I'm working on a lawn irrigation project which uses a Arduino At Mega 2560 controller with two SainSmart 16 channel relay boards. This configuration will control the watering for 26 different lawn irrigation zones.
I'd like to add the ability to measure water usage in gallons with this project. Unfortunately, I can't find a suitable water sensor (meter) for my project. I did find the Seed Studio meter Seed Studio Meter But I don't think it is suitable for my project which will be running about three hours each day. The Seed sensor looks as though it couldn't handle this type of volume. Also, it would have to connect to a 3/4 inch water pipe.
Hi, I am working on a similar project, and also plan to incorporate a water sensor, both to measure the amount of water used and also to be used as a safeguard to detect any water usage when all the sprinklers are (meant to be) off.
I plan to use a similar one to the one you mention, it is spec'd to 8 gallons / minute, so I think it should handle the volume OK. There are a number of similar 3/4" units on eBay that are spec'd at 16 gallons / minute and 175 PSI for around $5.
These units aren't calibrated per se, but it shouldn't be too difficult to calibrate them with a container of a known volume.
BobS0327:
I did find the Seed Studio meter Seed Studio Meter But I don't think it is suitable for my project
It should be fine. They are robust, reliable, and easily implemented. Larger ones are available on eBay at only slightly greater cost but may be unwarranted as a 1/2" unit should be good for about 30 litres/min. They usually come with a calibration factor, ppl, and you can tweak that in your programme if and as required.
Google Jaycar Freetronics flow gauge for a programme. The devices can be very accurate but, if you want readable flow rate, I think you need to average it readings over several seconds.
I'm on city water and my monthly water bill is determined by the number of gallons I consume. Using a gallons measurement would allow me to calculate the cost of watering my lawn.
Also, I initially judged the seed studio sensor by physical appearance. My thinking was that a plastic valve may not hold up under a lot of daily use as opposed to something like a brass sensor. I guess I can't judge a book by its cover. Will pull the trigger on a 3/4 inch sensor.
BobS0327:
I'm on city water and my monthly water bill is determined by the number of gallons I consume.
I'm afraid that sensors are made for the world market and not for those few countries woldwide that still use archaic "traditional units" instead of SI units.
But the solution is simple:
get a sensor that measures flow in SI units, or derived from SI units like "litres"
then measure "litres" in your sketch first and finally calculate to the unit you like best just before displaying the result
jurs:
I'm afraid that sensors are made for the world market and not for those few countries woldwide that still use archaic "traditional units" instead of SI units.
But the solution is simple:
get a sensor that measures flow in SI units, or derived from SI units like "litres"
then measure "litres" in your sketch first and finally calculate to the unit you like best just before displaying the result
This is just pompous nonsense. It implies an arduino reads a meter. But arduino is the meter and all it needs is a sensor. A sensor delivers an output in pulses according an input in volume. The choice of units irrelevant and merely a matter of counting pulses and applying the desired conversion factor in the programme. The idea of measuring litres first is absurd.
Nick_Pyner:
This is just pompous nonsense. It implies an arduino reads a meter. But arduino is the meter and all it needs is a sensor. A sensor delivers an output in pulses according an input in volume. The choice of units irrelevant and merely a matter of counting pulses and applying the desired conversion factor in the programme. The idea of measuring litres first is absurd.
Are there manufactures still active on the US market creating sensors that create "pulses per gallon"?
China has switched to SI units many years ago (such like most other countries in the world) and cheap flow sensors from China always count flow in "pulses per liter".
What I wanted to say is: If you want to have a display in archaic units, you don't need a sensor that is archaic the same way, but you can easily use a modern sensor that counts flow with "pulses per liter", and although you are counting litres then, it is easy to calculate any archaic unit from the litres you got from the modern sensor which operates on SI units only.
Nick_Pyner:
The choice of units irrelevant
Exactly. You can easily use a sensor that measures SI units, but from that you can calculate archaic units for the display.
The TO doen't have to search for "a sensor (meter) to measure water flow in gallons", as he wrote in the topic. Any other sensor measuring litres will do.
BobS0327:
Also, I initially judged the seed studio sensor by physical appearance. My thinking was that a plastic valve may not hold up under a lot of daily use as opposed to something like a brass sensor.
It should be fine. I think they are typically quoted at 175 psi and your local supply is likely to be well under that, but it is something you should check. They have only one moving part and, providing it is not abused, it is reasonable to expect the service life to be about the same as that of the supply authority's meter.
weedpharma:
Maybe the reference to litres was a little tongue-in-cheek?
Who would know?, Weed, but it read like rubbish. One thing though is that, while one of my sensors was quoted in pulses per litre, I recall it actually worked out to a nice sensible 25 pulses per imperial gallon. SI is as SI does, as they say. Perhaps the design was done by some old guy in Stoke-on-Trent.