请问STM32F0串口DMA收发数据怎么实现？

回帖（1）

华农武

2021-11-18 09:20:07

这里用的库函数版本，芯片型号为stm32f030c8t6.在用到串口DMA时，要按以下几个步骤进行。 1.确定使用的串口号，这里，我用的是usart2,对应复用的引脚是PA2,PA3。再根据数据手册查询其对应DMA通道。

对应使用是DMA1_CH4（USART2_TX）与DMA1_CH5（USART2_RX）

2.先进行串口初始化配置

void USART2_Init()
{
GPIO_InitTypeDef  GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef  NVIC_InitStructure;

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);

GPIO_PinAFConfig(GPIOA, GPIO_PinSource2, GPIO_AF_1); //Tx
GPIO_PinAFConfig(GPIOA, GPIO_PinSource3, GPIO_AF_1); //Rx
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2 |GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_UP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
//配置串口中断优先级
NVIC_InitStructure.NVIC_IRQChannel                = USART2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPriority          = 2;
NVIC_InitStructure.NVIC_IRQChannelCmd             = ENABLE;
NVIC_Init(&NVIC_InitStructure);

USART_DeInit(USART2);
USART_InitStructure.USART_BaudRate          = bound;                            //波特率
USART_InitStructure.USART_WordLength       = USART_WordLength_8b;             //数据长度8
USART_InitStructure.USART_StopBits          = USART_StopBits_1;                //1个停止位
USART_InitStructure.USART_Parity             = USART_Parity_No;                   //无奇偶校验
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;    //无硬件流控制
USART_InitStructure.USART_Mode             = USART_Mode_Tx | USART_Mode_Rx;
USART_Init(USART2, &USART_InitStructure);

USART_ITConfig(USART2, USART_IT_IDLE, ENABLE);//使能串口空闲中断
USART_ClearITPendingBit(USART2, USART_IT_IDLE);//清除串口空闲中断标志位
USART_Cmd(USART2, ENABLE);//使能串口

}

3.再配置DMA初始化

```c
u8 DMA_Rx[Temp_BufSize_LEN] = {0};
u8 DMA_Tx[Temp_BufSize_LEN] = {0};

void DMA1_Config(void)

{

DMA_InitTypeDef DMA_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1,ENABLE);

   /*****DMA发送配置 Memory->Peripheral *****************/
DMA_DeInit(DMA1_Channel4);          //将DMA1_Channel4信道寄存器初始化为默认的重置值。
DMA_InitStructure.DMA_BufferSize = DMA1_MEM_LEN_RX;//设置DMA1的Buffer缓冲区大小，DMA1_MEM_LEN_RX为自定义的变量
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;    //关闭内存到内存
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;    //正常模式
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;  //内存到外设
DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh; //优先级非常高
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; //内存地址递增
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&USART2->TDR; //设置外设接收地址
DMA_InitStructure.DMA_PeripheralInc =  DMA_PeripheralInc_Disable; //外设地址不变
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;    //设置内存数据长度以Byte为单位
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)DMA_Tx;          //设置内存发送地址，DMA_Tx为自定义变量
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte; //设置外设数据长度以Byte为单位
DMA_Init(DMA1_Channel4,&DMA_InitStructure);

DMA_ClearITPendingBit(DMA1_IT_TC4);  //清除DMA_ch4传输完成中断标志
DMA_ITConfig(DMA1_Channel4,DMA_IT_TC,ENABLE); //使能DMA1_CH4传输完成中断
USART_DMACmd(USART2,USART_DMAReq_Tx,ENABLE); //使能串口与DMA发送关联

/*****DMA接收配置 Peripheral->Memory*****************/
DMA_DeInit(DMA1_Channel5);
DMA_InitStructure.DMA_BufferSize = DMA1_MEM_LEN_RX;
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&USART2->RDR;
DMA_InitStructure.DMA_PeripheralInc =  DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)DMA_Rx;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
DMA_Init(DMA1_Channel5,&DMA_InitStructure);

DMA_ClearITPendingBit(DMA1_IT_TC5);
DMA_ITConfig(DMA1_Channel5,DMA_IT_TC,ENABLE);
USART_DMACmd(USART2,USART_DMAReq_Rx,ENABLE);
DMA_Cmd(DMA1_Channel5,ENABLE);  //使能DMA通道5

NVIC_InitStructure.NVIC_IRQChannel = DMA1_Channel4_5_IRQn;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_InitStructure.NVIC_IRQChannelPriority = 1;

NVIC_Init(&NVIC_InitStructure);

}
//注意：DMA初始化没有使能DMA_CH4,我们只需在要发送数据时使能即可

4.用DMA接收数据

void USART2_IRQHandler(void)
{
u32 id = 0;
u8 FIFO_Level = 0,i = 0;
uint16_t Temp_Len=0;
//OverRun Error处理
if(USART_GetFlagStatus(USART2, USART_FLAG_ORE) != RESET)
{
   USART_ReceiveData(USART2);
   USART_ClearFlag(USART2, USART_FLAG_ORE);
}
//接收空闲中断处理
if(USART_GetITStatus(USART2, USART_IT_IDLE) != RESET)
{
   USART_ClearITPendingBit(USART2, USART_IT_IDLE); //清除中断标志位
   DMA_Cmd(DMA1_Channel5, DISABLE);
   Temp_Len= DMA1_MEM_LEN_RX - DMA_GetCurrDataCounter(DMA1_Channel5);//获得传输的数据个数
   DMA_SetCurrDataCounter(DMA1_Channel5, DMA1_MEM_LEN_RX);
   DMA_Cmd(DMA1_Channel5, ENABLE);

   //此部分为自定义的传输协议
   id = ((u32)DMA_Rx[0] << 24) | ((u32)DMA_Rx[1] << 16) | ((u32)DMA_Rx[2] << 8) | (u32)DMA_Rx[3];
   if(((id >> 13) & 0xff) != 0xff && ((id >> 13) & 0xff) != MY485_deviceinf[14])
      return;
   FIFO_Level = RS485_SetRxFifoFillLevel(RS485_FIFO.RS485_RCE);
   if(FIFO_Level > 3)
      return;
   RS485_FIFO.FIFO_RxBuff_DLen[FIFO_Level-1] = Temp_Len;
   for(i = 0; i < RS485_FIFO.FIFO_RxBuff_DLen[FIFO_Level-1]; i++)
      RS485_FIFO.RS485_FIFO_RXBUFF[FIFO_Level-1] = DMA_Rx;

   memset(&DMA_Rx, 0, sizeof(DMA_Rx)); //将DMA中Buffer清空
}

}

5.用DMA发送数据

void DMA_Enable_TX(DMA_Channel_TypeDef *DMA_CHx, u8 len)
{
RS485_TX_Enable(); //由于用的是rs485，故需先置高bussy信号
   DMA_Cmd(DMA_CHx, ENABLE);  //使能通道
//DMA_Cmd(DMA_CHx, DISABLE);
//DMA_SetCurrDataCounter(DMA_CHx, len);
//DMA_Cmd(DMA_CHx, ENABLE);
}

int main(void)
{
int i = 0;

delay_init()
USART2_Init();
RS485_Busy_init();
DMA1_Config();

while(1)
{
DMA_Enable_TX(DMA1_Channel4,DMA1_MEM_LEN_RX);
DMA_Tx[0]='H'; //例如发送H字母

}
}

以上是我对串口DMA的使用理解，希望能帮助到大家，谢谢观看。
这里用的库函数版本，芯片型号为stm32f030c8t6.在用到串口DMA时，要按以下几个步骤进行。 1.确定使用的串口号，这里，我用的是usart2,对应复用的引脚是PA2,PA3。再根据数据手册查询其对应DMA通道。

对应使用是DMA1_CH4（USART2_TX）与DMA1_CH5（USART2_RX）

2.先进行串口初始化配置

void USART2_Init()
{
GPIO_InitTypeDef  GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef  NVIC_InitStructure;

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);

GPIO_PinAFConfig(GPIOA, GPIO_PinSource2, GPIO_AF_1); //Tx
GPIO_PinAFConfig(GPIOA, GPIO_PinSource3, GPIO_AF_1); //Rx
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2 |GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_UP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
//配置串口中断优先级
NVIC_InitStructure.NVIC_IRQChannel                = USART2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPriority          = 2;
NVIC_InitStructure.NVIC_IRQChannelCmd             = ENABLE;
NVIC_Init(&NVIC_InitStructure);

USART_DeInit(USART2);
USART_InitStructure.USART_BaudRate          = bound;                            //波特率
USART_InitStructure.USART_WordLength       = USART_WordLength_8b;             //数据长度8
USART_InitStructure.USART_StopBits          = USART_StopBits_1;                //1个停止位
USART_InitStructure.USART_Parity             = USART_Parity_No;                   //无奇偶校验
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;    //无硬件流控制
USART_InitStructure.USART_Mode             = USART_Mode_Tx | USART_Mode_Rx;
USART_Init(USART2, &USART_InitStructure);

USART_ITConfig(USART2, USART_IT_IDLE, ENABLE);//使能串口空闲中断
USART_ClearITPendingBit(USART2, USART_IT_IDLE);//清除串口空闲中断标志位
USART_Cmd(USART2, ENABLE);//使能串口

}

3.再配置DMA初始化

```c
u8 DMA_Rx[Temp_BufSize_LEN] = {0};
u8 DMA_Tx[Temp_BufSize_LEN] = {0};

void DMA1_Config(void)

{

DMA_InitTypeDef DMA_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1,ENABLE);

   /*****DMA发送配置 Memory->Peripheral *****************/
DMA_DeInit(DMA1_Channel4);          //将DMA1_Channel4信道寄存器初始化为默认的重置值。
DMA_InitStructure.DMA_BufferSize = DMA1_MEM_LEN_RX;//设置DMA1的Buffer缓冲区大小，DMA1_MEM_LEN_RX为自定义的变量
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;    //关闭内存到内存
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;    //正常模式
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;  //内存到外设
DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh; //优先级非常高
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; //内存地址递增
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&USART2->TDR; //设置外设接收地址
DMA_InitStructure.DMA_PeripheralInc =  DMA_PeripheralInc_Disable; //外设地址不变
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;    //设置内存数据长度以Byte为单位
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)DMA_Tx;          //设置内存发送地址，DMA_Tx为自定义变量
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte; //设置外设数据长度以Byte为单位
DMA_Init(DMA1_Channel4,&DMA_InitStructure);

DMA_ClearITPendingBit(DMA1_IT_TC4);  //清除DMA_ch4传输完成中断标志
DMA_ITConfig(DMA1_Channel4,DMA_IT_TC,ENABLE); //使能DMA1_CH4传输完成中断
USART_DMACmd(USART2,USART_DMAReq_Tx,ENABLE); //使能串口与DMA发送关联

/*****DMA接收配置 Peripheral->Memory*****************/
DMA_DeInit(DMA1_Channel5);
DMA_InitStructure.DMA_BufferSize = DMA1_MEM_LEN_RX;
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&USART2->RDR;
DMA_InitStructure.DMA_PeripheralInc =  DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)DMA_Rx;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
DMA_Init(DMA1_Channel5,&DMA_InitStructure);

DMA_ClearITPendingBit(DMA1_IT_TC5);
DMA_ITConfig(DMA1_Channel5,DMA_IT_TC,ENABLE);
USART_DMACmd(USART2,USART_DMAReq_Rx,ENABLE);
DMA_Cmd(DMA1_Channel5,ENABLE);  //使能DMA通道5

NVIC_InitStructure.NVIC_IRQChannel = DMA1_Channel4_5_IRQn;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_InitStructure.NVIC_IRQChannelPriority = 1;

NVIC_Init(&NVIC_InitStructure);

}
//注意：DMA初始化没有使能DMA_CH4,我们只需在要发送数据时使能即可

4.用DMA接收数据

void USART2_IRQHandler(void)
{
u32 id = 0;
u8 FIFO_Level = 0,i = 0;
uint16_t Temp_Len=0;
//OverRun Error处理
if(USART_GetFlagStatus(USART2, USART_FLAG_ORE) != RESET)
{
   USART_ReceiveData(USART2);
   USART_ClearFlag(USART2, USART_FLAG_ORE);
}
//接收空闲中断处理
if(USART_GetITStatus(USART2, USART_IT_IDLE) != RESET)
{
   USART_ClearITPendingBit(USART2, USART_IT_IDLE); //清除中断标志位
   DMA_Cmd(DMA1_Channel5, DISABLE);
   Temp_Len= DMA1_MEM_LEN_RX - DMA_GetCurrDataCounter(DMA1_Channel5);//获得传输的数据个数
   DMA_SetCurrDataCounter(DMA1_Channel5, DMA1_MEM_LEN_RX);
   DMA_Cmd(DMA1_Channel5, ENABLE);

   //此部分为自定义的传输协议
   id = ((u32)DMA_Rx[0] << 24) | ((u32)DMA_Rx[1] << 16) | ((u32)DMA_Rx[2] << 8) | (u32)DMA_Rx[3];
   if(((id >> 13) & 0xff) != 0xff && ((id >> 13) & 0xff) != MY485_deviceinf[14])
      return;
   FIFO_Level = RS485_SetRxFifoFillLevel(RS485_FIFO.RS485_RCE);
   if(FIFO_Level > 3)
      return;
   RS485_FIFO.FIFO_RxBuff_DLen[FIFO_Level-1] = Temp_Len;
   for(i = 0; i < RS485_FIFO.FIFO_RxBuff_DLen[FIFO_Level-1]; i++)
      RS485_FIFO.RS485_FIFO_RXBUFF[FIFO_Level-1] = DMA_Rx;

   memset(&DMA_Rx, 0, sizeof(DMA_Rx)); //将DMA中Buffer清空
}

}

5.用DMA发送数据

void DMA_Enable_TX(DMA_Channel_TypeDef *DMA_CHx, u8 len)
{
RS485_TX_Enable(); //由于用的是rs485，故需先置高bussy信号
   DMA_Cmd(DMA_CHx, ENABLE);  //使能通道
//DMA_Cmd(DMA_CHx, DISABLE);
//DMA_SetCurrDataCounter(DMA_CHx, len);
//DMA_Cmd(DMA_CHx, ENABLE);
}

int main(void)
{
int i = 0;

delay_init()
USART2_Init();
RS485_Busy_init();
DMA1_Config();

while(1)
{
DMA_Enable_TX(DMA1_Channel4,DMA1_MEM_LEN_RX);
DMA_Tx[0]='H'; //例如发送H字母

}
}

以上是我对串口DMA的使用理解，希望能帮助到大家，谢谢观看。

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