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227 lines
7.7 KiB
227 lines
7.7 KiB
2 years ago
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## DMA
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F103ZET usart2 DMA
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***RX引脚配置为上拉 Pull-up***
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### CubeMX配置DMA
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#### dma.h dma.c 初始化
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```C
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void MX_DMA_Init(void)
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{
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/* DMA controller clock enable */
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__HAL_RCC_DMA1_CLK_ENABLE();
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/* DMA interrupt init */
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/* DMA1_Channel6_IRQn interrupt configuration */
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HAL_NVIC_SetPriority(DMA1_Channel6_IRQn, 2, 2);
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HAL_NVIC_EnableIRQ(DMA1_Channel6_IRQn);
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/* DMA1_Channel7_IRQn interrupt configuration */
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HAL_NVIC_SetPriority(DMA1_Channel7_IRQn, 2, 2);
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HAL_NVIC_EnableIRQ(DMA1_Channel7_IRQn);
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}
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```
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#### usart.c
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定义DMA 结构体
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DMA_HandleTypeDef hdma_usart2_rx;
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DMA_HandleTypeDef hdma_usart2_tx;
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对应串口 HAL_UART_MspInit
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```c
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/* USART2 DMA Init */
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/* USART2_RX Init */
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hdma_usart2_rx.Instance = DMA1_Channel6;
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hdma_usart2_rx.Init.Direction = DMA_PERIPH_TO_MEMORY;
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hdma_usart2_rx.Init.PeriphInc = DMA_PINC_DISABLE;
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hdma_usart2_rx.Init.MemInc = DMA_MINC_ENABLE;
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hdma_usart2_rx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
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hdma_usart2_rx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
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hdma_usart2_rx.Init.Mode = DMA_NORMAL;
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hdma_usart2_rx.Init.Priority = DMA_PRIORITY_LOW;
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if (HAL_DMA_Init(&hdma_usart2_rx) != HAL_OK)
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{
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Error_Handler();
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}
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__HAL_LINKDMA(uartHandle,hdmarx,hdma_usart2_rx);
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/* USART2_TX Init */
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hdma_usart2_tx.Instance = DMA1_Channel7;
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hdma_usart2_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
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hdma_usart2_tx.Init.PeriphInc = DMA_PINC_DISABLE;
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hdma_usart2_tx.Init.MemInc = DMA_MINC_ENABLE;
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hdma_usart2_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
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hdma_usart2_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
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hdma_usart2_tx.Init.Mode = DMA_NORMAL;
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hdma_usart2_tx.Init.Priority = DMA_PRIORITY_LOW;
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if (HAL_DMA_Init(&hdma_usart2_tx) != HAL_OK)
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{
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Error_Handler();
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}
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__HAL_LINKDMA(uartHandle,hdmatx,hdma_usart2_tx);
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/* USART2 interrupt Init */
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HAL_NVIC_SetPriority(USART2_IRQn, 0, 0);
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HAL_NVIC_EnableIRQ(USART2_IRQn);
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```
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对应的 HAL_UART_MspDeInit
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HAL_DMA_DeInit(uartHandle->hdmarx);
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HAL_DMA_DeInit(uartHandle->hdmatx);
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### stm32f1xx_it.h .c
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extern DMA_HandleTypeDef 引入DMA定义
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void DMA1_Channel6_IRQHandler(void);
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void DMA1_Channel7_IRQHandler(void);
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void DMA1_Channel6_IRQHandler(void)
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{
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HAL_DMA_IRQHandler(&hdma_usart2_rx);
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}
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void DMA1_Channel7_IRQHandler(void)
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{
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HAL_DMA_IRQHandler(&hdma_usart2_tx);
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}
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### main.h main.c
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#include "dma.h"
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MX_DMA_Init(); 在串口之前初始化，否则不能输出
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### usart dma 发送接收
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HAL_UART_Transmit_DMA();串口DMA模式发送
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HAL_UART_Transmit_DMA();串口DMA模式接收
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HAL_UART_Receive_DMA(&huart2, Rxbuf, sizeof(Rxbuf));
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UART一旦开启DMA之后，DMA收发中断都是强制开启的，所以DMA收发函数也可以编写回调函数。
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```c
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void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
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{
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if(huart->Instance==USART2)
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{
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HAL_UART_Transmit_DMA(&huart2, ACKbuf, sizeof(ACKbuf));
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// HAL_UART_Receive_IT(&huart2, Rxbuf, sizeof(Rxbuf)); // 重新使用串口接收中断
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}
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}
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```
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### DMA 相关函数
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__HAL_DMA_GET_COUNTER 获取DMA剩余未接收数据
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HAL_UART_Transmit 串口阻塞方式发送函数
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HAL_UART_Transmit_IT 串口中断方式发送函数
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HAL_UART_Receive_IT 串口中断方式接收数据
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HAL_UART_Transmit_DMA 串口DMA方式发送函数
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HAL_UART_Receive_DMA 串口DMA方式接收函数
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HAL_UART_TxCpltCallback 串口发送完成回调函数
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HAL_UART_RxCpltCallback 串口接收完成回调函数-- 和中断模式函数一样
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HAL_UART_RxHalfCpltCallback 串口接收过半回调函数
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### DMA 模式
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普通模式：当传输数据量为0时，需要程序中手动将传输数据量重新设置满才能开启下一次的DMA数据传输。
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循环模式：则当传输数据量为0时，会自动将传输数据量设置为满的，这样数据就能不断的传输。双缓冲
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但有时为了安全，当我们设置的DMA缓冲区大小大于一次完整的数据时，当接收完一次数据后，Counter值还没有变为0，这时不会自动指向另一个缓冲区，所以这时候我们就需要手动更改指向下一个缓冲区。（也就是当第一帧数据传输完成后，Counter值不会自动填满，且内存区域还是指向Memory0，然后我们将剩余数据量保存下来，再将Counter值填满，接着把DMA指向Memory1，最后通过判断剩余数据量来决定是否对数据进行处理）
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双缓冲的数据存储格式
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uint8_t sbus_rx_buffer[2][18u];
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DMA_InitStruct.DMA_BufferSize = 18;
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DMA_InitStruct.DMA_Memory0BaseAddr = (uint32_t)&sbus_rx_buffer[0][0];
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DMA_DoubleBufferModeConfig(DMA1_Stream1,(uint32_t)&sbus_rx_buffer[1][0],DMA_Memory_0); //first used memory configuration
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DMA_DoubleBufferModeCmd(DMA1_Stream1, ENABLE);
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空闲中断计算 长度,及中间数据处理方法参考
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```c
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uint32_t temp;
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if(USART1 == huart1.Instance)//判断是否为串口1中断
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{
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if(RESET != __HAL_UART_GET_FLAG(&huart1,UART_FLAG_IDLE))//如果为串口1空闲
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{
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__HAL_UART_CLEAR_IDLEFLAG(&huart1);//清除中断标志
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HAL_UART_DMAStop(&huart1);//停止DMA接收
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temp = __HAL_DMA_GET_COUNTER(&hdma_usart1_rx);//获取DMA当前还有多少未填充
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Rx_len_1 = BUFFERSIZE_1 - temp; //计算串口接收到的数据个数
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HAL_UART_Transmit_DMA(&huart1,ReceiveBuff_1,Rx_len_1);//发送数据
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Rx_len_1=0;//接收数据长度清零
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HAL_UART_Receive_DMA(&huart1,ReceiveBuff_1,BUFFERSIZE_1);//开启下一次接收
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}
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}
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```
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#### DMA 调试
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监控半满，满状态。监控满后，指针是否重回开头接收
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可以串口监控
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huart.Init.BaudRate
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huart->RxXferSize 为Rx需要接收的大小
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__HAL_DMA_GET_COUNTER(huart2.hdmarx) 可以获取剩余的空间
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const uint8_t *pTxBuffPtr; /*!< Pointer to UART Tx transfer Buffer */
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uint16_t TxXferSize; /*!< UART Tx Transfer size */
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__IO uint16_t TxXferCount; /*!< UART Tx Transfer Counter */
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uint8_t *pRxBuffPtr; /*!< Pointer to UART Rx transfer Buffer */
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uint16_t RxXferSize; /*!< UART Rx Transfer size */
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__IO uint16_t RxXferCount; /*!< UART Rx Transfer Counter */
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__HAL_DMA_GET_COUNTER(huart2.hdmarx) 可以获取剩余的空间
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获得 dma-init-CNDTR值
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定义接收数据的结构
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```C
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typedef struct
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{
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uint8_t RxBuffer[RCV_BUF_LENGTH]; /* 接收缓冲区 */
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uint16_t RxEndIndex; /* 尾索引值 */
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FlagStatus RxEndFlag ; /* 接收结束标识 */
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}Usart_BufTypeDef;
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```
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半满中断标志：
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标准库 ：DMA_ITConfig(DMA1_Channel4, DMA_IT_HT, ENABLE);
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HAL库： __HAL_UART_ENABLE_IT(&huart2, DMA_IT_HT);
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可以查DMA中断位置，中断函数要清除半满标记
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开启半满中断后，可以看到半满的LED 翻转
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如何解决 后续出现的错误？？ 获得空余数
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// __HAL_DMA_CLEAR_FLAG(&hdma_usart2_rx, DMA_IT_HT);
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__HAL_DMA_ENABLE_IT(&hdma_usart2_rx, DMA_IT_HT );
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__HAL_UART_CLEAR_FLAG(&huart2, DMA_IT_HT);
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解决串口发送DMA只能发送一次的问题
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注意，在DMA传输过程中，会将串口从READY状态改为发送BUSY状态（软件修改）：huart->gState = HAL_UART_STATE_BUSY_TX;但是在DMA完成本次传输工作以后，并没有将串口从发送BUSY状态改回READY状态
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DMA 中断函数可以如下处理一些错误
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hdma->XferHalfCpltCallback
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if (hdma->XferErrorCallback != NULL)
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{
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/* Transfer error callback */
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hdma->XferErrorCallback(hdma);
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}
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### 思路：
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DMA 采集， 采集立刻复制数据， 轮询处理数据， 判断是否收集完成
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