There are several 1-wire app notes, make sure you read them all carefully. I just finished a design using the 1-wire bus. It started out as "just connect the temp sensor and plug in the sample code," but nothing is ever as easy as it seems. Our application required cable lengths of up to 1000 feet, but the device limitation is 50 feet. There is an app note that describes how to actively drive the bus longer distances. There is a sample circuit, followed by a statement something like "You also need a comparator circuit, which isn't shown here."

My next project is also a 1-wire simulator so we can test the control software without having to put the sensors in ice-water or hot coffee.

-- Tom Bachmann