1-Wire devices, such as the DS18B20 digital temperature sensor, are great to use with Arduino boards because you can connect many of them to a single IO pin. The freely available software libraries and example code make using 1-wire devices simple. There is only one problem we have seen with the examples on the web. If you have more than one device connected to a single pin, say an indoor temperature sensor, as well as an outdoor temperature sensor, how does your Arduino know which is which?
Using the tutorial at http://www.hacktronics.com/Tutorials/arduino-1-wire-address-finder.html, We determined the following on our two DS18B20 Temp Sensors:
0x28, 0x3C, 0xF2, 0xA7, 0x02, 0x00, 0x00, 0xCB
0x28, 0x20, 0x04, 0xA8, 0x02, 0x00, 0x00, 0x4D
Now we are ready to move forward with the indoor/outdoor temperature monitor. To be continued ...