树莓派dht11代码C语言代码

以下是树莓派上使用wiringPi库读取DHT11传感器数据的C语言代码：

#include <stdio.h>
#include <stdlib.h>
#include <wiringPi.h>

#define MAX_TIME 85
#define DHT11PIN 7

int dht11_val[5]={0,0,0,0,0};

void dht11_read_val()
{
    unsigned char lststate=HIGH;
    unsigned char counter=0;
    unsigned char j=0,i;

    for(i=0;i<5;i++)
        dht11_val[i]=0;

    pinMode(DHT11PIN,OUTPUT);
    digitalWrite(DHT11PIN,LOW);
    delay(18);
    digitalWrite(DHT11PIN,HIGH);
    delayMicroseconds(40);
    pinMode(DHT11PIN,INPUT);

    for(i=0;i<MAX_TIME;i++)
    {
        counter=0;
        while(digitalRead(DHT11PIN)==lststate)
        {
            counter++;
            delayMicroseconds(1);
            if(counter==255)
                break;
        }

        lststate=digitalRead(DHT11PIN);

        if(counter==255)
            break;

        if((i>=4)&&(i%2==0))
        {
            dht11_val[j/8]<<=1;
            if(counter>16)
                dht11_val[j/8]|=1;
            j++;
        }
    }

    if((j>=40)&&(dht11_val[4]==((dht11_val[0]+dht11_val[1]+dht11_val[2]+dht11_val[3])& 0xff)))
        printf("Humidity = %d.%d %% Temperature = %d.%d *C\n",dht11_val[0],dht11_val[1],dht11_val[2],dht11_val[3]);
    else
        printf("Invalid Data!!\n");
}

int main(void)
{
    if(wiringPiSetup()==-1)
        exit(1);

    while(1)
    {
        dht11_read_val();
        delay(5000);
    }

    return 0;
}

该代码通过wiringPi库中的GPIO控制函数，读取DHT11传感器的输出，实现了温湿度的测量。在主函数中，通过循环执行dht11_read_val()函数，实现了每隔五秒钟测量一次温湿度的功能。