DHT11 AND ESP8266

#define DHT D4
uint8_t DHTbuf[5]; 
uint8_t error;

uint8_t readDHT(){
  error=false;
  pinMode(DHT,OUTPUT);
  digitalWrite(DHT, LOW); 
  delay(2);
  digitalWrite(DHT, HIGH); 
  delayMicroseconds(40);
  pinMode(DHT,INPUT_PULLUP);
  waitLow();
  if(error){     //is sensor pulling low
    Serial.println("DHT not present");
    return false;             //no, so return
  }
  uint8_t i,j;
  waitHigh();
  waitLow();
  for(i=0;i<5;i++){
    for(j=0;j<8;j++){
      waitHigh();
      delayMicroseconds(40);
      DHTbuf[i]<<=1;
      if(digitalRead(DHT)==1)
        DHTbuf[i]++;
      waitLow();
    }
  }
  uint8_t sum = DHTbuf[0] + DHTbuf[1] + DHTbuf[2] + DHTbuf[3];
  if (DHTbuf[4] != sum) 
    return false;
  return !error;
}

void waitLow(){
  if(error)
    return;
  uint16_t timeout=2000;
  while(digitalRead(DHT)==1 && --timeout>0);
  if(timeout>0)
    return;
  error=true;
}

void waitHigh(){
  uint16_t timeout=2000;
  if(error)
    return;
  while(digitalRead(DHT)==0 && --timeout>0);
  if(timeout>0)
    return;
  error=true;
}