ccitro / drey Goto Github PK

Background

When trying to pick what temperature to set the thermostat to, Drey looks at the temperature difference between the thermostat's sensor, and the most demanding room's sensor. That difference is a decimal number, but Nest only allows setting temperatures with integer precision.

Problem

Currently Drey uses standard rounding rules to pick a temperature to set the thermostat to. However this often means that the HVAC will stop while the most demanding room is still about 1/2 a degree off of the target temperature.

Fix

Instead of rounding, use either floor or ceiling depending on if the system is in heating or cooling mode. This may cause the system to overshoot the temperature, but at least the target temperature is met.

Currently, the thermostat temperature is read from the thermostat entity attributes. This is rounded to integer precision, but the actual sensor entity for the thermostat has 1 decimal point precision.

When calculating the desired thermostat setting, the difference from the "demanding sensor" temperature, and the thermostat's temperature is required. For the best calculation, the thermostat temperature with the highest precision should be used.