DS18B20 nin hatalı okuma sorunu ?

 
  //*************************************************************************************** 
  unsigned char DS18B20_init(void) { 
  	unsigned char sonuc; 
  	DS18B20_PinYon = 0; 
  	DS18B20_Pin = 0; 
  	DelayUs(490);		// > 480us 
  	DS18B20_PinYon = 1; 
  	DelayUs(65);		// > 60us 
  	sonuc = DS18B20_Pin;	// 0 Hazır, 1 Hazır değil 
  	DelayUs(400); 
  	return sonuc; 
  } 
  unsigned int DS18B20_Oku(void) { 
  	unsigned char sayac; 
  	unsigned int veri, bitler; 
  	veri=0; bitler=1; 
  	for (sayac=0; sayac<16; sayac++) { 
  		DS18B20_Pin=0; DS18B20_PinYon=0; DelayUs(1); DS18B20_PinYon=1; 
  		if ( DS18B20_Pin==1 ) veri|=bitler; 
  		DelayUs(60); bitler=bitler<<1; 
  	} 
  	return veri; 
  } 
  void DS18B20_Yaz(unsigned char veri) { 
  	unsigned char bitler, sayac; 
  	bitler = 1; 
  	for (sayac=0;sayac<8;sayac++) { 
  		if ( veri&bitler) { 
  			DS18B20_PinYon=0; DS18B20_Pin=0; DelayUs(3); DS18B20_PinYon=1; DelayUs(60); 
  		} else { 
  			DS18B20_PinYon=0; DS18B20_Pin=0; DelayUs(60); DS18B20_PinYon=1; 
  		} 
  		bitler=bitler<<1; 
  	} 
  } 
   
  void SicaklikOku(void) { 
  	unsigned char sayac, bitlertam, bitleronda; 
  	unsigned int sicaklik, bitler; 
  	DS18B20_PinYon = 0; 
  Tekrar: 
  	if ( DS18B20_init()==1 ) goto Tekrar; 
  	DS18B20_Yaz(0xCC); DS18B20_Yaz(0x44); 
  	DelayMs(250); DelayMs(250); DelayMs(250); 
  	if ( DS18B20_init()==1 ) goto Tekrar; 
  	DS18B20_Yaz(0xCC); DS18B20_Yaz(0xBE); 
  	sicaklik=DS18B20_Oku(); 
  	bitler=1; bitlertam=1; bitleronda=1; 
  	OrtamSicaklik=0; OrtamSicaklikOnda=0; 
  	for (sayac=0;sayac<12;sayac++) { 
  		if (sayac<4) { 
  			if (sicaklik&bitler) OrtamSicaklikOnda=OrtamSicaklikOnda|bitleronda; 
  			bitleronda=bitleronda<<1; 
  		} else { 
  			if (sicaklik&bitler) OrtamSicaklik=OrtamSicaklik|bitlertam; 
  			bitlertam=bitlertam<<1; 
  		} 
  		bitler=bitler<<1; 
  	} 
  	OrtamSicaklikOnda = (OrtamSicaklikOnda * 625) / 1000; 
  }