用HC-SR501检测人接近1s以上，控制L9110风扇模块启动同时启动DHT11检测环境温度，根据温度自动调整风扇转速，人离开后关闭风扇，STM32F103ZET6生成代码

以下是基于STM32CubeMX和HAL库生成的代码，可以实现根据DHT11检测的温度自动调整风扇转速，并且在人离开后关闭风扇。

首先，需要在STM32CubeMX中配置以下外设和引脚：

- 时钟：使用外部晶振，主频为72MHz
- GPIO：PA0作为HC-SR501的信号输入，PB0和PB1分别作为L9110风扇模块的IN1和IN2输入，PC13作为人接近检测的LED指示灯输出
- TIM：使用TIM1作为PWM输出，配置PB13作为TIM1_CH1输出
- USART：使用USART1与DHT11通信，配置PA9作为USART1_TX输出，PA10作为USART1_RX输入

然后在STM32CubeMX中生成代码，并在main.c中添加以下代码（注释中有详细解释）：

#include "main.h"
#include "dht11.h"

// 定义HC-SR501的输入引脚
#define PIR_Pin GPIO_PIN_0
#define PIR_GPIO_Port GPIOA

// 定义L9110风扇模块的输入引脚和PWM输出引脚
#define IN1_Pin GPIO_PIN_0
#define IN1_GPIO_Port GPIOB
#define IN2_Pin GPIO_PIN_1
#define IN2_GPIO_Port GPIOB
#define PWM_Pin GPIO_PIN_13
#define PWM_GPIO_Port GPIOB

// 定义DHT11的输入输出引脚
#define DHT11_Pin GPIO_PIN_9
#define DHT11_GPIO_Port GPIOA

// 定义PWM输出的最大值和最小值
#define PWM_MAX_VALUE 10000
#define PWM_MIN_VALUE 0

// 定义DHT11读取数据的间隔时间
#define DHT11_READ_INTERVAL 2000

// 定义人接近检测的LED指示灯的闪烁时间
#define PIR_LED_BLINK_INTERVAL 200

// 定义变量保存当前温度和湿度
static uint8_t temperature = 0;
static uint8_t humidity = 0;

// 定义变量保存当前PWM输出值
static uint16_t pwm_value = PWM_MIN_VALUE;

// 定义变量保存上一次检测到人的时间
static uint32_t last_pir_time = 0;

// 定义变量保存上一次读取DHT11数据的时间
static uint32_t last_dht11_read_time = 0;

// 定义变量保存当前是否检测到人
static uint8_t is_pir_detected = 0;

// 定义变量保存当前LED指示灯是否亮着
static uint8_t is_pir_led_on = 0;

// 定义变量保存当前是否正在读取DHT11数据
static uint8_t is_dht11_reading = 0;

// 定义函数：初始化HC-SR501
void PIR_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOA_CLK_ENABLE();

  /*Configure GPIO pin : PIR_Pin */
  GPIO_InitStruct.Pin = PIR_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  HAL_GPIO_Init(PIR_GPIO_Port, &GPIO_InitStruct);
}

// 定义函数：初始化L9110风扇模块
void L9110_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOB_CLK_ENABLE();

  /*Configure GPIO pins : IN1_Pin IN2_Pin */
  GPIO_InitStruct.Pin = IN1_Pin|IN2_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

  /*Configure GPIO pin : PWM_Pin */
  GPIO_InitStruct.Pin = PWM_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  GPIO_InitStruct.Alternate = GPIO_AF1_TIM1;
  HAL_GPIO_Init(PWM_GPIO_Port, &GPIO_InitStruct);
}

// 定义函数：初始化定时器1作为PWM输出
void TIM1_PWM_Init(void)
{
  TIM_HandleTypeDef htim1 = {0};
  TIM_OC_InitTypeDef sConfigOC = {0};

  /* TIM1 clock enable */
  __HAL_RCC_TIM1_CLK_ENABLE();

  /* Configure TIM1: PWM */
  htim1.Instance = TIM1;
  htim1.Init.Prescaler = 0;
  htim1.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim1.Init.Period = PWM_MAX_VALUE;
  htim1.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  htim1.Init.RepetitionCounter = 0;
  HAL_TIM_PWM_Init(&htim1);

  /* Configure TIM1 OC */
  sConfigOC.OCMode = TIM_OCMODE_PWM1;
  sConfigOC.Pulse = PWM_MIN_VALUE;
  sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
  sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
  HAL_TIM_PWM_ConfigChannel(&htim1, &sConfigOC, TIM_CHANNEL_1);

  /* Start TIM1 PWM */
  HAL_TIM_PWM_Start(&htim1, TIM_CHANNEL_1);
}

// 定义函数：初始化DHT11
void DHT11_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOA_CLK_ENABLE();

  /*Configure GPIO pin : DHT11_Pin */
  GPIO_InitStruct.Pin = DHT11_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_OD;
  GPIO_InitStruct.Pull = GPIO_PULLUP;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(DHT11_GPIO_Port, &GPIO_InitStruct);

  /* Set DHT11 pin to high */
  HAL_GPIO_WritePin(DHT11_GPIO_Port, DHT11_Pin, GPIO_PIN_SET);
}

// 定义函数：检测HC-SR501是否检测到人
void PIR_Detect(void)
{
  if (HAL_GPIO_ReadPin(PIR_GPIO_Port, PIR_Pin) == GPIO_PIN_SET) {
    // 人接近
    last_pir_time = HAL_GetTick();
    if (!is_pir_detected) {
      // 之前没有检测到人，打开风扇和LED指示灯
      is_pir_detected = 1;
      is_pir_led_on = 1;
      HAL_GPIO_WritePin(IN1_GPIO_Port, IN1_Pin, GPIO_PIN_SET);
      HAL_GPIO_WritePin(IN2_GPIO_Port, IN2_Pin, GPIO_PIN_RESET);
    }
  } else {
    // 人离开
    if (HAL_GetTick() - last_pir_time > 1000) {
      // 已经离开超过1秒，关闭风扇和LED指示灯
      is_pir_detected = 0;
      is_pir_led_on = 0;
      HAL_GPIO_WritePin(IN1_GPIO_Port, IN1_Pin, GPIO_PIN_RESET);
      HAL_GPIO_WritePin(IN2_GPIO_Port, IN2_Pin, GPIO_PIN_RESET);
    } else {
      // 仍然在检测到人的时间内，保持风扇和LED指示灯状态不变
    }
  }
}

// 定义函数：读取DHT11数据
void DHT11_Read(void)
{
  if (!is_dht11_reading && HAL_GetTick() - last_dht11_read_time > DHT11_READ_INTERVAL) {
    // 当前没有在读取DHT11数据，并且间隔时间已经超过预设时间
    is_dht11_reading = 1;
    uint8_t data[5] = {0};
    if (DHT11_ReadData(data) == DHT11_OK) {
      // 读取数据成功，计算温度和湿度
      humidity = data[0];
      temperature = data[2];
    }
    is_dht11_reading = 0;
    last_dht11_read_time = HAL_GetTick();
  }
}

// 定义函数：根据温度调整PWM输出值
void PWM_Adjust(void)
{
  if (is_pir_detected) {
    // 人接近，根据温度调整PWM输出值
    if (temperature >= 30) {
      pwm_value = PWM_MAX_VALUE;
    } else if (temperature >= 25) {
      pwm_value = PWM_MAX_VALUE * 3 / 4;
    } else if (temperature >= 20) {
      pwm_value = PWM_MAX_VALUE * 1 / 2;
    } else {
      pwm_value = PWM_MAX_VALUE * 1 / 4;
    }
  } else {
    // 人离开，PWM输出值为最小值
    pwm_value = PWM_MIN_VALUE;
  }

  // 更新PWM输出值
  TIM_HandleTypeDef htim1 = {0};
  htim1.Instance = TIM1;
  TIM_OC_InitTypeDef sConfigOC = {0};
  sConfigOC.OCMode = TIM_OCMODE_PWM1;
  sConfigOC.Pulse = pwm_value;
  sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
  sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
  HAL_TIM_PWM_ConfigChannel(&htim1, &sConfigOC, TIM_CHANNEL_1);
  HAL_TIM_PWM_Start(&htim1, TIM_CHANNEL_1);
}

// 定义函数：控制LED指示灯闪烁
void PIR_LED_Blink(void)
{
  static uint32_t last_blink_time = 0;
  if (is_pir_led_on && HAL_GetTick() - last_blink_time > PIR_LED_BLINK_INTERVAL) {
    // LED指示灯亮着，并且闪烁时间已经超过预设时间
    is_pir_led_on = 0;
    HAL_GPIO_WritePin(PC13_GPIO_Port, PC13_Pin, GPIO_PIN_RESET);
  } else if (!is_pir_led_on && HAL_GetTick() - last_blink_time > PIR_LED_BLINK_INTERVAL) {
    // LED指示灯没亮，并且闪烁时间已经超过预设时间
    is_pir_led_on = 1;
    HAL_GPIO_WritePin(PC13_GPIO_Port, PC13_Pin, GPIO_PIN_SET);
  } else {
    // LED指示灯状态不变
  }
}

int main(void)
{
  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* Configure the system clock */
  SystemClock_Config();

  /* Initialize all configured peripherals */
  PIR_Init();
  L9110_Init();
  TIM1_PWM_Init();
  DHT11_Init();

  /* Infinite loop */
  while (1)
  {
    PIR_Detect();
    DHT11_Read();
    PWM_Adjust();
    PIR_LED_Blink();
    HAL_Delay(10);
  }
}

需要注意的是，以上代码中使用了DHT11库来读取DHT11的温度和湿度数据。DHT11库的代码可以自行搜索下载，也可以参考以下代码：

#include "dht11.h"

#define DHT11_DATA_HIGH_TIME 30
#define DHT11_DATA_LOW_TIME 80
#define DHT11_ACK_HIGH_TIME 80
#define DHT11_ACK_LOW_TIME 80

static void DHT11_Delay(uint32_t ms)
{
  HAL_Delay(ms);
}

static void DHT11_SetPinOutput(GPIO_TypeDef *GPIOx, uint16_t GPIO_Pin)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};
  GPIO_InitStruct.Pin = GPIO_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_PULLUP;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOx, &GPIO_InitStruct);
}

static void DHT11_SetPinInput(GPIO_TypeDef *GPIOx, uint16_t GPIO_Pin)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};
  GPIO_InitStruct.Pin = GPIO_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  HAL_GPIO_Init(GPIOx, &GPIO_InitStruct);
}

static uint8_t DHT11_ReadByte(void)
{
  uint8_t data = 0;
  for (uint8_t i = 0; i < 8; i++) {
    while (HAL_GPIO_ReadPin(DHT11_GPIO_Port, DHT11_Pin) == GPIO_PIN_RESET);
    DHT11_Delay(DHT11_DATA_HIGH_TIME);
    if (HAL_GPIO_ReadPin(DHT11_GPIO_Port, DHT11_Pin) == GPIO_PIN_SET) {
      data |= 1 << (7 - i);
    }
    while (HAL_GPIO_ReadPin(DHT11_GPIO_Port, DHT11_Pin) == GPIO_PIN_SET);
  }
  return data;
}

static uint8_t DHT11_ReadData(uint8_t data[5])
{
  // 发送起始信号
  DHT11_SetPinOutput(DHT11_GPIO_Port, DHT11_Pin);
  HAL_GPIO_WritePin(DHT11_GPIO_Port, DHT11_Pin, GPIO_PIN_RESET);
  DHT11_Delay(18);
  HAL_GPIO_WritePin(DHT11_GPIO_Port, DHT11_Pin, GPIO_PIN_SET);
  DHT11_Delay(1);
  DHT11_SetPinInput(DHT11_GPIO_Port, DHT11_Pin);

  // 等待DHT11响应
  uint32_t timeout = DHT11_ACK_HIGH_TIME;
  while (HAL_GPIO_ReadPin(DHT11_GPIO_Port, DHT11_Pin) == GPIO_PIN_RESET && timeout--);
  if (timeout == 0) {
    return DHT11_TIMEOUT_ERROR;
  }
  timeout = DHT11_ACK_LOW_TIME;
  while (HAL_GPIO_ReadPin(DHT11_GPIO_Port, DHT11_Pin) == GPIO_PIN_SET && timeout--);
  if (timeout == 0) {
    return DHT11_TIMEOUT_ERROR;
  }

  // 读取数据
  for (uint8_t i = 0; i < 5; i++) {
    data[i] = DHT11_ReadByte();
  }

  // 计算校验和
  if (data[0] + data[1] + data[2] + data[3] != data[4]) {
    return DHT11_CHECKSUM_ERROR;
  }

  return DHT11_OK;
}