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Alan, I’m running OSPi 2.1.9 it only works for me on Chrome and Microsoft’s new Chromium. You may need to delete all your cookies also in the browser to get it to come up.
Well here this is AGAIN since it vanished from the blog after making 1 edit on a typo:
I have been working on this myself and let me explain my approach. First of all the idea of tying a soil sensor directly into OS is, in my view, a waste of time. The reason is that there’s a lot of processing and logic that is needed, too much to load down on OS. So here is my approach:
1) Setup OpenSprinkler (either buy an outright Open Sprinkler controller or build one based on a Raspberry Pi (the second thing is what I did mainly because I wanted an excuse to learn about Raspberry Pi’s but trust me unless your time is worth nothing, it’s way cheaper to buy the entire OS unit ready to roll)
2) Setup a Vera Home Controller.
3) Install The Open Sprinkler app from here (https://github.com/dbochicchio/vera/tree/master/OpenSprinkler) He should have it updated in the Vera Store by now but if not you can install it manually
4) Build a waterproof soil probe such as detailed in the Instructible referenced above a few posts ago. The one in the instructible is unsuitable because it’s not waterproof and it’s not powered remotely but the idea behind it is good.
5) Write a Vera app that communicates with the soil sensor
6) Build and install a weather station around an arduino or raspberry pi
7) Tie this into the Vera
8) Write a scene in the Vera that manages sprinkling using the soil moisture and weather conditions. This is a lot more complex than it looks because of a number of rules:
a) you don’t want to water on days with low humidity because a lot of the water evaporates before going into the soil
b) you want to have a day or so where the sun thoroughly dries out the plants and surface of the soil or your are going to promote moss & mold and mildew growth as well as rot the plants
c) you don’t need to water as much when it’s cloudy because the decreased solar radiation means the plants activity is a lot lower and they are not taking up as much water
d) Soil water level only tells you the moisture where the probe is not the entire lawn so if you wanted to go off soil moisture you would need a bunch of probes
e) you don’t want to water when the weather forecast says it’s going to rain tomorrowProfessional agricultural like golf courses and farmers use cameras pointed at the plants, weather data, and seat-of-the-pants, thumbs-behind-the-britches experience to control watering and they are constantly tinkering with it. But they are running thousands of gallons of water and have labor costs for moving the sprinklers, and electricity costs for pumping water that make a mistake very costly. Lawn care companies that program sprinklers for homeowners simply over-water because the homeowner isn’t going to scream at them if their water bill is high but they will scream at them if the lawn is brown. DIY gardeners use the “stick finger in dirt and look at it to see if it need water” method which is the most accurate way of doing things – as long as they do it every single day – which 90% of them don’t.
The goal of a watering system is to approximate the “look at it and stick finger in dirt” method as close as possible with software and the end goal being to use only the amount of water the plants need to have and no more. Unfortunately that is a lot more complicated than just attaching a soil sensor to the sprinkler and sitting back and letting it do it’s thing.
I’m basically at step#4 right now. Unfortunately I have a ton of other stuff on my plate right now so I likely won’t be able to get on it for some time. I started this 3 years ago with a remote lawn 90 miles away, and Rainbird sprinkler controller at the lawn and nothing else, so it has taken a lot of time and work to be able to get to step #4. But at this point I can see the lawn (remotely) turn on and off the sprinklers and set a sprinkling schedule, so at least I am no longer operating blind.
Well I’m going to bump this from last year with an “I told you so” to the question of “I’ll be sure to come back here if I need any help listing all the reasons something can’t be done that has already been done” and reiterate what I said in my original post:
Reverse engineer the most popular 2 wire commercial sprinkler system on the market and produce a compatible controller that works with all their valves, and that way the greenskeeper can buy all -their- valves and the cheapo controller.
Go ahead and try it. A couple things you might go back to Ray’s page and look at again:
1) Inrush current. Ray mentions this on the page. The solenoid needs a spike of high current to get the slug of iron in the solenoid moving. For a very long run of wire at 18ga it’s not going to be reliable because for the few microseconds that it’s pulling 20A or more the voltage is going to be way too low. Which is why I said I’m pretty sure the commercial systems are using a boost/buck system.
2) Regular cat-5 ethernet is 24ga not 18. Also, the jacket of regular ethernet will not remain intact in water. I’ve seen enough of it pulled out of pipes that had water in them to know what happens to regular PVC ethernet cable jackets. They make underground rated ethernet and it has the same tough PVC case that the 18ga sprinkler wire has. I think you will find underground rated ethernet to be the same cost as sprinkler wire. You are also ignoring that the largest cost in ANY sort of large distributed network is laying the wire. NOBODY in charge of a large system is going to put in an untested system that specs DIFFERENT cabling than all the other existing competitive 2 wire sprinkler systems on the market.
3) The reason sprinkler systems don’t use motorized ball valves is so that if power is lost the sprinkler valve shuts off. Otherwise you have your sprinkler going and there’s a power failure or the controller craps out and then the sprinkler is running all night long and you just lost $200 worth of water and caused a flood. Of course that then means that the valve has to be held open by continuous current. And if you have 5-6 valves actuated at the same time you run out of current carrying capacity on the wire.
4) Sprinkler system plumbing is organized as follows, valves are generally star topology to the water source, zones are daisy chain from the valve. In small home systems the valves are usually placed next to the water source. In large systems the valves are out in the field. Think about what happens to a daisy chain system that is mapped over a star topology – for every valve you are going to be running TWO pairs to it – one from the hub out to the valve and one from the valve back to the hub then out again to the next valve. This is because they are only going to dig 1 trench for the water pipe and the cable for the valve it’s a lot cheaper. That’s why the cable length in theses systems is so long.
You did mention the issue of powering the controller at each valve so I’ll give you that.
You are also ignoring the inherent flaw in a daisy chain config which I mentioned already which is if there’s a break in the system then all the valves after that are dead. If you had any experience in this sort of thing you would have known that this could be solved by creating the daisy chain in a loop with both ends of the loop terminating at the sprinkler controller.
If I was running a golf course for me to send a tech out to replace a failed valve in a sprinkler is 2-3 hours of labor which dwarfs the piddly amount of money I might save on a cheaper node. If I buy your cheaper nodes and they have a higher failure rate my savings will be eaten up.
I am sure that if you were to keep at this after a string of failed hardware behind you and a pile of wire pulled out from underground and a long enough time you would be able to create a running system. But in half the time a lesser schooled guy could have probably reverse engineered the most popular 2 wire commercial sprinkler system on the market and produced a compatible controller that works with all their valves, and that way the greenskeeper can buy all -their- valves and the cheapo controller and been watering his lawn by the time you get something working.
If you absolutely must design your own then why not use the cheapest wire possible – 28ga telephone wire – and run a high frequency on it like 600 Hz AC at 200volts and then you can use tiny toroid core transformers at each valve to drop it down to 20v AC, and it’s also easy to rectify that and get as much current you want to power a controller and a valve. And you can make frequency shifts to carry data to the controller. That system probably will carry the signal a few miles….
There are many 2 wire systems out there. Not for sprinklers. The problem is energy. You cannot shove enough power over a very very very long 24ga wire to actuate a solenoid even at 24v. The people who want 2 wire want to daisy chain them from valve to valve which also means if anywhere the wire is cut it takes all the solenoids after that out of production.
You want to do 2 wire then use 14 or 12ga romes and bury it. You wanna spend $200 on 200 feet of “sprinkler wire” then?
The only way to get around this is raise the voltage. But above 24v requires a licensed electrician to install.
The commercial systems have the same problem. I am sure they use remote power or power extenders (step up step down transformers) to solve this. They probably per code require licensed electricians to install.
I just bought an opensprinkler pi. I have a pi 3 sitting around that I got free. I’m looking forward to setting all this up this weekend.
Just a FYI it seems as though TIAO is “currently working on the next generation of the TIAO smart sprinkler controller” from here:
https://www.diygadget.com/tiao-smart-sprinkler-pi-16-station-sprinkler-controller-open-source-desktop-mobile-appSo they must be still selling the clones enough to make it worth while to put development time into it.
I bought the O.S. hardware because O.S. is running the cloud servers and it’s a way of kicking some money to support that, even though I will mostly not be using the cloud server (since I have a permanent VPN to the remote site the sprinklers are at)
