stm32两个串口通信

在STM32中，可以使用多个串口实现通信。以下是两个串口通信的示例：

1. 使用USART1和USART2进行通信

首先需要在STM32的CubeMX中配置两个串口的引脚和时钟。然后在代码中初始化这两个串口，并使用HAL库提供的函数进行数据传输。

#include "stm32f1xx_hal.h"

UART_HandleTypeDef huart1;
UART_HandleTypeDef huart2;

int main(void)
{
  HAL_Init();
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_USART1_CLK_ENABLE();
  __HAL_RCC_USART2_CLK_ENABLE();

  GPIO_InitTypeDef GPIO_InitStruct = {0};
  GPIO_InitStruct.Pin = GPIO_PIN_9|GPIO_PIN_10;
  GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  huart1.Instance = USART1;
  huart1.Init.BaudRate = 9600;
  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;
  HAL_UART_Init(&huart1);

  huart2.Instance = USART2;
  huart2.Init.BaudRate = 9600;
  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;
  HAL_UART_Init(&huart2);

  while (1)
  {
    uint8_t data[50];
    if (HAL_UART_Receive(&huart1, data, 50, 1000) == HAL_OK)
    {
      HAL_UART_Transmit(&huart2, data, strlen(data), 1000);
    }
    if (HAL_UART_Receive(&huart2, data, 50, 1000) == HAL_OK)
    {
      HAL_UART_Transmit(&huart1, data, strlen(data), 1000);
    }
  }
}

2. 使用USART3和UART4进行通信

同样需要在CubeMX中配置引脚和时钟，并在代码中初始化这两个串口并传输数据。

#include "stm32f1xx_hal.h"

UART_HandleTypeDef huart3;
UART_HandleTypeDef huart4;

int main(void)
{
  HAL_Init();
  __HAL_RCC_GPIOB_CLK_ENABLE();
  __HAL_RCC_USART3_CLK_ENABLE();
  __HAL_RCC_UART4_CLK_ENABLE();

  GPIO_InitTypeDef GPIO_InitStruct = {0};
  GPIO_InitStruct.Pin = GPIO_PIN_10|GPIO_PIN_11;
  GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

  huart3.Instance = USART3;
  huart3.Init.BaudRate = 9600;
  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;
  HAL_UART_Init(&huart3);

  huart4.Instance = UART4;
  huart4.Init.BaudRate = 9600;
  huart4.Init.WordLength = UART_WORDLENGTH_8B;
  huart4.Init.StopBits = UART_STOPBITS_1;
  huart4.Init.Parity = UART_PARITY_NONE;
  huart4.Init.Mode = UART_MODE_TX_RX;
  huart4.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart4.Init.OverSampling = UART_OVERSAMPLING_16;
  HAL_UART_Init(&huart4);

  while (1)
  {
    uint8_t data[50];
    if (HAL_UART_Receive(&huart3, data, 50, 1000) == HAL_OK)
    {
      HAL_UART_Transmit(&huart4, data, strlen(data), 1000);
    }
    if (HAL_UART_Receive(&huart4, data, 50, 1000) == HAL_OK)
    {
      HAL_UART_Transmit(&huart3, data, strlen(data), 1000);
    }
  }
}

以上两个示例都是基于HAL库实现的，也可以使用其他库或裸机代码实现串口通信。