Well let me give this a shot. Short and sweet. You need a one-wire sensor. Let's start with a temperature sensor DS18s20. It has three legs. You need 2 wires, not one, and most recommend cat5 because of the twisted pairs are better for the one wire signal. Then you need a computer interface. There are several approaches but some of them are either a DS9097u, a LINK, a USB connector (can remember the part number, or a temp05/08 unit. The difference between the temp05/08 unit and the rest is the temp05/08 unit processes the reading of the one-wire "bus" for you. The other interfaces use the PC to process the data. Lastly you need software to read the incoming data. The Temp0508 unit come with a script that can be used to populate HomeSeer devices and there also the DooTemp08 plugin. The others need software and this has been scarce on the HS BB. There used to be a pretty good plugin that would read data from a DS9097U but it died. I believe Michael McSherry wrote an xAP application that can read them and If I remember correctly several of his other MCS apps read the DS9097U. What I would love to see is a simple script/plugin to read the one wire devices but apparently it's not as easy as it appears. The beauty of the system is hypothetically you can tap into the cat5 wire at any point and add a new sensor. All of the one-wire sensors use the same 2 wires in "parasitic" mode and the same 3 wires in an external power mode. For example in the parasitic mode 2 of the wires are connected which leaves the 2 wires needed to form the "one-wire" connections. On a temp sensor the outer 2 wires (GND and Vdd) are connected together. I do not want to get too technical and to tell you the truth if an engineering challenged person like me can do this anyone can.
