Smart Lawn Irrigation

smart irrigation

A decade ago I had an in-ground sprinkler system installed. When I had it installed I asked the installer to just leave the control wires for the zones un-terminated. I would be adding my own smart irrigation controller. At the time the installer though I was crazy and he was missing out on trying to sell me some over priced dated timer. He said “you can’t have a system without a clock”. That is precisely what I wanted to avoid. Just a simple “clock”. I wanted smarter irrigation that would adapt to rainfall, wind, and temperatures swings.

Note: If you are installing a sprinkler system in cold weather climates the next racket to look out for is winterization. The installer can install drain valves at the low ends of the system at each zone but none of the installers do. They will tell you that they don’t work. That way the installer can try to get you to pay them to blow out (winterize) your lines each year as a means of recurring income. You can either install the self draining valves at low points or buy your own adapter to blow out your own system.

Evapotransipiration + Internet

Evapotranspiration is the process by which water is transferred from the land to the atmosphere by evaporation from the soil and other surfaces and by transpiration from plants.

Evapotranspiration and smart irrigation

The idea is that by knowing your precise location and factoring in internet and local weather sensors as well as historical irrigation events a system could be smart enough to automatically adapt the water schedule to only water when it should and how much it should. This is a dramatic departure from the legacy “clock” method of the past decade where a timer just turns a system on/off based on a schedule, raining or not, windy or not, necessary or not.

Most of the modern irrigation systems have caught up to this concept but most of the are also trying to get customers to pay monthly for what you can get free with a single installation.

One time purchase – Set it and forget it

I started using evapotranspiration based controllers a decade ago with the EtherRain8. This was a very simple web based product but it was perfect at the time for what I was attempting to do. Essentially, each year I just turn on main water valve (I winterize it each winter) and then walk away. The unit knows what it needs to be doing. The old EtherRain8 was decent for the day. It had a simple web based interface and the manufacturer would even give the code to the website free to users as open source. I really liked his business model.

RainMachine Smart Irrigation Controller

As technology evolved so did the aftermarket irrigation controllers. I eventually migrated to the RainMachine Touch HD-12 smart irrigation controller. I really like this controller. It is built on android so it has a very modern looking interface and a great android app. Oh, the most important part. No reoccurring fees. You don’t have to pay for the app, you don’t pay for a service. You just pay for the device as a one time investment and you are automated! It is hard to find suppliers that aren’t trying to hit you with cloud based monthly fees so I try to support the few left that do not.

RainMachine HD-12 Smart Irrigation Controller
  • SMART SCHEDULE & SAVE WATER – Save water with real-time weather adjustments. (EPA WaterSense Certified, check for rebates)
  • CLOUD INDEPENDENT – All personal data stored locally
  • Continues to work even when WiFi is down
  • Forecast spatial resolution: up to 1.5 km
  • FREE WEATHER DATA – Direct access to NOAA, METNO or Wunderground, OpenWeatherMap, NetAtmo. Use National or Personal Weather Stations for pinpoint accuracy
  • CONTROL FROM ANYWHERE – Color Touch Screen, iPhone, and Android, PC browser access with dashboard stats. Works from Home, Work or Vacation
  • UPDATED MODEL (2019) – Improved WIFI. hundreds of Schedule and UI improvements. Integrate with Alexa, Google Home, Nest, WINK, SmartThings via IFTTT.

I actually use the Alexa integration quite a bit. As an example, when the kids want to go run around in the sprinkler you can use the command, “Alexa, turn on zone 6 for 30 minutes”. Boom!

Getting Started

Wiring is pretty simple and the instructions walk you through everything. Essentially you label the wires that are connected to your current controller. Loosen some set screws to remove the wires. Connect the wires to your new controller, complete the guided setup, and your are up and running.

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