STM32串口DMA接收双缓冲
STM32高端MCU（F4、F7等）才支持DMA双缓冲，低端MCU（F1）不支持DMA双缓冲，不过有替代方案可实现类型效果。
一、MCU支持ＤＭＡ双缓冲的情形
不再赘述，参见博客 STM32 串口DMA发送+DMA接收+硬件双缓冲区切换功能实现
二、MCU不支持ＤＭＡ双缓冲，但可通过DMA传输半完成中断替代，以下代码已在F103上验证通过。
1.先通过STM32CubeMX生成串口初始化代码
串口接收DMA一定要选择Circular模式，并且使能串口接收中断
2.使能空闲中断，空闲中断中取出接收数据
3.在DAM接收半完成、完成中断中取出接收数据
usart.c：
/* Includes ------------------------------------------------------------------*/
#include "usart.h"
/* USER CODE BEGIN 0 */
#define DE_UART_DMA_BUF_LEN 128
extern void at_uart_recv_data(uint8_t *pdata, uint16_t len);
static volatile uint8_t RecvDMABuf[DE_UART_DMA_BUF_LEN];
static volatile uint8_t RecvLastIdx = 0;
/* USER CODE END 0 */
UART_HandleTypeDef huart1;
DMA_HandleTypeDef hdma_usart1_tx;
DMA_HandleTypeDef hdma_usart1_rx;
/* USART1 init function */
void MX_USART1_UART_Init(void)
{
huart1.Instance = USART1;
huart1.Init.BaudRate = 115200;
huart1.Init.WordLength = UART_WORDLENGTH_8B;
huart1.Init.StopBits = UART_STOPBITS_1;
huart1.Init.Parity = UART_PARITY_NONE;
huart1.Init.Mode = UART_MODE_TX_RX;
huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
huart1.Init.OverSampling = UART_OVERSAMPLING_16;
if (HAL_UART_Init(&huart1) != HAL_OK)
{
Error_Handler();
}
}
void HAL_UART_MspInit(UART_HandleTypeDef* uartHandle)
{
GPIO_InitTypeDef GPIO_InitStruct = {
0};
if(uartHandle->Instance==USART1)
{
/* USER CODE BEGIN USART1_MspInit 0 */
/* USER CODE END USART1_MspInit 0 */
/* USART1 clock enable */
__HAL_RCC_USART1_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
/**USART1 GPIO Configuration
PA9 ------> USART1_TX
PA10 ------> USART1_RX
*/
GPIO_InitStruct.Pin = GPIO_PIN_9;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
GPIO_InitStruct.Pin = GPIO_PIN_10;
GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
/* USART1 DMA Init */
/* USART1_TX Init */
hdma_usart1_tx.Instance = DMA1_Channel4;
hdma_usart1_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_usart1_tx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_usart1_tx.Init.MemInc = DMA_MINC_ENABLE;
hdma_usart1_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
hdma_usart1_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_usart1_tx.Init.Mode = DMA_NORMAL;
hdma_usart1_tx.Init.Priority = DMA_PRIORITY_LOW;
if (HAL_DMA_Init(&hdma_usart1_tx) != HAL_OK)
{
Error_Handler();
}
__HAL_LINKDMA(uartHandle,hdmatx,hdma_usart1_tx);
/* USART1_RX Init */
hdma_usart1_rx.Instance = DMA1_Channel5;
hdma_usart1_rx.Init.Direction = DMA_PERIPH_TO_MEMORY;
hdma_usart1_rx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_usart1_rx.Init.MemInc = DMA_MINC_ENABLE;
hdma_usart1_rx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
hdma_usart1_rx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_usart1_rx.Init.Mode = DMA_CIRCULAR;
hdma_usart1_rx.Init.Priority = DMA_PRIORITY_LOW;
if (HAL_DMA_Init(&hdma_usart1_rx) != HAL_OK)
{
Error_Handler();
}
__HAL_LINKDMA(uartHandle,hdmarx,hdma_usart1_rx);
/* USART1 interrupt Init */
HAL_NVIC_SetPriority(USART1_IRQn, 5, 0);
HAL_NVIC_EnableIRQ(USART1_IRQn);
/* USER CODE BEGIN USART1_MspInit 1 */
/*Enable the IDLE Interrupt*/
__HAL_UART_ENABLE_IT(uartHandle,UART_IT_IDLE);
__HAL_UART_CLEAR_FLAG(uartHandle, UART_IT_IDLE);
/* USER CODE END USART1_MspInit 1 */
}
}
void HAL_UART_MspDeInit(UART_HandleTypeDef* uartHandle)
{
if(uartHandle->Instance==USART1)
{
/* USER CODE BEGIN USART1_MspDeInit 0 */
/* USER CODE END USART1_MspDeInit 0 */
/* Peripheral clock disable */
__HAL_RCC_USART1_CLK_DISABLE();
/**USART1 GPIO Configuration
PA9 ------> USART1_TX
PA10 ------> USART1_RX
*/
HAL_GPIO_DeInit(GPIOA, GPIO_PIN_9|GPIO_PIN_10);
/* USART1 DMA DeInit */
HAL_DMA_DeInit(uartHandle->hdmatx);
HAL_DMA_DeInit(uartHandle->hdmarx);
/* USART1 interrupt Deinit */
HAL_NVIC_DisableIRQ(USART1_IRQn);
/* USER CODE BEGIN USART1_MspDeInit 1 */
/* USER CODE END USART1_MspDeInit 1 */
}
}
/* USER CODE BEGIN 1 */
/**
* @brief Rx Half Transfer completed callbacks.
* @param huart Pointer to a UART_HandleTypeDef structure that contains
* the configuration information for the specified UART module.
* @retval None
*/
void HAL_UART_RxHalfCpltCallback(UART_HandleTypeDef *huart)
{
if(huart->Instance == huart1.Instance)
{
//DebugPrintf("HAL_UART_RxHalfCpltCallback\n");
uint32_t TotalLen = DE_UART_DMA_BUF_LEN - __HAL_DMA_GET_COUNTER(huart->hdmarx);
if(TotalLen > RecvLastIdx)
{
uint32_t RecvLen = TotalLen - RecvLastIdx;
at_uart_recv_data((uint8_t *)&RecvDMABuf[RecvLastIdx],RecvLen);
RecvLastIdx = TotalLen;
}
}
}
/**
* @brief Rx Transfer completed callbacks.
* @param huart Pointer to a UART_HandleTypeDef structure that contains
* the configuration information for the specified UART module.
* @retval None
*/
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
if(huart->Instance == huart1.Instance)
{
//DebugPrintf("HAL_UART_RxCpltCallback\n");
uint32_t TotalLen = DE_UART_DMA_BUF_LEN;
if(TotalLen > RecvLastIdx)
{
uint32_t RecvLen = TotalLen - RecvLastIdx;
at_uart_recv_data((uint8_t *)&RecvDMABuf[RecvLastIdx],RecvLen);
RecvLastIdx = 0;
}
}
}
/**
* @brief Rx IDLE callback
* @param huart: UART handle.
* @note This example shows a simple way to report end of DMA Tx transfer, and
* you can add your own implementation.
* @retval None
*/
static void UART_IDLE_CallBack(UART_HandleTypeDef *huart)
{
if(huart->Instance == huart1.Instance)
{
//DebugPrintf("UART_IDLE_CallBack\n");
uint32_t TotalLen = DE_UART_DMA_BUF_LEN - __HAL_DMA_GET_COUNTER(huart->hdmarx);
//DebugPrintf("TotalLen:%d\n",TotalLen);
if(TotalLen > RecvLastIdx)
{
uint32_t RecvLen = TotalLen - RecvLastIdx;
at_uart_recv_data((uint8_t *)&RecvDMABuf[RecvLastIdx],RecvLen);
RecvLastIdx = TotalLen;
}
}
}
/**
* @brief UART_Idle_IRQHandler
* @param huart Pointer to a UART_HandleTypeDef structure that contains
* the configuration information for the specified UART module.
* @retval HAL status
*/
void UART_Idle_IRQHandler(UART_HandleTypeDef *huart)
{
if(__HAL_UART_GET_FLAG(huart, UART_FLAG_IDLE) != RESET)
{
__HAL_UART_CLEAR_IDLEFLAG(huart);
__HAL_UART_FLUSH_DRREGISTER(huart);
UART_IDLE_CallBack(huart);
}
}
void UART1_StartReceiveDMA(void)
{
HAL_UART_Receive_DMA(&huart1,(uint8_t *)RecvDMABuf,sizeof(RecvDMABuf));
}
stm32f1xx_it.c
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "stm32f1xx_it.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN TD */
/* USER CODE END TD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
extern void UART_Idle_IRQHandler(UART_HandleTypeDef *huart);
/* USER CODE END 0 */
/* External variables --------------------------------------------------------*/
extern DMA_HandleTypeDef hdma_usart1_tx;
extern DMA_HandleTypeDef hdma_usart1_rx;
extern UART_HandleTypeDef huart1;
extern TIM_HandleTypeDef htim2;
/* USER CODE BEGIN EV */
/* USER CODE END EV */
/******************************************************************************/
/* Cortex-M3 Processor Interruption and Exception Handlers */
/******************************************************************************/
/**
* @brief This function handles Non maskable interrupt.
*/
void NMI_Handler(void)
{
/* USER CODE BEGIN NonMaskableInt_IRQn 0 */
/* USER CODE END NonMaskableInt_IRQn 0 */
/* USER CODE BEGIN NonMaskableInt_IRQn 1 */
/* USER CODE END NonMaskableInt_IRQn 1 */
}
/**
* @brief This function handles Hard fault interrupt.
*/
void HardFault_Handler(void)
{
/* USER CODE BEGIN HardFault_IRQn 0 */
/* USER CODE END HardFault_IRQn 0 */
while (1)
{
/* USER CODE BEGIN W1_HardFault_IRQn 0 */
/* USER CODE END W1_HardFault_IRQn 0 */
}
}
/**
* @brief This function handles Memory management fault.
*/
void MemManage_Handler(void)
{
/* USER CODE BEGIN MemoryManagement_IRQn 0 */
/* USER CODE END MemoryManagement_IRQn 0 */
while (1)
{
/* USER CODE BEGIN W1_MemoryManagement_IRQn 0 */
/* USER CODE END W1_MemoryManagement_IRQn 0 */
}
}
/**
* @brief This function handles Prefetch fault, memory access fault.
*/
void BusFault_Handler(void)
{
/* USER CODE BEGIN BusFault_IRQn 0 */
/* USER CODE END BusFault_IRQn 0 */
while (1)
{
/* USER CODE BEGIN W1_BusFault_IRQn 0 */
/* USER CODE END W1_BusFault_IRQn 0 */
}
}
/**
* @brief This function handles Undefined instruction or illegal state.
*/
void UsageFault_Handler(void)
{
/* USER CODE BEGIN UsageFault_IRQn 0 */
/* USER CODE END UsageFault_IRQn 0 */
while (1)
{
/* USER CODE BEGIN W1_UsageFault_IRQn 0 */
/* USER CODE END W1_UsageFault_IRQn 0 */
}
}
/**
* @brief This function handles Debug monitor.
*/
void DebugMon_Handler(void)
{
/* USER CODE BEGIN DebugMonitor_IRQn 0 */
/* USER CODE END DebugMonitor_IRQn 0 */
/* USER CODE BEGIN DebugMonitor_IRQn 1 */
/* USER CODE END DebugMonitor_IRQn 1 */
}
/******************************************************************************/
/* STM32F1xx Peripheral Interrupt Handlers */
/* Add here the Interrupt Handlers for the used peripherals. */
/* For the available peripheral interrupt handler names, */
/* please refer to the startup file (startup_stm32f1xx.s). */
/******************************************************************************/
/**
* @brief This function handles DMA1 channel4 global interrupt.
*/
void DMA1_Channel4_IRQHandler(void)
{
/* USER CODE BEGIN DMA1_Channel4_IRQn 0 */
/* USER CODE END DMA1_Channel4_IRQn 0 */
HAL_DMA_IRQHandler(&hdma_usart1_tx);
/* USER CODE BEGIN DMA1_Channel4_IRQn 1 */
/* USER CODE END DMA1_Channel4_IRQn 1 */
}
/**
* @brief This function handles DMA1 channel5 global interrupt.
*/
void DMA1_Channel5_IRQHandler(void)
{
/* USER CODE BEGIN DMA1_Channel5_IRQn 0 */
/* USER CODE END DMA1_Channel5_IRQn 0 */
HAL_DMA_IRQHandler(&hdma_usart1_rx);
/* USER CODE BEGIN DMA1_Channel5_IRQn 1 */
/* USER CODE END DMA1_Channel5_IRQn 1 */
}
/**
* @brief This function handles TIM2 global interrupt.
*/
void TIM2_IRQHandler(void)
{
/* USER CODE BEGIN TIM2_IRQn 0 */
/* USER CODE END TIM2_IRQn 0 */
HAL_TIM_IRQHandler(&htim2);
/* USER CODE BEGIN TIM2_IRQn 1 */
/* USER CODE END TIM2_IRQn 1 */
}
/**
* @brief This function handles USART1 global interrupt.
*/
void USART1_IRQHandler(void)
{
/* USER CODE BEGIN USART1_IRQn 0 */
/* USER CODE END USART1_IRQn 0 */
HAL_UART_IRQHandler(&huart1);
/* USER CODE BEGIN USART1_IRQn 1 */
UART_Idle_IRQHandler(&huart1);
/* USER CODE END USART1_IRQn 1 */
}
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
1、此时DMA缓冲区类似一个FIFI，RecvLastIdx用来指示当前可以读取数据的起始位置。
2、在ＤＭＡ接收半完成中断和ＤＭＡ接收完成中断之后的空闲中断中不能重复取接收数据，通过判断TotalLen > RecvLastIdx可避免。
3、该方法也适用于F4、F7等高端MCU。