生成stm32的DHT11代码

以下是基于STM32 HAL库的DHT11驱动代码示例：

#include "stm32f4xx_hal.h"

#define DHT11_PORT GPIOA
#define DHT11_PIN GPIO_PIN_0

void delay_us(uint32_t us)
{
    uint32_t count = us * (SystemCoreClock / 1000000) / 5;
    while(count--);
}

void DHT11_Start(void)
{
    HAL_GPIO_WritePin(DHT11_PORT, DHT11_PIN, GPIO_PIN_RESET);
    delay_us(18000);
    HAL_GPIO_WritePin(DHT11_PORT, DHT11_PIN, GPIO_PIN_SET);
    delay_us(20);
    HAL_GPIO_WritePin(DHT11_PORT, DHT11_PIN, GPIO_PIN_RESET);
}

uint8_t DHT11_Check(void)
{
    uint8_t response = 1;
    uint16_t count = 0;
    while(HAL_GPIO_ReadPin(DHT11_PORT, DHT11_PIN) == GPIO_PIN_SET)
    {
        count++;
        if(count > 10000)
        {
            response = 0;
            break;
        }
    }
    return response;
}

uint8_t DHT11_Read_Bit(void)
{
    uint8_t response = 1;
    uint16_t count = 0;
    while(HAL_GPIO_ReadPin(DHT11_PORT, DHT11_PIN) == GPIO_PIN_RESET)
    {
        count++;
        if(count > 10000)
        {
            response = 0;
            break;
        }
    }
    delay_us(40);
    if(HAL_GPIO_ReadPin(DHT11_PORT, DHT11_PIN) == GPIO_PIN_SET)
    {
        response = 1;
    }
    else
    {
        response = 0;
    }
    count = 0;
    while(HAL_GPIO_ReadPin(DHT11_PORT, DHT11_PIN) == GPIO_PIN_SET)
    {
        count++;
        if(count > 10000)
        {
            response = 0;
            break;
        }
    }
    return response;
}

uint8_t DHT11_Read_Byte(void)
{
    uint8_t i, temp = 0;
    for(i = 0; i < 8; i++)
    {
        temp |= (DHT11_Read_Bit() << (7 - i));
    }
    return temp;
}

uint8_t DHT11_Read_Data(uint8_t *humidity, uint8_t *temperature)
{
    uint8_t response = 0;
    uint8_t buffer[5];
    DHT11_Start();
    if(DHT11_Check() == 0)
    {
        response = 1;
        buffer[0] = DHT11_Read_Byte();
        buffer[1] = DHT11_Read_Byte();
        buffer[2] = DHT11_Read_Byte();
        buffer[3] = DHT11_Read_Byte();
        buffer[4] = DHT11_Read_Byte();
        if(buffer[4] == (buffer[0] + buffer[1] + buffer[2] + buffer[3]))
        {
            *humidity = buffer[0];
            *temperature = buffer[2];
        }
        else
        {
            response = 2;
        }
    }
    return response;
}

使用方法：

1. 在`main.c`文件中添加上述代码。
2. 在`main`函数中调用`DHT11_Read_Data`函数，读取温湿度数据。

示例代码：

#include "stm32f4xx_hal.h"

uint8_t humidity, temperature;

int main(void)
{
    HAL_Init();
    /* 初始化GPIO */
    GPIO_InitTypeDef GPIO_InitStruct;
    __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_HIGH;
    HAL_GPIO_Init(DHT11_PORT, &GPIO_InitStruct);
    HAL_GPIO_WritePin(DHT11_PORT, DHT11_PIN, GPIO_PIN_RESET);

    /* 读取温湿度数据 */
    uint8_t response = DHT11_Read_Data(&humidity, &temperature);
    if(response == 0)
    {
        /* 温湿度数据读取成功 */
        printf("湿度：%d%%，温度：%d℃\n", humidity, temperature);
    }
    else if(response == 1)
    {
        /* DHT11无响应 */
        printf("DHT11无响应\n");
    }
    else if(response == 2)
    {
        /* 校验和错误 */
        printf("校验和错误\n");
    }
    while(1);
}