Before we started landscaping I had grand plans for irrigation for our house. It was borne out of two desires.
1. With a growing busy family I can’t guarantee that our plants and lawn can be watered
2. Because I can
What quickly became apparent on my home automation journey is that the more sensors I had connected to my Homevision Pro the more powerful my decision logic could be. It was for that reason alone I didn’t want another system separate to the Homevision Pro calling the shots.
I looked at using the Homevision Pro but didn’t really want to waste valuable output ports and upon reading a website I regular read I elected to use a product, . OpenSprinkler. What drew me to OpenSprinkler was that it was an irrigation controller that was TCP/IP enabled and after more investigation I figured I could make simple HTTP GET’s to control the system. Opensprinkler is a great product but it is also quite basic in its logic. It can water based on timers and a rain sensor. But it cant water based on more advanced weather conditions.
– If today is going to be 40C do we need to alter how much water is being dispersed and at what time
– If it rained 7mm of rain over night but isn’t raining when the cycle is set to start do I really need to water?
So whilst I am a big advocate of OpenSprinkler I decided to just use it as a ‘dumb’ TCP/IP irrigation controller and let Homevision Pro call all the shots.
Bill of Materials
– 1 x OpenSprinker ($180AUD)
– 1 x 24V AC PSU ($30AUD)
Total Cost = $210AUD
– Soldering Iron
– Screw Driver
Step 1: Mount and Connect to Network / Valves
Being a small unit I elected to mount OpenSprinkler inside my Homevision Pro enclosure. There was just enough space inside this enclosure for a nice neat snug fit. Ethernet, power and valves were all connected to OpenSprinkler. That’s about all there is to do for physical installation. The rest of this is in the logic.
Step 2: Figure out how OpenSprinkler works
OpenSprinkler is simple to use. The thing is I want to make calls to it that my browser or smartphone application makes. I used Firebug which an excellent Firefox plugin and this showed the following structure
GET http://OpenSprinkler_IP + Station Name + Status ON / OFF + seconds
which translates to
The above GET will cause station number 1 to turn on for 120 seconds. It is a simple as that.