You cannot change the default Temp-device without affecting all of the same type (vera has no "override" functionality in their device definition files). So.. what you can do is to create a new device type used by the Arduino plugin. Here is some documentation of the files needed. http://wiki.micasaverde.com/index.php/Luup_plugins:_Static_JSON_file (http://wiki.micasaverde.com/index.php/Category:Development) And this is where you set your own: https://github.com/mysensors/Vera/blob/master/L_Arduino.lua#L55