If the Rachio used wifi/cloud based soil moisture sensors (assuming these exist, etc...and I know this on the list of a future update), would you even need to calculates ET from weather stations or use historical ET values?
Seems like using moisture sensors would really simplify things and make for easier setup. Couldn't the Rachio just get moisture data from moisture sensors, a rain (yes/no) type signal from a rain sensor, and weather forecasts from the local weather station? If you had those 3 things, it seems like the Rachio would become extremely accurate, and easier to setup. What am I missing?
BTW, I'm thinking, if the forecast calls for rain thus skipping irrigation but it doesn't rain, the moisture sensor would show less moisture therefore the Rachio would irrigate the next day knowing it really didn't rain.
Seems like this would be the way to go. I could see a wifi cloud based sensor in each irrigation zone.