Thermostat user interface

A thermostat, comprising:

• a frustum-shaped shell body having a circular cross-section and a central axis generally perpendicular to a wall when the thermostat is wall-mounted, the frustum-shaped shell body comprising a sidewall that extends along a length of the central axis between first and second ends of the frustum-shaped shell body, the first end of the frustum-shaped shell body being wall-facing when the thermostat is wall-mounted, the second end of the frustum-shaped shell body being user-facing when the thermostat is wall-mounted, the sidewall comprising inside and outside surfaces, the inside surface defining an interior for housing components of the thermostat;
• a circular rotatable ring mounted proximate the second end of the frustum-shaped shell body, the circular rotatable ring having an axis of rotation generally perpendicular to the wall when the thermostat is wall-mounted, the circular rotatable ring being user rotatable about the axis of rotation, wherein the circular rotatable ring rotatable slides about a frame of the thermostat, the circular rotatable ring having an inwardly extending lip or edge surface that is parallel to the wall when the thermostat is wall mounted, said inwardly extending lip or edge being positioned within a groove of the frame, and wherein a corresponding bearing surface of the frame is greased or otherwise lubricated to smooth and dampen rotational movement of the circular rotatable ring;
• a circular cover mounted proximate the second end of the frustum-shaped shell body, the circular cover having a central axis generally perpendicular to the wall when the thermostat is wall-mounted, the circular cover comprising a clear circular center portion surrounded by a colored outer portion;
• at least one temperature sensor for use in sensing an ambient air temperature;
• a plurality of HVAC (heating, ventilation, and air conditioning) wire terminals configured to receive a plurality of HVAC wires;
• a dot-matrix color display element mounted at a location between the second end of the frustum-shaped shell body and the circular cover, the dot-matrix color display element and the circular cover not rotating when the circular rotatable ring is rotated and the thermostat is wall-mounted;
• and
• a processing system provided in operative communication with the plurality of HVAC wire terminals, the circular rotatable ring, the dot-matrix color display element, and the at least one temperature sensor, the processing system configured to:
• cause the dot-matrix color display element to display a numerical value representative of a temperature value;
• determine a user-selected temperature value based on user rotation of the circular rotatable ring;
• and
• send a control signal to the HVAC system via at least one of the HVAC wire terminals based at least in part on a comparison of a user-selected temperature value and the sensed ambient temperature;
• wherein said outside surface of said frustum-shaped shell body sidewall has a metallic appearing finish and wherein said sidewall increases in diameter along the central axis from the first end of the frustum-shaped shell body to the second end of the frustum-shaped shell body such that an acute angle is formed exterior to the thermostat between the outside surface of the sidewall and the wall when the thermostat is wall-mounted, whereby a naturally blending visual appearance of the thermostat with the wall is promoted by virtue of the frustum-shaped shell body, the metallic-appearing finish, and the acute angle when the thermostat is mounted to the wall;
• and
• wherein the dot-matrix color display element is non-circular and the clear circular center portion of the circular cover permits a circular portion of the non-circular dot-matrix color display element to be visible through the circular cover, the colored outer portion of the circular cover masking a remaining portion of the non-circular dot-matrix color display element so as to create a circular graphical user interface.