Automated Irrigation System – Take 2

September, 2012

My first attempt to automating the irrigation system was successful for a while, but one of the valves unexpectedly stopped working which denied my yard water for over a week.  It was time to make a significant investment and have a whole-yard irrigation system professionally installed.  13 zones and 54 sprinkler heads now cover my entire 1 acre yard.  Installation took almost 2 weeks, but they did a great job.

While the crew was hard at work in the yard, I was hard at work updating the Watchdog Irrigation Control module to control the sprinklers.  I selected a Grayhill IO board for controlling the irrigation valves in the yard.  These gave me opto-isolated control to protect the PC from a lightening strike.  I re-wrote the first generation Irrigation Control software to work with an Arduino Mega to control the Grayhill relays.  I continued to use the soil moisture sensor system, but attached 4 additional sensors buried in the back and side yards.  I added a graphical view of the yard to show active irrigation zones and soil moisture status.

In addition I also had a whole-house water meter in-line prior to the new branch that feeds the irrigation system so I can now determine how much water is consumed.  As an added benefit, this meter also helps detect a leak so I can be notified.  After much research, I settled on an AMCO C700 meter which uses a positive displacement technique allowing for precise measurement at low and high flow rates.  It also requires no power source required and an integrated computer interface.  I extended the wire to the Arduino Mega which counts the pulses (1 pulse = 1 gallon).  My contractor used Sharkbite fittings to connect it and perform the other pluming modifications.  It was quick and easy.

Later, I added a HTML5 interface that lets me control the irrigation system from my smart phone or iPad while I’m in the yard.  I used Visual Studio .NET to write the ASP.NET project.  I haven’t done an ASP project in a long time, so was pleasantly surprised by how it has evolved.


426189_527155747311654_10851324_n (1)  This is by far the coolest machine I’ve ever seen. I has a blade on the back that vibrates the dirt out of the way and drags pipe and/or cable underground behind it. They didn’t use the trenching blades on the right.

408721_527156150644947_1829065140_n  Raw materials ready for installation. The white pipes are always under pressure, and the black pipes are more flexible and able to be moved easily.

227955_527156207311608_606400034_n  I had them install a water meter so I could monitor water usage for the whole house. The coiled wire let’s me wire it straight into a sensor. It connects the circuit after a gallon of water has passed. My software counts the gallons and stores them in a database.

76511_527156317311597_280396901_n  The end result – each zone has between 3 and 5 sprinkler heads. They throw water uniformly about 25 feet. Love Rainbird products.  For the most part, not much of the lawn was disturbed. We’re planning to re-seed this fall and things should be looking great next spring!

292989_527156347311594_215450467_n  This is the software I wrote to control the whole system. I built this for a fraction of what it would have cost for them to install a controller. I now have complete remote control of the sprinkler system and safety features. It also runs in automated mode by checking the weather and soil moisture sensors in the ground to determine if it should run a cycle. I added a fun feature that highlights the sprinklers that are active in real-time so I can watch the process remotely as it cycles through all 13 zones.

4740290  Grayhill IO Rack with relays for controlling the irrigation valves.



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