[HH] sprinkler controller

[Tom Metro]

Greg London wrote:
>>   Stafford himself has used his creation to power his home sprinkler
>>   system
> 
> Home Depot sells a programmable hose valve for $40.
> It has an LCD screen and a 4-way button to access the menus.
> You program in the time, when you want to water, how long,
> and how many times a day. and it does the rest.

Sure, and I use one of those off-the-shelf controllers, but that doesn't
mean they aren't lacking.

A more sophisticated controller can:
 -allow you to conveniently remotely adjust the programming;
 -allow you to design a watering pattern that varies through the season,
instead of just X times per week perpetually;
 -accommodate an infinite number of watering zones;
 -provide feedback to a home automation system for when the system is
active (so you know that it is still working and can estimate water
usage, accounting for scheduled periods the controller skipped because
it thought watering wasn't necessary).

Then you'll see some off-the-shelf controllers that have rain gages,
which a home brew controller could replace with weather data supplied
over the Internet, but in my opinion the holy grail of irrigation
feedback mechanisms is a buried moisture sensor. There are a few
off-the-shelf controllers available at the home centers that offer that
as an option, but you get one sensor per controller, and it is typically
an unreliable, low-end sensor. A home brew solution could use multiple
high-quality wireless sensors per zone and average them. It could also
notify you if it sees no change from a sensor or other anomalies.

You can find some of this stuff in $1000+ pro irrigation systems.

So yeah, I can see why someone would be motivated to create their own
controller.

(I don't recall if it was in the video for this article or somewhere
else, but someplace this past week I glanced over a D-I-Y sprinkler
system that used these Orbit valves:
http://www.amazon.com/Orbit-Sunmate-62035-Watering-System/dp/B0016HQOYC/

that are available at most home centers. They're packaged up nicely in a
weather proof housing with hose connectors and a cable terminated in a
1/8" plug. Nice and user friendly, but I think I'd opt for the cheaper
"raw" solenoid valves with pipe fittings. Better yet would be finding
motorized ball valves, which avoid water hammering.)

 -Tom