Anthony’s Smart Sprinkler Timer idea
The general idea came from the observation that people have more and more electronic devices around their houses that they don’t know how to use. A while back I heard that most Americans do not even know how to program their VCRs. I’m sure even fewer can properly operate their sprinkler timers. Clearly, the right answer to all human interface issues is the browser. Almost everyone knows how to use a browser and interact with web pages. The best thing about most web pages is that you don’t have to memorize how to do things. It’s all there on the screen or just a click away.
Back to watering the lawn; I also noticed that the City of Irvine, as well as many places around the world, are running a bit short on water. The Irvine Ranch Water District is constantly promoting smart water usage. Water conservation is becoming ever more important as the planet heats up and as energy costs go up. For households with yards, the water consumed by the sprinklers is quite significant. In many cases, half the household’s water bill goes to the plants in the garden. Unfortunately, people do not know how to use their timers, and therefore just leave them alone. Many people open the manual when they first buy the timer, adjust the settings and leave it. Even if they do know how to program it, all timers ask the same two questions ; “When should it water” and “How long should it water”. Furthermore, if they know the answer on one day, the amount of water plants need varies day to day. The amount of daily water should change with the weather.
Putting these two observations together, I came up with the perfect sprinkler timer. It should have no knobs or display to confuse people, just a green LED that says the network connection (WiFi or wired) is up and running. A server, somewhere on the Internet, checks the weather prediction for each local area and sends a new schedule to the hardware each day. The user interacts with the server via an ad supported web page. The ads on the webpage are targeted to homeowners with yards and gardens. At setup time, the user answers simple questions about the types of plants and sprinklers they have, and the server calculates the rest. If there is ever a problem, the server can email or notify the user before the plants die. The best thing of all is that it will stop watering days before a rain and water like crazy before a Santa Ana wind condition. Plants will thrive while saving lots of water.
Currently, for millions of Americans, the algorithm they use to water their plants is:
Step 1) Install timer and randomly pick settings.
Step 2) Forget about it.
Step 3) Notice plants are dying due to the extreme heat.
Step 4) Turn up the amount of water on all lines.
Step 5) Goto step 2 unless you are the one paying the water bill
Step 6) See your water bill is too high, turn down the water on all lines.
Step 7) Goto step 2.
This is a terrible algorithm. If professional farmers used this algorithm, we would all starve to death. If there is one thing humankind knows, it’s how to water crops. Irrigation is a science that is taught in all agricultural universities. Farmers work so close to the line, so that even a loss in yield of a few percent can cause big problems. They can’t afford to have their crops show signs of water stress. They also can’t afford to over water. The algorithm for lush, thriving plants while saving the maximum amount of water is well known to the farming communities. My idea is to bring that knowledge, plus real-time weather data, to the yards of America. I figure a bedroom neighborhood like Mission Viejo could save 25% of their current annual water usage with a timer like this.
One of the best parts of this idea is that the hardware is very cheap to build. The most expensive part of little electronic devices is the human interface. This timer has none. The main embedded processor is now selling for $1 (in bulk). I believe a 16-line device could be built for $20, sold for $40 and the ads generate most of the profit. There might even be enough profit in the ads that the timer could be given away at cost or even free.
The details are too much for this web page, but they include the calculation that estimates the amount of remaining water in the plants, “in-soil and moisture module”, the web based GUI and the optional peripherals. In general, the whole thing is a win-win-win solution. The homeowner wins because their plants do better while saving on their water bills. The company wins because of profit on each unit and ads. And the community wins because they can spend less on water infrastructure and pumping costs.