HAL库DAM串口收发

以下是使用HAL库实现DMA串口收发的示例代码：

#include "stm32f4xx_hal.h"

UART_HandleTypeDef huart2;
DMA_HandleTypeDef hdma_usart2_rx;
DMA_HandleTypeDef hdma_usart2_tx;

uint8_t rx_buffer[10];
uint8_t tx_buffer[10] = "Hello DMA!";

void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_DMA_Init(void);
static void MX_USART2_UART_Init(void);

int main(void)
{
  HAL_Init();
  SystemClock_Config();
  MX_GPIO_Init();
  MX_DMA_Init();
  MX_USART2_UART_Init();

  HAL_UART_Receive_DMA(&huart2, rx_buffer, 10);
  HAL_UART_Transmit_DMA(&huart2, tx_buffer, 10);

  while (1)
  {
  }
}

void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
  RCC_OscInitStruct.PLL.PLLM = 16;
  RCC_OscInitStruct.PLL.PLLN = 336;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
  RCC_OscInitStruct.PLL.PLLQ = 7;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  if (HAL_PWREx_EnableOverDrive() != HAL_OK)
  {
    Error_Handler();
  }

  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;
  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5) != HAL_OK)
  {
    Error_Handler();
  }
}

static void MX_USART2_UART_Init(void)
{
  huart2.Instance = USART2;
  huart2.Init.BaudRate = 115200;
  huart2.Init.WordLength = UART_WORDLENGTH_8B;
  huart2.Init.StopBits = UART_STOPBITS_1;
  huart2.Init.Parity = UART_PARITY_NONE;
  huart2.Init.Mode = UART_MODE_TX_RX;
  huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart2.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart2) != HAL_OK)
  {
    Error_Handler();
  }
}

static void MX_DMA_Init(void)
{
  __HAL_RCC_DMA1_CLK_ENABLE();

  HAL_NVIC_SetPriority(DMA1_Stream5_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(DMA1_Stream5_IRQn);

  HAL_NVIC_SetPriority(DMA1_Stream6_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(DMA1_Stream6_IRQn);

  hdma_usart2_rx.Instance = DMA1_Stream5;
  hdma_usart2_rx.Init.Channel = DMA_CHANNEL_4;
  hdma_usart2_rx.Init.Direction = DMA_PERIPH_TO_MEMORY;
  hdma_usart2_rx.Init.PeriphInc = DMA_PINC_DISABLE;
  hdma_usart2_rx.Init.MemInc = DMA_MINC_ENABLE;
  hdma_usart2_rx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
  hdma_usart2_rx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
  hdma_usart2_rx.Init.Mode = DMA_CIRCULAR;
  hdma_usart2_rx.Init.Priority = DMA_PRIORITY_HIGH;
  hdma_usart2_rx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
  if (HAL_DMA_Init(&hdma_usart2_rx) != HAL_OK)
  {
    Error_Handler();
  }

  __HAL_LINKDMA(&huart2, hdmarx, hdma_usart2_rx);

  hdma_usart2_tx.Instance = DMA1_Stream6;
  hdma_usart2_tx.Init.Channel = DMA_CHANNEL_4;
  hdma_usart2_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
  hdma_usart2_tx.Init.PeriphInc = DMA_PINC_DISABLE;
  hdma_usart2_tx.Init.MemInc = DMA_MINC_ENABLE;
  hdma_usart2_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
  hdma_usart2_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
  hdma_usart2_tx.Init.Mode = DMA_NORMAL;
  hdma_usart2_tx.Init.Priority = DMA_PRIORITY_HIGH;
  hdma_usart2_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
  if (HAL_DMA_Init(&hdma_usart2_tx) != HAL_OK)
  {
    Error_Handler();
  }

  __HAL_LINKDMA(&huart2, hdmatx, hdma_usart2_tx);
}

void DMA1_Stream5_IRQHandler(void)
{
  HAL_DMA_IRQHandler(&hdma_usart2_rx);
}

void DMA1_Stream6_IRQHandler(void)
{
  HAL_DMA_IRQHandler(&hdma_usart2_tx);
}

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
  if (huart->Instance == USART2)
  {
    HAL_UART_Transmit_DMA(&huart2, rx_buffer, 10);
  }
}

void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart)
{
  if (huart->Instance == USART2)
  {
    HAL_UART_Receive_DMA(&huart2, rx_buffer, 10);
  }
}

void Error_Handler(void)
{
}

以上代码实现了使用DMA进行串口收发，其中使用了HAL库的函数。需要注意的是，这里使用了循环DMA模式，即在接收完成后自动重新启动DMA传输，以实现连续的数据接收和发送。