以串口3为例，初始化部分为STM32CubeMX生成代码
串口初始化
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UART_HandleTypeDef huart3;
DMA_HandleTypeDef hdma_usart3_rx;
DMA_HandleTypeDef hdma_usart3_tx;
/* USART3 init function */
void MX_USART3_UART_Init(void)
{
/* USER CODE BEGIN USART3_Init 0 */
/* USER CODE END USART3_Init 0 */
/* USER CODE BEGIN USART3_Init 1 */
/* USER CODE END USART3_Init 1 */
huart3.Instance = USART3;
huart3.Init.BaudRate = 115200;
huart3.Init.WordLength = UART_WORDLENGTH_8B;
huart3.Init.StopBits = UART_STOPBITS_1;
huart3.Init.Parity = UART_PARITY_NONE;
huart3.Init.Mode = UART_MODE_TX_RX;
huart3.Init.HwFlowCtl = UART_HWCONTROL_NONE;
huart3.Init.OverSampling = UART_OVERSAMPLING_16;
huart3.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
huart3.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
if (HAL_UART_Init(&huart3) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN USART3_Init 2 */
/* USER CODE END USART3_Init 2 */
}
void HAL_UART_MspInit(UART_HandleTypeDef* uartHandle)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};
if(uartHandle->Instance == USART3)
{
/* USER CODE BEGIN USART3_MspInit 0 */
/* USER CODE END USART3_MspInit 0 */
/** Initializes the peripherals clock
*/
PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USART3;
PeriphClkInit.Usart3ClockSelection = RCC_USART3CLKSOURCE_PCLK1;
if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
{
Error_Handler();
}
/* USART3 clock enable */
__HAL_RCC_USART3_CLK_ENABLE();
__HAL_RCC_GPIOC_CLK_ENABLE();
/**USART3 GPIO Configuration
PC4 ------> USART3_TX
PC5 ------> USART3_RX
*/
GPIO_InitStruct.Pin = GPIO_PIN_4 | GPIO_PIN_5;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
GPIO_InitStruct.Alternate = GPIO_AF7_USART3;
HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
/* USART3 DMA Init */
/* USART3_RX Init */
hdma_usart3_rx.Instance = DMA1_Channel3;
hdma_usart3_rx.Init.Request = DMA_REQUEST_2;
hdma_usart3_rx.Init.Direction = DMA_PERIPH_TO_MEMORY;
hdma_usart3_rx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_usart3_rx.Init.MemInc = DMA_MINC_ENABLE;
hdma_usart3_rx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
hdma_usart3_rx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_usart3_rx.Init.Mode = DMA_NORMAL;
hdma_usart3_rx.Init.Priority = DMA_PRIORITY_LOW;
if (HAL_DMA_Init(&hdma_usart3_rx) != HAL_OK)
{
Error_Handler();
}
__HAL_LINKDMA(uartHandle, hdmarx, hdma_usart3_rx);
/* USART3_TX Init */
hdma_usart3_tx.Instance = DMA1_Channel2;
hdma_usart3_tx.Init.Request = DMA_REQUEST_2;
hdma_usart3_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_usart3_tx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_usart3_tx.Init.MemInc = DMA_MINC_ENABLE;
hdma_usart3_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
hdma_usart3_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_usart3_tx.Init.Mode = DMA_NORMAL;
hdma_usart3_tx.Init.Priority = DMA_PRIORITY_LOW;
if (HAL_DMA_Init(&hdma_usart3_tx) != HAL_OK)
{
Error_Handler();
}
__HAL_LINKDMA(uartHandle,hdmatx,hdma_usart3_tx);
/* USART3 interrupt Init */
HAL_NVIC_SetPriority(USART3_IRQn, 1, 0);
HAL_NVIC_EnableIRQ(USART3_IRQn);
/* USER CODE BEGIN USART3_MspInit 1 */
/* USER CODE END USART3_MspInit 1 */
}
}
void HAL_UART_MspDeInit(UART_HandleTypeDef* uartHandle)
{
if(uartHandle->Instance == USART3)
{
/* USER CODE BEGIN USART3_MspDeInit 0 */
/* USER CODE END USART3_MspDeInit 0 */
/* Peripheral clock disable */
__HAL_RCC_USART3_CLK_DISABLE();
/**USART3 GPIO Configuration
PC4 ------> USART3_TX
PC5 ------> USART3_RX
*/
HAL_GPIO_DeInit(GPIOC, GPIO_PIN_4 | GPIO_PIN_5);
/* USART3 DMA DeInit */
HAL_DMA_DeInit(uartHandle->hdmarx);
HAL_DMA_DeInit(uartHandle->hdmatx);
/* USART3 interrupt Deinit */
HAL_NVIC_DisableIRQ(USART3_IRQn);
/* USER CODE BEGIN USART3_MspDeInit 1 */
/* USER CODE END USART3_MspDeInit 1 */
}
}
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
DMA初始化
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/**
* Enable DMA controller clock
*/
void MX_DMA_Init(void)
{
/* DMA controller clock enable */
__HAL_RCC_DMA1_CLK_ENABLE();
/* DMA interrupt init */
/* DMA1_Channel2_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA1_Channel2_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(DMA1_Channel2_IRQn);
/* DMA1_Channel3_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA1_Channel3_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(DMA1_Channel3_IRQn);
}
中断服务函数
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/**
* @brief This function handles USART3 global interrupt.
*/
void USART3_IRQHandler(void)
{
/* USER CODE BEGIN USART3_IRQn 0 */
/* USER CODE END USART3_IRQn 0 */
HAL_UART_IRQHandler(&huart3);
/* USER CODE BEGIN USART3_IRQn 1 */
/* USER CODE END USART3_IRQn 1 */
}
应用部分，为自己编写代码
开机启用DMA接收
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// 串口接收数据控制结构体
typedef struct
{
uint8_t RxBuffer[USART_RX_MAX_LENGTH];
uint16_t Size;
uint8_t FrameFg;
}WS_RxUsartInfoTypeDef;
WS_RxUsartInfoTypeDef uart3Rx;
void WS_USART_Rx_Tx_Init(void)
{
// 启用DMA接收
HAL_UARTEx_ReceiveToIdle_DMA(&huart3, uart3Rx.RxBuffer, sizeof(uart3Rx.RxBuffer) - 1) ;
}
发送函数
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// 使用串口发送数据时，调用此函数
HAL_StatusTypeDef HAL_UART_Transmit_DMA(UART_HandleTypeDef *huart, const uint8_t *pData, uint16_t Size);
重写发送完成回调函数
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void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart)
{
/* Prevent unused argument(s) compilation warning */
UNUSED(huart);
/* NOTE: This function should not be modified, when the callback is needed,
the HAL_UART_TxCpltCallback could be implemented in the user file
*/
if(huart->Instance == USART3)
{
//此处代表发送完成，若使用RS485通讯，可在此切换接收模式
}
}
重写接收完成回调函数
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void HAL_UARTEx_RxEventCallback(UART_HandleTypeDef *huart, uint16_t Size)
{
// uint16_t len ;
/* Prevent unused argument(s) compilation warning */
UNUSED(huart);
if(huart->Instance == USART3)
{
if(huart->RxEventType == HAL_UART_RXEVENT_IDLE)
{
uart3Rx.FrameFg = 1;
uart3Rx.Size = Size;
// 启用DMA接收
HAL_UARTEx_ReceiveToIdle_DMA(&huart3, uart3Rx.RxBuffer, sizeof(uart3Rx.RxBuffer) - 1) ;
// 可在此处调用接收数据处理函数
}
}
}