51驱动DHT12

以下是一个使用51单片机驱动DHT12的简单示例代码：

#include <reg52.h>
#include <intrins.h>
#include <stdio.h>
#include <stdlib.h>

#define DHT12_I2C_ADDRESS 0x5C

typedef unsigned char uint8_t;
typedef unsigned int uint16_t;

sbit SDA=P1^1;
sbit SCL=P1^0;

void delay_us(unsigned int us)
{
    while(us--)
    {
        _nop_();
    }
}

void I2C_start()
{
    SDA = 1;
    SCL = 1;
    delay_us(5);
    SDA = 0;
    delay_us(5);
    SCL = 0;
}

void I2C_stop()
{
    SDA = 0;
    SCL = 1;
    delay_us(5);
    SDA = 1;
    delay_us(5);
}

uint8_t I2C_write_byte(uint8_t dat)
{
    uint8_t i, ack;
    for(i=0; i<8; i++)
    {
        SDA = (dat & 0x80) ? 1 : 0;
        dat <<= 1;
        delay_us(5);
        SCL = 1;
        delay_us(5);
        SCL = 0;
    }
    SDA = 1;
    delay_us(5);
    SCL = 1;
    ack = SDA;
    delay_us(5);
    SCL = 0;

    return ack;
}

uint8_t I2C_read_byte()
{
    uint8_t i, dat = 0;
    SDA = 1;
    for(i=0; i<8; i++)
    {
        delay_us(5);
        SCL = 1;
        dat <<= 1;
        dat |= SDA;
        delay_us(5);
        SCL = 0;
    }
    return dat;
}

void DHT12_read_data(uint8_t *data)
{
    uint8_t i;
    I2C_start();
    I2C_write_byte(DHT12_I2C_ADDRESS << 1);
    I2C_write_byte(0x00);

    I2C_start();
    I2C_write_byte((DHT12_I2C_ADDRESS << 1) + 1);

    for(i=0; i<5; i++)
    {
        data[i] = I2C_read_byte();
    }

    I2C_stop();
}

void main()
{
    uint8_t data[5];
    uint16_t temperature, humidity;

    while(1)
    {
        DHT12_read_data(data);

        temperature = (data[2] << 8) | data[3];
        temperature /= 10;

        humidity = (data[0] << 8) | data[1];
        humidity /= 10;

        printf("Temperature: %dC, Humidity: %d%%\n", temperature, humidity);

        delay_ms(2000);
    }
}

这个示例代码使用了51单片机的GPIO来模拟I2C总线，读取DHT12传感器的温度和湿度值，并通过串口输出。请将DHT12连接到51单片机的SDA和SCL引脚上，然后下载代码到单片机上进行测试。