前记：
stm32使用多个串口通信，这个项目遇到了不少问题，值得反思和深入总结一下。
提纲：
这次的问题，主要有几个部分组成：
A 多串口的DMA配置，这个需要注意，尽量不要使用同一个DMA通道，这个高速的接收数据的时候会出问题。
B 串口的tx和rx配置一定要检查好，不要被复用了。这个是经常遇到的坑。
C 串口的接收完成中断里面尽量少做事情。
源码解析：
这里面注意几个细节：
一个是串口中断的设置，如源码所示：
/**
* @brief This function handles DMA1 channel6 global interrupt.
*/
void DMA1_Channel6_IRQHandler(void)
{
/* USER CODE BEGIN DMA1_Channel6_IRQn 0 */
/* USER CODE END DMA1_Channel6_IRQn 0 */
HAL_DMA_IRQHandler(&hdma_usart2_rx);
/* USER CODE BEGIN DMA1_Channel6_IRQn 1 */
/* USER CODE END DMA1_Channel6_IRQn 1 */
}
/**
* @brief This function handles DMA1 channel6 global interrupt.
*/
void DMA1_Channel3_IRQHandler(void)
{
/* USER CODE BEGIN DMA1_Channel6_IRQn 0 */
/* USER CODE END DMA1_Channel6_IRQn 0 */
HAL_DMA_IRQHandler(&hdma_usart3_rx);
/* USER CODE BEGIN DMA1_Channel6_IRQn 1 */
/* USER CODE END DMA1_Channel6_IRQn 1 */
}
另外一个是串口的配置，如下所示：
void HAL_UART_MspInit(UART_HandleTypeDef* uartHandle)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};
if(uartHandle->Instance==USART2)
{
/* USER CODE BEGIN USART2_MspInit 0 */
/* USER CODE END USART2_MspInit 0 */
/** Initializes the peripherals clock
*/
PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USART2;
PeriphClkInit.Usart2ClockSelection = RCC_USART2CLKSOURCE_PCLK1;
if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
{
Error_Handler();
}
/* USART2 clock enable */
__HAL_RCC_USART2_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
/**USART2 GPIO Configuration
PA2 ------> USART2_TX
PA3 ------> USART2_RX
*/
GPIO_InitStruct.Pin = GPIO_PIN_2|GPIO_PIN_3;
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_USART2;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
/* USART2 DMA Init */
/* USART2_RX Init */
hdma_usart2_rx.Instance = DMA1_Channel6;
hdma_usart2_rx.Init.Request = DMA_REQUEST_2;
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_NORMAL;
hdma_usart2_rx.Init.Priority = DMA_PRIORITY_LOW;
if (HAL_DMA_Init(&hdma_usart2_rx) != HAL_OK)
{
Error_Handler();
}
__HAL_LINKDMA(uartHandle,hdmarx,hdma_usart2_rx);
/* USART2 interrupt Init */
HAL_NVIC_SetPriority(USART2_IRQn, 8, 0);
HAL_NVIC_EnableIRQ(USART2_IRQn);
/* USER CODE BEGIN USART2_MspInit 1 */
__HAL_UART_CLEAR_IDLEFLAG(&huart2);
HAL_UART_Receive_DMA(&huart2, SENSOR_RX_BUFF, GPS_RX_BUFF_SIZE);
__HAL_UART_ENABLE_IT(&huart2,UART_IT_IDLE);
/* USER CODE END USART2_MspInit 1 */
}
else if(uartHandle->Instance==USART3)
{
/* USER CODE BEGIN USART2_MspInit 0 */
/* USER CODE END USART2_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();
}
/* USART2 clock enable */
__HAL_RCC_USART3_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();
/**USART2 GPIO Configuration
PB10 ------> USART3_TX
PB11 ------> USART3_RX
*/
GPIO_InitStruct.Pin = GPIO_PIN_10|GPIO_PIN_11;
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(GPIOB, &GPIO_InitStruct);
/* USART2 DMA Init */
/* USART2_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);
/* USART2 interrupt Init */
HAL_NVIC_SetPriority(USART3_IRQn, 8, 0);
HAL_NVIC_EnableIRQ(USART3_IRQn);
// /* USER CODE BEGIN USART2_MspInit 1 */
__HAL_UART_CLEAR_IDLEFLAG(&huart3);
HAL_UART_Receive_DMA(&huart3, GPS_RX_BUFF, GPS_RX_BUFF_SIZE);
__HAL_UART_ENABLE_IT(&huart3,UART_IT_IDLE);
/* USER CODE END USART2_MspInit 1 */
}
else if(uartHandle->Instance==USART1)
{
/* USER CODE BEGIN USART2_MspInit 0 */
/* USER CODE END USART2_MspInit 0 */
/** Initializes the peripherals clock
*/
PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USART1;
PeriphClkInit.Usart1ClockSelection = RCC_USART1CLKSOURCE_PCLK2;
if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
{
Error_Handler();
}
/* USART1 clock enable */
__HAL_RCC_USART1_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
/**USART2 GPIO Configuration
PA9 ------> USART1_TX
PA10 ------> USART1_RX
*/
GPIO_InitStruct.Pin = GPIO_PIN_10|GPIO_PIN_9;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_PULLUP;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
GPIO_InitStruct.Alternate = GPIO_AF7_USART3;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
// /* USART2 DMA Init */
// /* USART2_RX Init */
// hdma_usart1_rx.Instance = DMA1_Channel6;
// hdma_usart1_rx.Init.Request = DMA_REQUEST_2;
// 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_NORMAL;
// 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);
/* USART2 interrupt Init */
HAL_NVIC_SetPriority(USART1_IRQn, 8, 0);
HAL_NVIC_EnableIRQ(USART1_IRQn);
/* USER CODE BEGIN USART2_MspInit 1 */
/* USER CODE END USART2_MspInit 1 */
}
}
总结：
这个是三个串口正常工作的版本，有一个串口不需要接受数据，就把接收毙掉了。目前三个串口有好的同时工作。