The DS18B20Solo.zip file below contains an Arduino library that simplifies using a OneWire Dallas Temperature sensor when there is only one sensor attached to a digital pin on the Arduino. It only implements reading a single temperature but can be used with single sensors attached to two or more pins. There is no need to figure out the device address and if a sensor goes bad it can be replaced without changing the Arduino code to reflect the newer sensors unique address. Check out the examples provided. There is one for reading a single sensor and another for reading two sensors each on a different pin.