I have a quick question about the POE standard: is 48vdc the standard voltage for POE? That’s definitely too high for driving solenoids directly (the DC-powered OpenSprinkler uses a 7.5VDC power supply, though anything between 5VDC to 12VDC is also fine). If 48vdc is standard, that means it needs to be stepped down (through a switching regulator) to something in the 6 to 9V range. If POE can carry 24VAC, that would be more suitable as then it can work with AC-powered OpenSprinkler.