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A Smart Lawn Sprinkler System?
An anonymous reader asks: "I'm about to install a sprinkler system for my lawn. There are lots of timers and computers out there to automate the watering of your lawn. However, before I go out and buy something, I wanted to know if there are any interesting open source projects for watering lawns. I've heard about smart sprinklers that get weather from the internet/satellite and water accordingly. What have other Slashdot readers done?"
If you're looking for solutions to water your gardens, aim to get a system which is economically efficient. Use your common sense as well, don't water your gardens if it looks like it's going to rain and I'm sure the lawn without having to be watered by the sprinkler system everyday.
Also, place them strategically around the lawn so that you are getting the maximum use out of the sprinklers, placing them where the water hits the pavement more than the lawn should be avoided.
The most important thing is, to get something that is efficient and doesn't use up huge amounts of water. In the long run, you'll save money and if you're in an area that is prone to long periods of time without rain, then others will appreciate you for it.
Ask yourself if you really want a lawn. I suspect most people don't but they've never stopped and considered the alternatives. Consider these problems with lawns...
The silliest thing about grass is that it's an artificially stunted plant. The grass wants to grow long but by mowing it you are cropping it to the roots. The grass is permanently kept in the juvenille state. Why bother?
So what did I do? I got rid of my grass. A few mounds of dirt to give the garden a bit of privacy. Woodchip on top to shade the soil and blanket the roots. I put in some native bushes, flowers and trees. Built a nice path through the garden. Then I built a paved area where I can put some chairs and a small table. Now I can sit in my garden and enjoy the beautiful scenery. I don't have to see the neighbour's laundry hanging on their washing line. I also don't have to water it more than once a week because of the woodchip. Native birds, lizards and insects love my garden; it's a healthy thriving ecosystem. Meanwhile my neighbours waste 3 hours of every weekend mowing their ugly lifeless lawns.
"Smart" means getting tried and true equipment designed for the purpose. A good timer will do everything you need reliably and with minimum power draw. Just be sure to get a timer with non-volatile memory and a backup battery for the clock.
Any decent timer will allow you to add a rain sensor that will turn off the sprinklers if it rains. Most rain sensors consist of pieces of material that absorb water and swell up causing them to push a switch. The sprinklers won't resume till the sensor dries out and the amount of moisture needed to stop the sprinklers is adjustable. Butt simple and reliable.
If you want to get way fancy then you can get a system that incorporates soil moisture sensors.
Depending on your situation you may want to check out subsurface drip irrigation for the lawn. Subsurface drip is generally more expensive but really excels 1) in very hot areas, 2) for oddly shaped or narrow areas that don't work well with sprinklers, 3) where it is often windy and 4) on steep slopes.
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"You are not remembered for doing what is expected of you." - Atul Chitnis
"Code has been written for DSC Alarm pannels, Stargate LCD displays, Slinke IR send/receive, Marrick X10, RCI X10 sprinklers, Xantech preamps, ISDN modems, voice modems, ComPool and Aqualink pool equipment"
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http://www.misterhouse.net/
There's several perl sprinkler scripts
Words to men, as air to birds.
I've heard about smart sprinklers that get weather from the internet/satellite and water accordingly. What have other Slashdot readers done?"
When you put in a sprinkler system... you plan it out accordingly so it fits your lawn, where you have trees (and need less water due to shade), where you need more water (gardens), and so on. As well, you can also have a rain gauge put in with the sprinkler system so that it doesn't run after it's rained. The only reason to have a satellite controlled system is to impress your neighbors momentarily before they realize what a dope you are for wasting money on that.
I had tried X-10 years ago and it seemed pretty lame, but I recently installed the latest hardware on my home server and bought a Rain8 and a rain sensor and it works great.
The best part is that the Indigo software for OSX that drives the X10 has an awesome community who have come up with plenty of ways to do what you're asking about.
Mark Gibbs at Network World ran a http://www.nwfusion.com/columnists/2004/071904gear head.html/couple of articles about networking the garden. X-10 came up, as well as some other interesting technical problems. He points to a couple of sources for software, mostly closed source.
And xeriscaping http://www.google.com/search?&q=%22xeriscape%2 2/ may give you a few ideas about designing for a water-restricted future.
Back in the early days of the space program, NASA spent tens of thousands of dollars on research to develop a pen that would write in zero gravity. The Russians used a five cent pencil.
Use a timer. A basic four or six zone timer with battery backup will be far more cost effective and reliable than a computerized and connected solution. I had one of the fancy electronic timers for a while. After having it knocked out by lightning a couple of times (remember, these are connected to low voltage lines running underground across your property) I got a better solution.
I bought an inexpensive 6 zone timer with built in battery backup that I could set up in acordance with local watering restrictions that would handle my needs. It even had the ability to hook in a rain sensor to interrupt the cycle if it had been raining recently. It worked great. (May still be, I sold the house.)
-- "Never underestimate the power of human stupidity." - R.A.H.