OpenSprinkler Forums Hardware Questions water flow sensor and valve current sense Re: Re: water flow sensor and valve current sense



Hi Ray, the concern about signal integrity is the rise time of 4ns that may ring quite a bit. Adjusting the frequency won’t help with the rise time or impedance mismatch, but if you haven’t observed any problems I may buy one and put a scope probe on it to see if my simulations match reality.

Thank you for the info on the relay, sounds great. As for current sensing – if we know the water flow rate is reasonable then the valve must be working. Flow rate is most important because I have a lot of area to cover and a busted pipe somewhere is important to fix quickly. I plan on having it check a certain flow rate for each valve and if it’s outside that range too low it would notify me, if too high it would notify and skip to the next valve.

I’ve observed the flow sensor connected to my cyberrain system and essentially when you turn on the valve you get a lot of water flowing until the line is full, and then it stabilizes once all the sprinklers have the air out. This could take up to 2 minutes in my case when you are dealing with longer /large pipes. So usually you can set how long it waits before it samples the flow rate.

Also the flow sensor is helpful when all the valves are off to let you know if you have a leak somewhere before the valves. I had a problem with one hose bib/faucet opening up full blast all night and it would have been nice for something to text/email me an alert if the water was on for more than a certain number of minutes while the valves are off.

For water conservation right now I’m exporting the reports from cyberrain and running a perl script to calculate how much water each zone uses and how much it costs per month, along with any deviation on flow rate compared to last month (in case a leak is starting to occur). I hope to integrate some of these features into your opensprinkler so it’s more automated and share if someone else is also interested.

Sorry for the long post – one more thing. Not sure if you considered perhaps having a second opensprinkler on the network that is a secondary along with a primary controller. So for example in my case I have two controller locations. It would be nice if one location was the primary with 32 valves, and the secondary location was another 32 valves. Then the secondary location could just take commands from the primary one in terms of open valve X etc. while the primary controller could run all the schedules and ‘control’ more than 32 valves. I suppose alternatively you could just run both opensprinklers separately instead of communicating together but this would allow a single schedule so you don’t have to worry about the two controllers watering at the same time and messing up the flow sensor readings etc (if they use the same flow sensor which mine do). Maybe not a lot of people wanting more than 32 zones or more controllers though…

Thanks for the reply and also for such a cool product. Looking forward to it!