Interface DHT11 with Arduino

Have got hold of a DHT 11 humidity sensor that outputs a digital signal to indicate temperature and humidty.

However seem to be having a few issues trying to get a pic to communicate successfully, and retrieve the data, and then display it on an lcd

I am using an 18f4550, and have some sample code for an Arduino, but am unable to convert it.

I have attached the sample code below.

Code: Select all

#define DHT11_PIN 0      // ADC0

byte read_dht11_dat()
{
   byte i = 0;
   byte result=0;
   for(i=0; i< 8; i++){
      
      
      while(!(PINC & _BV(DHT11_PIN)));  // wait for 50us
      delayMicroseconds(30);
      
      if(PINC & _BV(DHT11_PIN)) 
         result |=(1<<(7-i));
              while((PINC & _BV(DHT11_PIN)));  // wait '1' finish
         
      
   }
   return result;
}


void setup()
{
   DDRC |= _BV(DHT11_PIN);
   PORTC |= _BV(DHT11_PIN);
   
     Serial.begin(19200);
  
Serial.println("Ready");
   }
   
void loop()
{
   byte dht11_dat[5];
   byte dht11_in;
   byte i;
   // start condition
   // 1. pull-down i/o pin from 18ms
   PORTC &= ~_BV(DHT11_PIN);
   delay(18);
   PORTC |= _BV(DHT11_PIN);
   delayMicroseconds(40);
   
   DDRC &= ~_BV(DHT11_PIN);
   delayMicroseconds(40);
   
   dht11_in = PINC & _BV(DHT11_PIN);
   
   if(dht11_in){
      Serial.println("dht11 start condition 1 not met");
      return;
   }
   delayMicroseconds(80);
   
   dht11_in = PINC & _BV(DHT11_PIN);
   
   if(!dht11_in){
      Serial.println("dht11 start condition 2 not met");
      return;
   }
   delayMicroseconds(80);
   // now ready for data reception
   for (i=0; i<5; i++)
      dht11_dat[i] = read_dht11_dat();
      
   DDRC |= _BV(DHT11_PIN);
   PORTC |= _BV(DHT11_PIN);
   
        byte dht11_check_sum = dht11_dat[0]+dht11_dat[1]+dht11_dat[2]+dht11_dat[3];
   // check check_sum
   if(dht11_dat[4]!= dht11_check_sum)
   {
      Serial.println("DHT11 checksum error");
   }
   
   Serial.print("Current humdity = ");
   Serial.print(dht11_dat[0], DEC);
   Serial.print(".");
   Serial.print(dht11_dat[1], DEC);
   Serial.print("%  ");
   Serial.print("temperature = ");
   Serial.print(dht11_dat[2], DEC);
   Serial.print(".");
   Serial.print(dht11_dat[3], DEC);
   Serial.println("C  ");
   
   delay(2000);
}



Could anyone offer any suggestions ?

P.S Link for data sheet http://www.aosong.com/english/Upload/PicFiles/20091281822579047.pdf

thanks 

Link : http://www.mikroe.com/forum/viewtopic.php?f=88&t=25475