Irrigation Flow System

[rgsparber]

PJ,

The one thing I am positive about in all of this is that a patent IS impossible for anyone to get on this work. I have already defensively published it so now the flow monitor and control is in the public domain. It would be like trying to patent the wheel.

As for the circuit, I expect that the product would be all SMT and not use the Pro Micro at all. Really not a big deal. I wish I could say the same for the flow meter. It must be accurate over a wide range of flow rates yet be low cost. A turbine based flow meter isn't going to cut it. Might have to approach Badger and have them make a special version with a pulse output. They make some that way but the closest I could see was one pulse per gallon. I need about one pulse per 0.03 gallons. That comes out to one pulse per rotation of the nutating disk. The magnetic pick up must be Hall Effect because a reed switch can't keep up nor have the longevity. Fortunately, the body of the meter would not need to be modified.

[PJs]

Rick,

My professional experience in flow measurement & control is with Mass flow (DP/SP/temp), thermal mass flow and velocity for gasses and particulates. As I indicated before I thought your flow measurement could be done with Mass flow or Ultrasonic. Converting either to pulse output would result in a loss of all the accuracy and possibilities for control they offer.

I do still think that ultrasonic would do a lot for your system but would require considerable changes to your input and likely the code. This also assumes you are using city drinking water that has a good/relatively constant conductivity for the low flow rates.

The only other possibilities I see is a Mag Meter front end and it's also non invasive, which could be converted to pulses but would require some coils, additional power/circuits to read them and some messing around with calibration then convert that to a pulse through some kind of circuit...a comparator/inverter to (74LS121) monostable multivibrator or a couple of nor gates and RC, maybe??

The links have good +/- write ups. Also ran across this white paper on a unique Mass Flow measurement.

Not sure what type of prox sensor you tried but would think that would work. There are three basic types inductive, capacitive & magnetic in 4 flavors NPN/PNP/NO/NC....

I also took a look at the Hunter offerings and they have some nice features at reasonable prices, including 2 wire pulsed output and their controllers have wifi for decent costs I thought based on features.

Other than that, getting Badger to build it in based on your design is a plausible direction??

Best of luck with where ever you take this. ~PJ

[rgsparber]

Rick,

My professional experience in flow measurement & control is with Mass flow (DP/SP/temp), thermal mass flow and velocity for gasses and particulates. As I indicated before I thought your flow measurement could be done with Mass flow or Ultrasonic. Converting either to pulse output would result in a loss of all the accuracy and possibilities for control they offer.

I do still think that ultrasonic would do a lot for your system but would require considerable changes to your input and likely the code. This also assumes you are using city drinking water that has a good/relatively constant conductivity for the low flow rates.

The only other possibilities I see is a Mag Meter front end and it's also non invasive, which could be converted to pulses but would require some coils, additional power/circuits to read them and some messing around with calibration then convert that to a pulse through some kind of circuit...a comparator/inverter to (74LS121) monostable multivibrator or a couple of nor gates and RC, maybe??

The links have good +/- write ups. Also ran across this white paper on a unique Mass Flow measurement.

Not sure what type of prox sensor you tried but would think that would work. There are three basic types inductive, capacitive & magnetic in 4 flavors NPN/PNP/NO/NC....

I also took a look at the Hunter offerings and they have some nice features at reasonable prices, including 2 wire pulsed output and their controllers have wifi for decent costs I thought based on features.

Other than that, getting Badger to build it in based on your design is a plausible direction??

Best of luck with where ever you take this. ~PJ

Picking the best flow meter is part of turning my proof of concept into a real product. However,
I have contacted Badger about a modified meter. My hope is that they will see it as a new market.

The Arduino does have a decent analog to digital converter so a flow meter with an analog output could be made to work just fine.

The proximity sensor I tried is inductive with an NPN output. I use them on my CNC mill with good results so it really surprised me that I could not find a sweet spot on the top of the Badger meter. I did use a small magnet to map out the structure of the steel. Also tried iron filings to prove to myself there was no magnet in there.

Rick

[DIYer]

Thanks Rick! We've added your Irrigation Flow System to our Farm and Garden category, as well as to your builder page: Rick's Homemade Tools. Your receipt:

Irrigation Flow System by Rick Sparber

tags: farm and garden, electronics