Thermostat user interface

A user-friendly programmable thermostat is described that includes a body having a central electronic display surrounded by a ring that can be rotated and pressed inwardly to provide user input in a simple and elegant fashion. The current temperature and setpoint temperature are graphically displayed as prominent tick marks over a range of background tick marks on the electronic display. Different colors can be displayed to indicate currently active HVAC functions, and different intensities of colors can be displayed to indicate an amount of heating or cooling required to reach a target temperature. The setpoint temperature for the device can be altered by user rotation of the rotatable ring, and the programmed schedule can be displayed to the user and altered by the user by virtue of rotations and inward pressings of the ring. Initial device set up and installation, the viewing of device operation, the editing of various settings, and the viewing of historical energy usage information are made simple and elegant by virtue of the described form factor, display modalities, and user input modalities of the device.