DHT11

#include <wiringPi.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string>
#include <iostream>
#define MAX_TIME 85
#define DHT11PIN 7
int dht11_val[5]={0,0,0,0,0};
int humid;
int temp;
std::string dht11="";

void dht11_read_val()
{
  uint8_t lststate=HIGH;
  uint8_t counter=0;
  uint8_t 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))) {
    temp = dht11_val[2];
    humid = dht11_val[0];
    dht11=temp + ";" + humid;
  }
  else
    dht11="";
}

int main(void)
{
  if(wiringPiSetup()==-1)
    exit(1);
  while(dht11 != "")
  {
     dht11_read_val();
     if (dht11 != "")
     delay(3000);
  }
  //printf(dht11);
  std::cout << dht11 << std::endl;
  return 0;
}