当多个串口数据都有大量数据来时,我们如何最佳处理STM32串口通信数据?
可以通过FreeRTOS+队列的发送方式。
下面将串口DMA发送处理过程
中心思想:
1、建立一个大的环形数组
2、发送的数据时,将数据存入到大的数组
3、需要发送数据的长度以及在大数组中的位置,通过队列,发送出去。
4、通过队列,等待有数据进入队列。
5、启动DMA,等待DMA传输完成。
/******************************************************************
将需要发送的数据存入一个大数组内,通过队列发送,将长度,以及数组内的地址
发送出去。 数组的大小可以是队列项目数的N倍,一般5倍就好了,队列项目数5个
已经不少了。
即:假如创建5个队列消息,每个长度为4字节。数组大小 MAX_FRAME_COMM_BUFFER_SIZE
=5*每一次串口传输数据长度;
static uint8_t txbuf_Blue_DMA[MAX_FRAME_COMM_BUFFER_SIZE]; /*缓存的数组大小*/
DMA_MemoryBaseAddr=txbuf_Blue_tmp;
*****************************************************************/
void USART1_SendData(uint8_t *ps,uint16_t len)
{
uint16_t i;
BufferLoopData_Typedef buffer_loop;
buffer_loop.start_addr = ps_tbwr_Blue;
buffer_loop.len = len;
for (i=0;i<len;i++)
{
if (ps_tbwr_Blue >= MAX_FRAME_COMM_BUFFER_SIZE)
{
ps_tbwr_Blue = 0;
}
txbuf_Blue_DMA[ps_tbwr_Blue] = *(ps+i);//txbuf_Blue_DMA为
ps_tbwr_Blue++;
}
xQueueSendToBack(xQueue_Blue_tx,(void *)&buffer_loop,portMAX_DELAY);
}
/******************************************************************
队列接收到数据所在数组的地址以及长度,然后通过DMA发送出去
*****************************************************************/
void USART1_SendTask(void const * argument)
{
uint16_t i;
BufferLoopData_Typedef buffer_loop;
extern uint8_t txbuf_Blue_tmp[MAX_FRAME_COMM_LEN];
for (;;)
{
xQueueReceive(xQueue_Blue_tx,&buffer_loop,portMAX_DELAY);
//SCB_CleanDCache();
for (i=0;i<buffer_loop.len;i++)
{
if (buffer_loop.start_addr >= MAX_FRAME_COMM_BUFFER_SIZE)
{
buffer_loop.start_addr = buffer_loop.start_addr - MAX_FRAME_COMM_BUFFER_SIZE;
}
txbuf_Blue_tmp[i] = txbuf_Blue_DMA[buffer_loop.start_addr];
buffer_loop.start_addr += 1;
}
//SCB_CleanInvalidateDCache();
Uart1_DMASend_Start(&txbuf_Blue_tmp[0],buffer_loop.len);//通过DMA发送
xSemaphoreTake(BinarySem_UART1_tx_finish_Handle,portMAX_DELAY); //等待DMA发送成功
taskYIELD();
}
}
串口DMA发送代码:
/**********************************************************************
串口USART1 DMA发送数据
********************************/
uint8_t Uart1_DMASend_Start(uint8_t* buffer, u16 size)
{
if(!size) return 0;
while (DMA_GetCurrDataCounter(DMA1_Channel4));
if(buffer) memcpy(txbuf_Blue_tmp, buffer,(size > 1024?1024:size));
//DMA发送数据,DMA
DMA_Cmd(DMA1_Channel4, DISABLE);
DMA1_Channel4->CNDTR = size;
DMA_Cmd(DMA1_Channel4, ENABLE);
return size;
}
中断代码:
//中断传输完成
void DMA1_Channel4_IRQHandler(void)
{
portBASE_TYPE xHigherPriorityTaskWoken;
if(DMA_GetITStatus(DMA1_FLAG_TC4))
{
DMA_ClearFlag(DMA1_FLAG_TC4);
xSemaphoreGiveFromISR(BinarySem_UART1_tx_finish_Handle,&xHigherPriorityTaskWoken);
}
}
串口初始化:
USART_Config();
UART_DMA_Config();
串口初始化详细代码
//串口DMA初始化
void UART_DMA_Config(void){
NVIC_InitTypeDef NVIC_InitStructure;
DMA_Config(DMA1_Channel4,(u32)&USART1->DR,(u32)txbuf_Blue_tmp,DMA_DIR_PeripheralDST,DMA_Priority_Medium,0,DMA_Mode_Normal);
//txbuf_Blue_tmp USART1 DMA发送基地址
DMA_Config(DMA1_Channel5,(u32)&USART1->DR,(u32)rxbuf_Uart1_DMA,DMA_DIR_PeripheralSRC,DMA_Priority_Medium,MaxSize_FRAME_DISP,DMA_Mode_Circular);
//rxbuf_Uart1_DMADMA接收基地址
//NVIC初始化
NVIC_InitStructure.NVIC_IRQChannel = DMA1_Channel4_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=6 ;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
DMA_ITConfig(DMA1_Channel4,DMA_IT_TC,ENABLE);
USART_DMACmd(USART1,USART_DMAReq_Tx,ENABLE);
USART_DMACmd(USART1,USART_DMAReq_Rx,ENABLE);
DMA_Cmd (USART_RX_DMA_CHANNEL,ENABLE);
}
//串口配置初始化
void USART_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA|RCC_APB2 Periph_AFIO, ENABLE);
//USART1_TX GPIOA.9
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; //PA.9
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOA, &GPIO_InitStructure);
//USART1_RX GPIOA.10
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;//PA10
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(GPIOA, &GPIO_InitStructure);
NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=6 ;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
USART_InitStructure.USART_BaudRate = DEBUG_USART_BAUDRATE;
USART_InitStructure.USART_WordLength = USART_WordLength_8b;
USART_InitStructure.USART_StopBits = USART_StopBits_1;
USART_InitStructure.USART_Parity = USART_Parity_No;
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
USART_Init(USART1, &USART_InitStructure);
USART_ITConfig(USART1,USART_IT_IDLE,ENABLE);
USART_Cmd(USART1, ENABLE);
}
//DMA初始化 做成了一个封装函数
void DMA_Config(DMA_Channel_TypeDef*DMA_CHx,u32 PeripheralBaseAddr,u32 MemoryBaseAddr,u32 dma_dir,u32 priority,u16 bufsize,u32 mode)
{
DMA_InitTypeDef DMA_InitStructure;
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
DMA_DeInit(DMA_CHx);
DMA_InitStructure.DMA_PeripheralBaseAddr = PeripheralBaseAddr;
DMA_InitStructure.DMA_MemoryBaseAddr = MemoryBaseAddr;
DMA_InitStructure.DMA_DIR = dma_dir;
DMA_InitStructure.DMA_BufferSize = bufsize;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
DMA_InitStructure.DMA_Mode = mode;
DMA_InitStructure.DMA_Priority = priority;
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_Init(DMA_CHx, &DMA_InitStructure);
}
下一篇文章来介绍如何通过DMA+FreeRTOS+IDLE接收数据