编写dht11温湿度传感器的stm32程序

以下是使用STM32的HAL库编写DHT11温湿度传感器程序的示例代码：

#include "stm32f4xx_hal.h"

#define DHT11_PORT GPIOA
#define DHT11_PIN GPIO_PIN_0

TIM_HandleTypeDef htim2;

void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_TIM2_Init(void);

int main(void)
{
  HAL_Init();
  SystemClock_Config();
  MX_GPIO_Init();
  MX_TIM2_Init();

  while (1)
  {
    // 等待 1s
    HAL_Delay(1000);

    // 发送开始信号
    HAL_GPIO_WritePin(DHT11_PORT, DHT11_PIN, GPIO_PIN_RESET);
    HAL_Delay(20);
    HAL_GPIO_WritePin(DHT11_PORT, DHT11_PIN, GPIO_PIN_SET);
    HAL_Delay(30);

    // 接收数据
    uint8_t buffer[5] = {0};
    uint8_t bit_count = 0;
    uint8_t byte_count = 0;
    uint8_t data = 0;

    for (int i = 0; i < 40; i++)
    {
      // 等待下一位数据的到来
      while (!HAL_GPIO_ReadPin(DHT11_PORT, DHT11_PIN));

      // 计时，以确定数据位是 0 还是 1
      TIM2->CNT = 0;
      while (HAL_GPIO_ReadPin(DHT11_PORT, DHT11_PIN));
      uint16_t time = TIM2->CNT;

      if (time > 40)
      {
        // 数据位为 1
        data |= (uint8_t)(1 << (7 - bit_count));
      }

      bit_count++;
      if (bit_count == 8)
      {
        buffer[byte_count] = data;
        byte_count++;
        data = 0;
        bit_count = 0;
      }
    }

    // 验证校验和
    if (buffer[4] == (buffer[0] + buffer[1] + buffer[2] + buffer[3]))
    {
      // 计算温度和湿度
      uint16_t humidity = ((uint16_t)buffer[0] << 8) | buffer[1];
      uint16_t temperature = ((uint16_t)buffer[2] << 8) | buffer[3];

      // 输出温度和湿度
      float h = (float)humidity / 10.0f;
      float t = (float)temperature / 10.0f;
      printf("Humidity: %.1f%% Temperature: %.1fC\r\n", h, t);
    }
    else
    {
      printf("Checksum error!\r\n");
    }
  }
}

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

  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  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();
  }

  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_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  __HAL_RCC_GPIOA_CLK_ENABLE();

  GPIO_InitStruct.Pin = DHT11_PIN;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_PULLUP;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(DHT11_PORT, &GPIO_InitStruct);
}

static void MX_TIM2_Init(void)
{
  TIM_ClockConfigTypeDef sClockSourceConfig = {0};
  TIM_MasterConfigTypeDef sMasterConfig = {0};

  __HAL_RCC_TIM2_CLK_ENABLE();

  htim2.Instance = TIM2;
  htim2.Init.Prescaler = 100 - 1;
  htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim2.Init.Period = 65535;
  htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  if (HAL_TIM_Base_Init(&htim2) != HAL_OK)
  {
    Error_Handler();
  }

  sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
  if (HAL_TIM_ConfigClockSource(&htim2, &sClockSourceConfig) != HAL_OK)
  {
    Error_Handler();
  }

  sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
  if (HAL_TIMEx_MasterConfigSynchronization(&htim2, &sMasterConfig) != HAL_OK)
  {
    Error_Handler();
  }
}

请注意，此代码仅供参考，您应该根据您的具体硬件和需求进行修改。在编写自己的程序之前，请确保您已经正确地连接了DHT11传感器。