Elk - Temperture Sensor - Do you needs to use their sensor?

[personalt]

I am thinking of doing a rule if attic temperture is more then 15 degrees higher then outside temperture run attic fan..

Questions
1.does elk support any temperture sensor cheaper then $60 elk one? I was wondering if elk sensor was just a resister or is it a resister plus a elk specific communications module
2.most likely I will use cqc for rules since I can get outside temperture from weather channel driver but if I were to get two elk sensors could I do a rule totally inside elk based on the temperture difference between the two values.

 

[apostolakisl]

There is a unit that people have discussed on this board that is about $30 on amazon. It is a networkable item as well as having its own programmable outputs that could be hard wired to the elk. Anyway, it allows multiple (I think 5) temp and humidity sensors to be wired to it (the cheap kind). I can't recall its name but I saw some postings about it just a couple weeks ago.

 

[Lagerhead]

The M1KAM allows attachment of one 1-Wire temperature sensor. But this is not usually more economical than the M1ZTS. Since you are running a computer anyway, you might look to do the whole job with just some simple 1-Wire sensors and a 1-Wire-to-PC adapter.