myhome_dht

#include <wiringPi.h>
#include <stdio.h>
#include <stdint.h>
#include <time.h>

#define DHTPIN 7
#define MAXTIMING 85

int data[5] = {0,0,0,0,0};
char buff[20];

int read_dht11(){

    uint8_t laststate = HIGH;
    uint8_t counter = 0;
    uint8_t i = 0, j = 0;
    float f;

    data[0] = data[1] = data[2] = data[3] = data[4] = 0;

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

    for(i=0;i<MAXTIMING;i++){

        counter = 0;

        while(digitalRead(DHTPIN) == laststate){

            counter++;
            delayMicroseconds(1);
            if(counter == 255){
                break;
            }
        }

        laststate = digitalRead(DHTPIN);

        if(counter == 255){
            break;
        }

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

    }

    if((j >= 40) && (data[4] == ((data[0] + data[1] + data[2] + data[3]) & 0xFF))){

        f = data[2] * 9. / 5. + 32;
        printf("Humidity = %d.%d %%, Temperature = %d.%d *C (%.1f *F)\n",
            data[0], data[1], data[2], data[3], f);

        FILE* f;
        f = fopen("result.csv", "w");

        time_t now = time(NULL);
        strftime(buff, 20, "%Y%m%d%H%M%S", localtime(&now));

        if(data[2] > 50){
            return;
        }

        fprintf(f, "%s,%d.%d,%d.%d\n", buff, data[0], data[1], data[2], data[3], f);

        fclose(f);
        return 1;

    }else{
        printf("failed..\n");
    }

    return 0;


}


int main(){

    if(wiringPiSetup() == -1){
        printf("error");
    }

    while(!read_dht11()){
        delayMicroseconds(500 * 1000);
    }

}