Determining rotation using sensor displaced from magnet

Abstract

A device may be configured to control a heating, ventilation, and air conditioning (HVAC) system within a building. The device includes a rotatable dial comprising a first gear; a second gear configured to engage with the first gear, wherein a rotation of the first gear causes the second gear to rotate; a magnet placed on the second gear, wherein the magnet rotates with the second gear; a sensor configured to generate an electrical signal which indicates a rotational position of the magnet, wherein the rotational position of the magnet indicates the rotational position of the second gear; and processing circuitry. The processing circuitry is configured to receive, from the sensor, the electrical signal which indicates the rotational position of the second gear; and change a temperature set point based on a change in the rotational position of the second gear.