hult
Active Member
Michael M has created a remarkably sophisticated, flexible, and --especially -- field-tested irrigation tool for Home Automation. Glad to help in some small way.
Marc -- hult at hydrologist dot com
ground moisture sensor
- Thread starter apostolakisl
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Michael M has created a remarkably sophisticated, flexible, and --especially -- field-tested irrigation tool for Home Automation. Glad to help in some small way.
Marc -- hult at hydrologist dot com
apostolakisl
Senior Member
Well things have changed around here. We got 12 inches of rain in 48 hours (Hermine). Won't be doing any watering for a while. What kind of name is Hermine anyway? I thought it was something madeup for the Harry Potter books.
I was thinking, what about using IR thermometer to monitor surface temp of the grass and surface temp of some index item. There should be a relationship between those temps that tells you how much water is in the soil. Moist soil should heat and cool slower than dry soil as the air temp and sun cause it to warm and cool. Comparing the temp curves of the index item to the ground might tell you how wet the soil is where dryer soil will behave more like the index item and wetter soil will heat and cool more slowly. Of course the issue of sunless barely changing temperature days may complicate things. But those types of days don't usually call for watering anyway.
I was thinking, what about using IR thermometer to monitor surface temp of the grass and surface temp of some index item. There should be a relationship between those temps that tells you how much water is in the soil. Moist soil should heat and cool slower than dry soil as the air temp and sun cause it to warm and cool. Comparing the temp curves of the index item to the ground might tell you how wet the soil is where dryer soil will behave more like the index item and wetter soil will heat and cool more slowly. Of course the issue of sunless barely changing temperature days may complicate things. But those types of days don't usually call for watering anyway.
ddennerline
Active Member
I have been trying to figure out how to control sprinkler system with ElkM1 and provide some climate based go or no-go capabilities. I purchased a Rain8 Pro2 Master RS-232 and M1-XSP. Now I have been researching if there’s a way to do ET or more advanced irrigation control using only Elk (no PC involved).
Would either the Vegatronix or Irrometer 200SS-V (http://www.irrometer.com/datasheets/405.pdf) work directly with an ElkM1G using zones 1-16 voltage monitoring capabilities. The Irrometer requires a 5v input. I have read comments in Internet postings that Irrometer 200SS has stability problems in that voltage jumps around quite a bit. The Vegatronix would work with standard 12vdc Elk power.
Has anyone tried to hook up one of these sensors to an Elk and write rules? If the sensors produce unstable values, the Elk does not have any statistically filtering capabilities such as calculating exponential moving average. You may be able to get around this by “sampling†the sensor and incrementing a counter each time threshold is exceeded.
The Rain8 Pro2 master comes with a relay jack that can be used for rain or flow sensor. I suspect you could write some Elk rules to create a daily go or no-go program. This program would run as separate routine independent of daily on/off scheduler. The go or no-go subroutine would enable/disable a switch tied into Rain8 sensor jack.
I looked into what it would take to interface a Hunter ET system (http://www.hunterindustries.com/Resources/PDFs/Owners_Manuals/Domestic/lit399w.pdf) without purchasing a Pro-C controller. Apparently, the ET controller interfaces to Pro-C using a serial protocol (http://www.homelogic.com/pdfs/notes/irrigation/hunter.pdf). I suspect Hunter would never release the physical transport specification. The product is not too expensive ($~250).
Would either the Vegatronix or Irrometer 200SS-V (http://www.irrometer.com/datasheets/405.pdf) work directly with an ElkM1G using zones 1-16 voltage monitoring capabilities. The Irrometer requires a 5v input. I have read comments in Internet postings that Irrometer 200SS has stability problems in that voltage jumps around quite a bit. The Vegatronix would work with standard 12vdc Elk power.
Has anyone tried to hook up one of these sensors to an Elk and write rules? If the sensors produce unstable values, the Elk does not have any statistically filtering capabilities such as calculating exponential moving average. You may be able to get around this by “sampling†the sensor and incrementing a counter each time threshold is exceeded.
The Rain8 Pro2 master comes with a relay jack that can be used for rain or flow sensor. I suspect you could write some Elk rules to create a daily go or no-go program. This program would run as separate routine independent of daily on/off scheduler. The go or no-go subroutine would enable/disable a switch tied into Rain8 sensor jack.
I looked into what it would take to interface a Hunter ET system (http://www.hunterindustries.com/Resources/PDFs/Owners_Manuals/Domestic/lit399w.pdf) without purchasing a Pro-C controller. Apparently, the ET controller interfaces to Pro-C using a serial protocol (http://www.homelogic.com/pdfs/notes/irrigation/hunter.pdf). I suspect Hunter would never release the physical transport specification. The product is not too expensive ($~250).
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