<html><head></head><body><div style="color:#000; background-color:#fff; font-family:lucida console, sans-serif;font-size:13px"><div id="yui_3_16_0_ym19_1_1488861894801_5913" class="qtdSeparateBR"><div id="yui_3_16_0_ym19_1_1488861894801_5941" dir="ltr">Since OpenSprinkler is open source, you could, in theory modify the software so the green house gets watered on a fixed schedule independent of rain.</div><div id="yui_3_16_0_ym19_1_1488861894801_5982" dir="ltr"><br></div><div id="yui_3_16_0_ym19_1_1488861894801_6075" dir="ltr">In my experience, projects like that get put on the round-to-it-list. On the other hand, if I have such a problem with a closed source project, I tend to get annoyed until I find a F.O.S.S. that I can use. Then my blood pressure relaxes and I add another item on the list of projects I might get to someday...<br></div><br></div><div style="display: block;" id="yui_3_16_0_ym19_1_1488861894801_5906" class="yahoo_quoted"> <div id="yui_3_16_0_ym19_1_1488861894801_5905" style="font-family: lucida console, sans-serif; font-size: 13px;"> <div id="yui_3_16_0_ym19_1_1488861894801_5904" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yui_3_16_0_ym19_1_1488861894801_5903" dir="ltr"> <font id="yui_3_16_0_ym19_1_1488861894801_5907" face="Arial" size="2"> <hr size="1"> <b><span style="font-weight:bold;">From:</span></b> Rick Moen <rick@linuxmafia.com><br> <b><span style="font-weight: bold;">To:</span></b> conspire@linuxmafia.com <br> <b><span style="font-weight: bold;">Sent:</span></b> Monday, March 6, 2017 6:53 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> [conspire] Watering automation: an edge case cautionary tale<br> </font> </div> <div id="yui_3_16_0_ym19_1_1488861894801_5910" class="y_msg_container"><br>I think it was around 2014 that the state started talking about<br>requiring residents to hit 'water budget' targets, and hard enforcement<br>started in June 2015. Each household was required to reduce water each<br>month going forward by 32% compared to amounts they used in calendar<br>year 2013 (the 'base year') subject to a floor allocation of at least 6<br>CCF (centum cubic feet; 1 CCF = 748 gal). Starting Aug. 2016 with the <br>easing of the drought, these were changed to 'conservation targets',<br>though budgeting will return if trends reverse.<br><br>I was pretty worried when this happened, because I have 1/3 acre with<br>many fruit trees and plants. Worse, over the 9 years since we moved<br>here, I'd not yet set up a real watering system. Instead, there was a<br>crazy-quilt of soaker hoses and no automation. Soaker hoses are better<br>than nothing, but just barely: They apply water in the same Zip Code as<br>the trees and plants. And, of course, if you forget to turn off the<br>faucet and let it run overnight, oops.<br><br>June, July, and August 2015, we exceeded assigned water budgets -- <br>but I was frantically yanking soaker hoses (anyone need some?) and<br>installing a drip irrigation system. And then, I'm guessing it must<br>have been right at the beginning of 2016, I also completed the primary<br>system by installing solenoid-driven water switches so that the watering<br>could be run by an automated timer. Even though I had a perfectly<br>adequate 'dumb' Rainbird controller, I replaced it with OpenSprinkler<br>(<a href="https://opensprinkler.com/" target="_blank">https://opensprinkler.com/</a>), an Arduino-based replacement. (They also<br>have a very cool Raspberry Pi version.) OpenSprinkler keeps track of<br>the weather and changes watering times accordingly, and can do other<br>nice tricks, and can be programmed & monitored from its built-in Web<br>server. From Jan. 2016 on, water usage has gone _way_ down, especially<br>during our long Mediterranean summer.[1]<br><br>This past summer, I also connected in a water sensor, a gadget you mount<br>on the side of the roof to send the controller a signal if it's rained<br>recently (so it can decide not to water for a few days).<br><br>Result: This winter, our water usage has fallen down to just above zero.<br>The February bill reflected a meter read of 1 CCF, and the March bill<br>that just posted showed a meter read of _0 CCF_. We continue to be way<br>under usage targets, but the last two months are our lowest usage ever.<br><br>Yay, automation. Yay, water sensors.<br><br><br>Automation's your friend, right? In computing, it's practically a<br>mantra: Script anything you can. Automate everything you can.<br><br>And water automation has been a lifesaver around here, let me tell you<br>-- but let me tell you about a weird edge case:<br><br><br>One of the most recent places I extended drip irrigation to is to plants<br>overwintered inside my about 12' x 8' kit-built greenhouse. A couple <br>of large lemongrass plants (native to the tropics) spend winters there, <br>and this winter some hot pepper plants are surviving there, too. All<br>roof and side vents and the greenhouse door are closed up tight, to<br>protect the plants against frosty nights.<br><br>But there's a hidden problem -- that arrived when I added the water<br>sensor. Can you spot it?<br><br><br>Before I added the water sensor, my OpenSprinkler controller would open<br>the solenoids to feed water to the greenhouse (among other places) twice<br>a day like clockwork. Perfect. Exactly what the frost-sensitive plants<br>in there need.<br><br>But imagine during a wet winter like the present one, a two or three<br>week period of rain almost every day. Then, the sensor would suppress<br>all watering -- which is fine for plants outside the greenhouse that<br>would get their share of the rain, but would be nicely automated death <br>for plant inside the tightly sealed greenhouse.<br><br><br>Automation's great -- except where it does clockwork automated failure.<br><br><br>(I'm about to go outside and water the plants in the greenhouse,<br>manually.)<br><br><br><br>[1] Historical household usage in CCF billed:<br> 2014 2015 2016<br>Apr 3 10 2 <br>May 6 7 2<br>Jun 16 15 5<br>Jul 18 15 6<br>Aug 24 13 7<br>Sep 9 5 7<br>Oct 13 7 6<br><br><br>_______________________________________________<br>conspire mailing list<br><a ymailto="mailto:conspire@linuxmafia.com" href="mailto:conspire@linuxmafia.com">conspire@linuxmafia.com</a><br><a href="http://linuxmafia.com/mailman/listinfo/conspire" target="_blank">http://linuxmafia.com/mailman/listinfo/conspire</a><br><br><br></div> </div> </div> </div></div></body></html>