On 07/26/2014 09:01 AM, Charles Curley wrote: > 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.
One can fairly easily make a simple moisture sensor with two wires and measure resistance. Of course the electrodes break down over time. And also the reading depends on soil type, water composition, etc. Another good sensor that I've been meaning to buy and test out (not too cheap; it's $40) is the Vegitronix VH400 sensor[1]. The site is confusing because it talks of a VG400 and a VH400, but somewhere it says one of them is discontinued and to buy the other. Anyway, the only problem with this is trying to make sense of the data. That will take some trial and error. [1] http://www.vegetronix.com/Products/VG400/ /* PLUG: http://plug.org, #utah on irc.freenode.net Unsubscribe: http://plug.org/mailman/options/plug Don't fear the penguin. */
