Thanks Jonathan for setting up the forum.
Timing is great as I’m currently browsing the internet looking a flow meters for the house so figured I’d ask here!
Does anyone use flow meters and can recommend a model? I will measure pulses using Arduino most likely pushing MQTT messages to openhab. Will likely grab something like this to do some testing.
Hi Kerry,
I have looked into using various methods for measuring I have in fact bought one that looks very similar to the one you are looking at. I have never put it in line, simply because they are made of plastic and I have some doubt of the longevity of it, and if it fails when you are not there, the water can make quite a mess.
There are ultrasonic flow meters available, but they are expensive as far as I have seen.
The last way may be to use an optical sensor that measures the light that is reflected by the digits on the display (depends on your water meter). I plan on using this method on my gas meter which has a small silver stripe on the least significant digit which makes it very easy.
HTH
David
Hi Kerry,
It’s good to see this being useful!
I did a project about this in Practical Arduino. The example code is still up on GitHub, but unfortunately I let the actual domain for the book expire and a squatter grabbed it so the only other place it’s documented is in the book itself:
Jon 
I’d like to see something for our reverse osmosis system since we overflow when filling up water glasses about once a week. I looked at the flow meter you linked but really need one for little 1/4” tubing for the RO plumbing. I would incorporate it into my kitchen controller mounted under a cabinet to flash my embedded LED strips blue while running.
BTW - kitchen control running EtherTen powered by Freetronics mid span injector.
Wow, this is awesome! So you embedded LED strips behind the tiles? I thought I was cool putting 4 LEDs behind a single tile, but you’ve taken it to another level!
I bought the flow meters for my hot water loop from amazon
I haven’t used them yet but I plan on doing the project next week. I use the flow sensor to detect hot water demand and turn on the loop pump. I have a temp sensor at the hot water outlet of the tank and a temp sensor at the faucet. My arduino sketch will be set to turn on the pump relay when it senses flow if the faucet temp is .75xT(tank)
Tf=.75Tt
so basically
F1=flow meter 1
Tf= temp faucet
Th= temp hot water heater out
R1= relay 1
If
F1=on (flow meter 1)
and
Tf< .75 Th
then
R1=on (turn on pump)
if
Tf=>.75T
R1=off (turn off pump)
I don’t actually use the flow meter to track gal/min but to indicate an on/off state although I might use the flowmeter in the future to track water usage (my room mate takes ridiculously long showers, daily). I could use a pressure sensor instead of a flow meter but since I am using an arduino for the temp sensor, this hall effect sensor seems like the perfect item. Also I like that it’s made out of brass, rather than plastic, at about the same price.
Pressure drop is an interesting idea. That might work for my application since I can’t find a flow meter for the small lines in the RO system.
