用C++写stm32控制的环境湿度检测系统代码

以下是一个简单的例子，使用STM32F103C8T6开发板和DHT11温湿度传感器。该代码使用STM32的定时器来生成精确的时间延迟，并使用GPIO口控制DHT11传感器。

#include "stm32f10x.h"

#define DHT11_GPIO GPIOA
#define DHT11_PIN GPIO_Pin_0

void delay_us(uint32_t us)
{
    SysTick->LOAD = 9 * us;
    SysTick->VAL = 0;
    SysTick->CTRL = SysTick_CTRL_CLKSOURCE_Msk | SysTick_CTRL_ENABLE_Msk;

    while (!(SysTick->CTRL & SysTick_CTRL_COUNTFLAG_Msk));

    SysTick->CTRL = 0;
}

void delay_ms(uint32_t ms)
{
    while (ms--) {
        delay_us(1000);
    }
}

void dht11_send_start(void)
{
    GPIO_InitTypeDef GPIO_InitStruct;

    GPIO_InitStruct.GPIO_Pin = DHT11_PIN;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;

    GPIO_Init(DHT11_GPIO, &GPIO_InitStruct);

    GPIO_ResetBits(DHT11_GPIO, DHT11_PIN);
    delay_ms(18);
    GPIO_SetBits(DHT11_GPIO, DHT11_PIN);
    delay_us(30);
}

uint8_t dht11_receive_bit(void)
{
    uint8_t bit = 0;

    GPIO_InitTypeDef GPIO_InitStruct;

    GPIO_InitStruct.GPIO_Pin = DHT11_PIN;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IPU;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;

    GPIO_Init(DHT11_GPIO, &GPIO_InitStruct);

    if (GPIO_ReadInputDataBit(DHT11_GPIO, DHT11_PIN) == Bit_RESET) {
        delay_us(50);

        if (GPIO_ReadInputDataBit(DHT11_GPIO, DHT11_PIN) == Bit_SET) {
            bit = 1;
        }
    }

    while (GPIO_ReadInputDataBit(DHT11_GPIO, DHT11_PIN) == Bit_SET);

    return bit;
}

uint8_t dht11_receive_byte(void)
{
    uint8_t byte = 0;

    for (int i = 0; i < 8; i++) {
        byte <<= 1;
        byte |= dht11_receive_bit();
    }

    return byte;
}

void dht11_receive_data(uint8_t* humidity, uint8_t* temperature)
{
    dht11_send_start();

    uint8_t data[5] = {0};
    for (int i = 0; i < 5; i++) {
        data[i] = dht11_receive_byte();
    }

    if (data[0] + data[1] + data[2] + data[3] == data[4]) {
        *humidity = data[0];
        *temperature = data[2];
    }
}

int main(void)
{
    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
    SysTick_Config(SystemCoreClock / 1000000);

    uint8_t humidity = 0, temperature = 0;

    while (1) {
        dht11_receive_data(&humidity, &temperature);

        // Do something with humidity and temperature values

        delay_ms(1000);
    }
}

注意：该代码仅提供了一个参考实现，实际应用中可能需要根据具体情况进行更改和优化。