Probably two magnets a bridge type Hall sensor and one or two A/D channels. And a thermistor. You are trying to resolve ~0.3 degrees. That would require an optical encoder with multiplying gear (expen$ive) or a very expen$ive linear pot. The Hall sensor solution will likely be cheaper than both. You can also use a rotating vane capacitive sensor. Peter -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics