stm32单片机rs485标准库程序

下面是基于HAL库的stm32单片机rs485标准库程序，供您参考：

#include "stm32f1xx_hal.h"

/* RS485 control pin */
#define RS485_CTRL_Pin GPIO_PIN_12
#define RS485_CTRL_GPIO_Port GPIOB

/* UART handler */
UART_HandleTypeDef huart1;

/* Function prototypes */
void MX_GPIO_Init(void);
void MX_USART1_UART_Init(void);

int main(void)
{
  HAL_Init();
  MX_GPIO_Init();
  MX_USART1_UART_Init();

  uint8_t uartData[10] = {0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF, 0x11, 0x22, 0x33, 0x44};

  while (1)
  {
    /* Set RS485 in transmit mode */
    HAL_GPIO_WritePin(RS485_CTRL_GPIO_Port, RS485_CTRL_Pin, GPIO_PIN_SET);

    /* Send data over UART */
    if(HAL_UART_Transmit(&huart1, uartData, sizeof(uartData), HAL_MAX_DELAY) != HAL_OK)
    {
      /* Error handling */
    }

    /* Wait for transmission to complete */
    while(HAL_UART_GetState(&huart1) != HAL_UART_STATE_READY);

    /* Set RS485 in receive mode */
    HAL_GPIO_WritePin(RS485_CTRL_GPIO_Port, RS485_CTRL_Pin, GPIO_PIN_RESET);

    /* Wait for data to be received */
    if(HAL_UART_Receive(&huart1, uartData, sizeof(uartData), HAL_MAX_DELAY) != HAL_OK)
    {
      /* Error handling */
    }

    /* Process received data */
    //...
  }
}

/* Initialize all configured peripherals */
void MX_GPIO_Init(void)
{
  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOB_CLK_ENABLE();

  /* Configure RS485 control pin */
  GPIO_InitTypeDef GPIO_InitStruct = {0};
  GPIO_InitStruct.Pin = RS485_CTRL_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(RS485_CTRL_GPIO_Port, &GPIO_InitStruct);
}

/* USART1 init function */
void MX_USART1_UART_Init(void)
{
  /* USART1 clock enable */
  __HAL_RCC_USART1_CLK_ENABLE();

  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;

  if (HAL_UART_Init(&huart1) != HAL_OK)
  {
    /* Error handling */
  }
}

在这个例子中，我们使用了USART1作为RS485通讯口，并且使用了PB12引脚作为RS485控制引脚。在发送数据之前，我们将控制引脚设置为发送模式，发送完毕后将其设置为接收模式。接收数据时，我们只需等待数据到达即可。

请注意，此代码仅供参考，您需要根据自己的具体硬件和需求进行适当修改。