stm32f103c8t6温湿度dht11教程

好的，下面是STM32F103C8T6与DHT11温湿度传感器的教程。

1. 硬件连接：

将DHT11的VCC引脚连接到STM32F103C8T6开发板的3.3V电源引脚，GND引脚连接到开发板的GND引脚，DATA引脚连接到开发板的任意一个GPIO引脚。

2. 软件编程：

首先需要在工程中调用STM32F1xx_HAL_Driver库，并在代码中定义相应的引脚号。

接下来，需要编写相应的程序代码读取DHT11传感器的数据。具体步骤如下：

(1) 通过GPIO口输出低电平信号，保持至少18ms以上（一般为20ms）。

(2) 将GPIO口输出高电平信号，并延时20us，再将GPIO口设置为输入模式。

(3) 等待DHT11的响应信号，即DHT11会将总线拉低80us，然后再拉高80us。

(4) 接下来，DHT11会输出40个数据位，每个数据位之间的低电平时间为50us，高电平时间为26-28us。0表示低电平时长为26-28us，高电平时长为50us；1表示低电平时长为50us，高电平时长为26-28us。

(5) 最后，DHT11会输出一个总线释放信号，即拉高总线80us。

3. 完整代码实现：

#include "main.h"

TIM_HandleTypeDef htim2;

void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_TIM2_Init(void);
void delay_us(uint32_t us);
void DHT11_start(void);
uint8_t DHT11_read_byte(void);
uint8_t DHT11_read_data(uint8_t *temp, uint8_t *humi);

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

  uint8_t temp = 0, humi = 0;
  while (1)
  {
    if (DHT11_read_data(&temp, &humi) == HAL_OK)
    {
      printf("Temperature: %d, Humidity: %d\n", temp, humi);
    }
    else
    {
      printf("Error reading data from DHT11\n");
    }
    HAL_Delay(2000);
  }
}

void DHT11_start(void)
{
  HAL_GPIO_WritePin(GPIOA, GPIO_PIN_1, GPIO_PIN_RESET);
  delay_us(20000); // hold the GPIO pin to reset the DHT11
  HAL_GPIO_WritePin(GPIOA, GPIO_PIN_1, GPIO_PIN_SET);
  delay_us(20);
  HAL_GPIO_WritePin(GPIOA, GPIO_PIN_1, GPIO_PIN_RESET);
}

uint8_t DHT11_read_byte(void)
{
  uint8_t i, j;
  uint8_t byte = 0;
  for (i = 0; i < 8; i++)
  {
    while (HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_1) == GPIO_PIN_RESET)
      ; // wait for the start of low pulse
    delay_us(30);                                                // delay 30us to read the data bit
    if (HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_1) == GPIO_PIN_SET)     // if the data bit is high
      byte |= (1 << (7 - i));                                     // set the corresponding bit in byte
    while (HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_1) == GPIO_PIN_SET)  // wait for the end of data bit
      ;
  }
  return byte;
}

uint8_t DHT11_read_data(uint8_t *temp, uint8_t *humi)
{
  DHT11_start();
  if (HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_1) == GPIO_PIN_RESET)  // if DHT11 responds
  {
    while (HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_1) == GPIO_PIN_RESET)
      ; // wait for the end of low pulse
    while (HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_1) == GPIO_PIN_SET)
      ;                                                // wait for the end of high pulse
    *humi = DHT11_read_byte();                          // read humidity byte
    uint8_t humi_verify = DHT11_read_byte();            // read humidity verify byte
    *temp = DHT11_read_byte();                          // read temperature byte
    uint8_t temp_verify = DHT11_read_byte();            // read temperature verify byte
    uint8_t sum = DHT11_read_byte();                     // read the sum byte

    if (sum == (*humi + humi_verify + *temp + temp_verify))
      return HAL_OK;
    else
      return HAL_ERROR;
  }
  else
    return HAL_ERROR;
}

void delay_us(uint32_t us)
{
  __HAL_TIM_SET_COUNTER(&htim2, 0);
  while (__HAL_TIM_GET_COUNTER(&htim2) < us)
    ;
}

void MX_TIM2_Init(void)
{

  TIM_ClockConfigTypeDef sClockSourceConfig = {0};
  TIM_MasterConfigTypeDef sMasterConfig = {0};

  htim2.Instance = TIM2;
  htim2.Init.Prescaler = (SystemCoreClock / 1000000) - 1;
  htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim2.Init.Period = 0xFFFF;
  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();
  }
}

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

  __HAL_RCC_GPIOA_CLK_ENABLE();

  GPIO_InitStruct.Pin = GPIO_PIN_1;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_OD;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  printf("GPIO initialized\n");
}

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

  /** 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();
  }
}

在本示例代码中，我们将DHT11数据线连接到PA1引脚，将时钟源设置为HSI。在主循环中，我们每2秒钟读一次DHT11数据，并将温度和湿度打印到串口终端。

最后，使用ST-Link将生成的代码烧写到STM32F103C8T6开发板上即可。