Yeah, moisture sensors come with their own set of issues, for me primarily cost but there's also the logistics of running all the wires, or do you make them wireless? batteries? where to install them? several per zone to get an average?
The appeal of the camera is that it's cheap and you can use only one or two (front/back) and it "senses" the whole lawn. The problem with the long delayed control response is that once your lawn turns brown it's pretty much already too late, and the system would have a pretty hard time responding to varying conditions such as rainfall one day, or a scorcher week. Moisture sensors would of course have a much better response, but after a lot of work. I think you *may* be able to get a pretty good baseline however with the camera on how long to water each zone relative to the others, and if you correlate with more sensors - temperature and humidity - maybe one could come up with a pretty good algorithm to map those to a control output and use greeness to tune that mapping. Just some ideas I'm tossing around. :v <quote name="plug.mailing-list" date="Sat, 26 Jul 2014 at 09:13 -0600"> > If you use moisture sensors, then you won't need to water the lawn on a time > based schedule. The sprinklers will simply turn on when the moisture content > drops below a certain threshold in that particular zone. > > ----- Original Message ----- > From: "Charles Curley" <[email protected]> > To: [email protected] > Sent: Saturday, July 26, 2014 9:01:14 AM > Subject: Re: Arduino projects > > On Sat, 26 Jul 2014 00:08:35 -0600 > Von Fugal <[email protected]> wrote: > > > * Sprinkler control - "gee it sure is hot today, better give the lawn > > a little extra water tonight", don't have to wait till the optimal > > time or until I get home, by which time I'll probably have forgotten > > about it. ;) > > I've been toying with the idea of having a camera on the lawn to > > measure the "greenness" of the different zones for a feedback > > control, though I fear the response time may be WAAAY too long to be > > useful. :/ > > Let me know when you have that sprinkler control system running. With > all the travel I do, I could use that. > > I think you are right about the response time on the camera, but look > at moisture sensors. Water the lawn at, say, 03:00, see if it is still > moist during the course of the day, and vary the water time accordingly. > Don't forget to offset for trees and bushes adjacent to the zone. > Moisture sensors will also help offset rain. > > -- > > The right of the people to be secure in their persons, houses, papers, > and effects, against unreasonable searches and seizures, shall not be > violated, and no Warrants shall issue, but upon probable cause, > supported by Oath or affirmation, and particularly describing the > place to be searched, and the persons or things to be seized. > -- U.S. Const. Amendment IV > > Key fingerprint = CE5C 6645 A45A 64E4 94C0 809C FFF6 4C48 4ECD DFDB > > /* > PLUG: http://plug.org, #utah on irc.freenode.net > Unsubscribe: http://plug.org/mailman/options/plug > Don't fear the penguin. > */ > > /* > PLUG: http://plug.org, #utah on irc.freenode.net > Unsubscribe: http://plug.org/mailman/options/plug > Don't fear the penguin. > */ > -- You keep up the good fight just as long as you feel you need to. -- Ken Danagger
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