Garden and shrub watering system
My wife has been steadily expanding her garden, shrubs, and other areas in our large yard, and, since we live in a very dry area, these plants have to be watered regularly during the summer months. Unfortunately, we spend much of our summer in the mountains making it difficult to do the necessary watering.. We have used small timers that connect to the faucet but this setup did not do very well last summer. We need something better without spending a ton of money in an underground watering system. In addition, she has defined at least eight zones of watering and will probably grow this number. Orbit and other companies offer a wide variety of watering systems But all are designed to do specific things..
There were several concerns that needed to be addressed before such a project makes sense.
Reliability: This includes the valve hardware and a solid electronics controller that will operate flawlessly over time.
Cost: Not interested in spending a large amount on this project
Labor: Have to be able to do all the work myself
Flexibility: The system must be able to grow in size and complexity without having to redo the system.
This seemed to be a another perfect application for a PICAXE controller. Basically, all the advertised systems are multi-zone timers. With a wide variety of neat things that could be done like, changing the during of water cycles based on rain, high temperature, wind, etc. I have designed several projects using the PICAXE (driveway monitor/light controller, furnace monitor, alarm system) using a variety of PICAXEs (18x, 28x, 40x) and have had rock solid results even with I/O lines running many feet inside and outside the house. Flexible programming with the PICAXE allows me to develop a wide variety of options that would not be available otherwise and add more as needed.
The valves used are low cost Orbit Automatic In Line Jar Top Valve. Lowes had a clearance on the sleeve mount units for about $8. These are the units I used for eight zones. Turns out, I should have used the slightly more expensive threaded type-the learning curve of properly gluing the sleeve units into a PVC manifold was painful-lost three!
I decided on the PICAXE 28-x2 for the I/O flexiblility. Also, I plan to link all my projects together using I2C, once I have a clear understanding on how I2C works in the PICAXE environment. I built three manifolds for our current watering needs. One is the main valve that connects to the faucet and a valve for a physically close garden of roses. The main manifold has four valves and an additional manifold that has two valves and can be expanded.
The controller is be located in my office/shop so I can change the programming as needs change. I have incorporated a secondary manual switch controller located by the faucet so the system can be manually controlled. I attempted to installed LEDs on each valve so I could see activity but decided against this due to long-term effects to the valve. The code can be found here.
I decided to use grey RJ45 cable (outside) of the valve wiring. This may not be a great long term solution but that is what I went with.
As a start, I wrote the program to cycle the eight zones in a two day cycle. Four zones on one day, four on the second day and repeat. I split the cycle to allow watering to occur during the morning hours. The problem, of course, is that I do not have a real time clock. I may use the Net Server as a clock source but am not there yet.. So, using a solar cell to determine whether it is night/day allows the program to determine that there is a new day for watering. I had installed it on the box but added an additional cell looking out the window to catch the first light of morning. This should work well.
Now I just need to wait until the cold mornings rise above freezing to try this project out. I will update when this happens!
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