STM32的HAL库写HalfDuplex通信程序

以下是一个使用STM32 HAL库编写的HalfDuplex通信程序示例：

#include "stm32f4xx_hal.h"

#define UART_TX_PIN GPIO_PIN_9
#define UART_RX_PIN GPIO_PIN_10

UART_HandleTypeDef huart;

void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART1_UART_Init(void);

int main(void)
{
  HAL_Init();

  SystemClock_Config();

  MX_GPIO_Init();
  MX_USART1_UART_Init();

  uint8_t txBuffer[] = "Hello, World!\r\n";
  uint8_t rxBuffer[20];

  while (1)
  {
    HAL_UART_Transmit(&huart, txBuffer, sizeof(txBuffer), HAL_MAX_DELAY);
    HAL_UART_Receive(&huart, rxBuffer, sizeof(rxBuffer), HAL_MAX_DELAY);
  }
}

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

  /** Configure the main internal regulator output voltage
  */
  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }
  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
  {
    Error_Handler();
  }
}

static void MX_USART1_UART_Init(void)
{
  huart.Instance = USART1;
  huart.Init.BaudRate = 115200;
  huart.Init.WordLength = UART_WORDLENGTH_8B;
  huart.Init.StopBits = UART_STOPBITS_1;
  huart.Init.Parity = UART_PARITY_NONE;
  huart.Init.Mode = UART_MODE_TX_RX;
  huart.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart) != HAL_OK)
  {
    Error_Handler();
  }
}

static void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  __HAL_RCC_GPIOA_CLK_ENABLE();

  GPIO_InitStruct.Pin = UART_TX_PIN;
  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_USART1;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  GPIO_InitStruct.Pin = UART_RX_PIN;
  GPIO_InitStruct.Mode = GPIO_MODE_AF_OD;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
  GPIO_InitStruct.Alternate = GPIO_AF7_USART1;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
}

在这个示例中，我们使用USART1作为通信接口，并初始化了GPIO和UART。在主循环中，我们使用HAL_UART_Transmit和HAL_UART_Receive函数进行数据的发送和接收。这里使用了HAL_MAX_DELAY参数，表示函数会一直阻塞直到数据传输完成。在实际应用中，可以根据需要设置合适的超时时间。