树莓派dht11代码qt代码

以下是在Qt中使用wiringPi库读取DHT11传感器数据的C++代码：

#include <wiringPi.h>
#include <iostream>
#include <QCoreApplication>
#include <QTimer>

using namespace std;

#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<85;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)))
        cout << "Humidity = " << dht11_val[0] << "." << dht11_val[1] << " % Temperature = " << dht11_val[2] << "." << dht11_val[3] << " *C" << endl;
    else
        cout << "Invalid Data!!" << endl;
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    if(wiringPiSetup()==-1)
        exit(1);

    QTimer timer;
    QObject::connect(&timer, &QTimer::timeout, dht11_read_val);
    timer.start(5000); // 5000ms执行一次

    return a.exec();
}

该代码在Qt中通过QTimer定时器，实现了每隔五秒钟读取一次DHT11传感器的温湿度数据。在主函数中，通过连接定时器的timeout信号和dht11_read_val()槽函数，实现了定时执行读取数据的操作。在dht11_read_val()函数中，同样通过wiringPi库中的GPIO控制函数，读取DHT11传感器的输出，并将温湿度数据打印到控制台上。