Hi John, another John here from Vancouver Island, BC, Canada. I live on a rural property serviced by a 150 foot deep brackish well (10% salt water) with low yield. I have been building a water treatment and storage system the last year or so, I’m about half way through the project. Firstly I bought a 12-30 volt DC solar deep well pump for pulling out the well water, and I bought a water pressure transducer ‘custom built’ from somewhere in China – cost me about $100 for the transducer, stuck it down with the pump, and the pump cost was around $300 (Sun Pumps, Texas). The thing only puts out 1-2 gal/min which is well matched to the well capacity. The pump runs off a variable DC power supply which I can vary the voltage programatically (to date I have just been running it at 30 volts). The transducer senses well water level by a 4-20ma current output which can be read easily with an “adc in” on an arduinio, pi, picaxe, etc. The water pumps to a small (200 gal) storage tank, and is re-pumped through a water softener and Reverse Osmosis (2500 Gal/day) unit which fills one of two large storage tanks, driven off regular manual float switches. One tank is domestic use only (1,200 Gal), the other one is irrigation and/or domestic use (2,500 Gal). The second tank can also be filled by a separate rainwater system which runs when the second tank is not full, and there is rainwater in the separate rainwater collection sump. The irrigation tank serves the irrigation system (not yet completed), and toilets in the house (toilets can be temporarily valved back to the domestic system in winter if need be). In a pinch, I can divert the irrigation system over to the domestic system, but would only do this in an emergency, after chlorinating the water first.
I am interested in the open sprinkler system, I have a beaglebone black that I am not using so I could go with that, but I am interested in making the irrigation system fairly smart, so it corrects for soil moisture (potentially separate moisture sensors in each irrigation circuit, or at least in each gardening area), and I will install “hall effect” pulse flow meters and shut off each curuit based on flow delivered, and weather situation that day. I would also like to have code monitor the well water levels, and when they are getting too low, to drop back, or eventually eliminate irrigation all together. So I would be looking for, say, a “percent duty” of some kind that I could send to the OS system (or code it in) so that the sprinklering rates could be adjusted by a percentage that varies by the amount of water supply available at the time.
I think I will send this in as a request for possible code and/or hardware changes in future versions of OS as well.
Hope this helps?