±ØDëòa￡¬·ñÔò2»Äü1»Çå3yÖD¶Ï±êÖ¾Î»¡￡Îòò22»ÖaμàÎaé¶￡¡
   //Usart1_Rec_Cnt = DMA_Rec_Len-DMA_GetCurrDataCounter(DMA1_Channel3); //Ëã3ö½ó±¾Ö¡êy¾Y3¤¶è
//if(DMA_Rece_Buf[5]==0x01)
//{
// GPIO_SetBits(GPIOD,GPIO_Pin_0);
//delay_ms(1000);
// GPIO_ResetBits(GPIOD,GPIO_Pin_0);
//}
//memset(DMA_Rece_Buf,0,200);
//***********Ö¡êy¾Y′|àíoˉêy************//
//printf ("The lenght:%d\r\n",Usart1_Rec_Cnt);
//printf ("The data:\r\n");
//Usart1_Send(DMA_Rece_Buf,Usart1_Rec_Cnt);
//printf ("\r\nOver! \r\n");
//*************************************//
USART_ClearITPendingBit(USART3, USART_IT_IDLE);       //Çå3yÖD¶Ï±êÖ¾
// MYDMA_Enable(DMA1_Channel3);                //»Ö¸′DMAÖ¸Õë￡¬μè′yÏÂò»′ÎμÄ½óêÕ
// DMA_Cmd(DMA1_Channel3, ENABLE);
   }

#ifdef OS_TICKS_PER_SEC      //èç1ûê±Öó½úÅÄêy¶¨òåáË,ËμÃ÷òaê1óÃucosIIáË.
OSIntExit();
#endif
}
求大神帮忙看下，谢谢