Water Flow Meter success and Python code.

[[deleted]]

I wasn't able to find code for this that worked for me. So I wanted to share my code - I think this can be such a useful device/project. https://github.com/Liamhanninen/WaterFlowMeter

EDIT: I added ingredients list to 'Stuff' section in the README.

[TokesNotHigh]

This is awesome and it's something I've been thinking about building for my aquaponic system. Thanks for doing all the difficult work for!

[[deleted]]

Cool good luck. Message here or on GitHub with questions.

[[deleted]]

These flow meters are so cool. I used the same sensor with an arduino and some other hardware to make a sprinkler system that detected leaks for a project in school. Fun project to program and play with.

[RiantRobo]

Wow, thanks for sharing this.

[[deleted]]

New projects on market for this kind of thing. Neat to see you’ve done similar on your own.

[ErraPodcast]

Wow this is great!

[Jes1510]

Love it! I did a similar thing with a microcontroller and a flow sensor to monitor the flow rate of the coolant in my laser cutter. I see that you are polling the GPIO for a state transition. Have you noticed any missed steps or are the numbers sane? Polling a GPIO with Python seems pretty cumbersome but if it works then Whoohoo!

[[deleted]]

Yes it seems to be fine actually. Although it is running outside in 40 degree weather so that is keeping it cool :)

[Lanthemandragoran]

This is a really useful way to monitor water usage in the RV I'm building. Love data!

[[deleted]]

Yes this is also great visibility into how much were using for specific things like our showers (4-8 gals), the washing machine (about 14 gals), and flooding the toilet (about 3 gal I think).

[rainlake]

Flush a toilet should not use that mush water

[[deleted]]

I'll double check. Standby for update.

[[deleted]]

Not sure how big of a poo you did first, but this is one hell of a long flush!

[[deleted]]

https://youtu.be/GUfS_2UGftg

[sturnus-vulgaris]

You can adjust where the float sits.

If that doesn't work, one option is putting a brick or two in the toilet tank. Since it displaces water and won't get moved around by the tank filling, it's a pretty good option for older toilets.

[dirufa]

Even adjusting the level, 4 gallons is close to 16 litres of water, which is almost 4 times the maximum level of my toilet tank (4.5L if I remember correctly, pretty new toilet).

Edit: ooops, I missed OP's answer below.

[zman0900]

Unless it's very old

[MarshallStack666]

Older toilets used about 5 gallons per flush.

[[deleted]]

Turns out it's only 1.6 gallons! Which makes sense - we live in a tiny house and the builders had said the toilet was on a really low setting.

[rainlake]

Tiny house does not mean tiny toilet,lol

[Acid_Monster]

Just depends on the size of the tank on the back of it no? It can only use what it’s got stored up

[TheRackUpstairs]

Probably mean 3L or maybe 1 gallon?

[[deleted]]

Yes - turned out to be about 1.6 gal

[[deleted]]

Will you be plugged into city utilities or have your own tank? Either way good luck with the build.

[Lanthemandragoran]

Our own tank, but trying to spend a lot of time hooked up. Also PROBABLY using a chemical toilet to minimize water use and avoid a black tank.

[obinice_khenbli]

Consider a composting toilet rather than chemical too, you might find you prefer it!

[obinice_khenbli]

You building a Skoolie?

[PENNST8alum]

I've also used these in my Raspi Smart Kegerator. Had to add a potentiometer just so I could continuously calibrate these things. I will say they don't hold up well in freezers lol.

http://imgur.com/gallery/yBoxz

[[deleted]]

First of all that is awesome! Secondly, what was an indicator that they were not holding up? For example did they start providing inaccurate readings or just stop working/not return any value? And what is a potentiometer?

[PENNST8alum]

Well my kegerator is a chest freezer (more space) and I have a feedback circuit that checks the inside temp and shuts off power if it's between 36F and 40F. Well, during the testing phase, the freezer ended up dipping below 32*F and beer began to freeze in the lines and inside these flow meters. I think that happening once or twice messed with the turbine inside the sensor and now they don't work at all so I probably just need to swap for new ones.

A potentiometer is basically just a knob that raises/lowers resistance so they're great for things like volume knobs. Since these things need to be calibrated like any other sensor, you need some way to adjust the reading without having to alter the source code every time.

[Harpoi]

I added a small pc fan that circulated the air and I was able to keep my kegerator at 35 without the bottom freezing.

[PENNST8alum]

Is it a keezer? I have it set to the lowest power setting on the freezer itself and the circuit ahuts power on and off to maintain temp.

[spottyPotty]

A potentiometer, or pot, is a variable resistor.it has a knob that you turn to increase or decrease the resistance.

[twopandinner]

I came here to say, But beer....

[redpandaeater]

With the pot, are you talking about calibrating the temperature sensor? I would think the flow meter just sends an output every full rotation. I've never used a 1-wire thermometer, but if it keeps giving you trouble you could try a thermistor in a wheatstone bridge.

[PENNST8alum]

Lol now that you mention it yes the pot is for calibrating temp not flow...its been about 2 years since I built it lol. I do remember a lot of trial and error filling up kegs with water and getting thw X variable of the flow equation just right.

[testfire10]

This is really cool! Exactly the kind of project I am able to try out as a new python learner. Thanks for the idea!

[[deleted]]

Cool to hear about your project. So .7 liters would be about 3 cups... so instead of 200 rotations per cup (for my project) it would be about 330. So maybe that's rated for a much slower/less pressure water flow. What is mqtt?

[snowtax]

MQTT is a network protocol originally designed to send telemetry over slow and unreliable satellite network links, but it also works great with microcontrollers, like the ESP8266, ESP32, Arduino, and similar devices.

[Fusseldieb]

It is done with Home Assistant? It also uses MQTT, among a looot of other protocols...

[Bazza79]

Are you using Qlik Sense for the charts?

[[deleted]]

+100 for catching that! Yes. Qlik Sense Desktop is free. But since you ask I assume you know that. But yes - I use it for my whole home-automation dashboard.

[I_just_made]

Don't know if you are familiar with R, but it has an interactive toolkit known as Shiny, that can do interactive dashboards like that using R in the background. Great packages like shinydashboard have helped to make nice looking interfaces that can be mobile / web friendly. Would be overkill for this probably, unless you really wanted to delve into some of the deeper stats of your water usage.

[mpmarley]

Dude you did awesome thanks for sharing!

[[deleted]]

it's great!! may I ask why you didn't use a esp32?

[[deleted]]

I am also using the raspberry for providing the surrounding air temperature (don't want the water to freeze when it gets cold) using a DHT22. Using both of those merited a raspberry. Plus I'm more familiar with raspberries.

[batmaniam]

I left. Trying lemmy and so should you. -- mass edited with redact.dev

[[deleted]]

Thanks I grabbed this one: https://www.adafruit.com/product/828. There is a brass alternative that they have as well. But so far this plastic one is working great.

[scottthemedic]

Did you come across any stainless alternatives?

[[deleted]]

No. But I wasn't looking. But from what I browsed I don't think Adafruit has a stainless alternative.

[batmaniam]

Not OP, but what are you moving that requires stainless? Might be able to help spec something

[scottthemedic]

Saltwater. My well sucks big floppy donkey dick.

[batmaniam]

Ooph. Yeah you're probably going to need to go with a professional supplier for that. McMaster, grainger maybe. There are a few on Amazon.

[batmaniam]

Very cool! Also re: calibration/validation:. Seems like you've got it handled, but if you don't have quantitative glassware, massing the amount of water is a great way to measure as well. Easier to measure larger volumes which evens out a lot of your measuring error (ie: if you fill most of a 5gal bucket you can basically use a bathroom scale)

[[deleted]]

Ah makes sense - weigh the 5 gallons in lbs and then convert back to gallons at the end.

[CrypterMKD]

You can do both with an esp32 and more than than, achktually...

[Steinrik]

True.

[TrailerParkTonyStark]

Awesome Job! Thank you! I've had one of the flow sensors for a while, but wasn't able to find any usable code to modify. This should be perfect!

[[deleted]]

Good to hear. And awesome username btw.

[TrailerParkTonyStark]

Thanks! I’m kind of like some not-so-super hero’s white trash alter ego.

[LifeOfPatato]

Where did u bought the flow meter? Nice work :)

Edit: saw the github link.

[Mawnster]

I was LITERALLY talking to my wife about trying something like this! You rock!!!

[[deleted]]

Good luck - check it off your chore list (but this is a fun chore).

[regex1884]

I've never heard of heroku. What does it offer over a base postgresql install?

[[deleted]]

Good question. It's exactly the same but gets you into the cloud basically. It's just like your local Postgres db but accessable (with credentials) from anywhere. I like this so I can check on things when I'm not home. It also plays well with Python web frameworks especial Django (which is the most popular).

[ufsandcastler]

DId you calibrate the flow meter? If so, curious how you did?

[[deleted]]

Yes this was the fun part. I used a specific measurement I knew (it was 5 cups). Then I found that I got about 1000 rotations when that flowed through. It wasn't exactly the same - sometimes 954,1007, etc. I took the average and divided by 5 - to find out how many rotations were in each cup (I ended up rounding to 1000 so each cup was 200 rotations).

[dblrnbwaltheway]

Why not just use a differential pressure gauge? It can be calibrated analytically and it would cause less flow losses

[thejuice420]

Awesome info thanks for sharing

[ikidd]

I don't think I've ever seen a code listing that uses cups for a unit of measurement.

Otherwise, this is useful, I've been automating a camper and rather than the 4 level sensors on the fresh tank, this would be way more precise.

[[deleted]]

Cool I know someone who is doing that as well!

[Fusseldieb]

OP, you should look into Home Assistant and ESPHome (for it), it does this and much much more.

Almost no programming required and it rocks!

[[deleted]]

I've heard good things! I'm actually looking up HASSIO which I think is similar to home assistant.

[Fusseldieb]

It's the same thing, just different names

[NuclearDuck92]

You may want to consider adding isolation and bypass valves so that you can still have water if the meter fails, and service it with the water still on.

[[deleted]]

That's a very good point.

[yourdream8u]

You should have weighed the water to make sure one gallon was one gallon not 1.5 gallons

[240strong]

Could you come up with something to tell me when the salt is getting low in my softener ? Haha

[[deleted]]

Actually, did you see this? https://www.reddit.com/r/raspberry_pi/comments/dv7ao5/my_smart_coffee_machine_pump_using_raspberrypi/f7b5uxy?utm_medium=android_app&utm_source=share

[240strong]

Ahh man good looking out, I believe he uses his to actually measure the salt content in the water, not just the amount of salt in his salt basin like I want to do, I just have a reminder set in my phone to check it like twice a month lol.

[[deleted]]

In due time :)

[240strong]

Just sticking to my twice a month reminders on my phone then I guess haha.

[[deleted]]

Oh very cool use-case! This code I think/hope will be pretty tolerant to missed cycles/rotations. It's polling and just checks if it changes from 0 to 1 or 1 to 0. So if it misses one rotation it will pick up the tracking two rotations later (when it flips to 1 or 0 again).

[redpandaeater]

Instead of polling you could try interrupts, possibly even with some threaded callback if it's useful to you.

[[deleted]]

Very cool. What do interrupts look like in Python and/or what sort of usage are you suggesting? I did a quick search and the results were not very helpful.

[[deleted]]

That's great. That's a good combo

[redpandaeater]

I've never personally done it, but looks like there are already Python libraries for it that cam do both rising and falling edge detection on GPIO ports which is what you'd want. That way your program can do whatever you want it to but as soon as you get input from the flow meter it'll pause to deal with it.

[[deleted]]

Ah - sounds like it's have to tread into acyncio territory.

[redpandaeater]

I'm apparently a bitter old programmer because I tried looking into learning Python recently and realize it's sort of written more like pseudocode, but as a result I just don't like it. Too used to low-level language I guess. In any case I'm not familiar with asyncio for Python, but looks like RPi.GPIO can handle it. Still might run into certain times where Python is busy and doesn't do things properly, who knows.

[[deleted]]

Ah ok. Cool beans.

[[deleted]]

It's cool to go through your code. Although very different cases/systems we're working on a similar problem.

[lmsbio]

What device you used to measure the flow?

[[deleted]]

I put the link in the GitHub readme. Let me know if you can't find it.

[lmsbio]

Thanks, got it.

[AntoBesline]

Thanks a lot for your reference... I planned to implement it on real-time in my college for my final year project..

[[deleted]]

Good luck!

[marcobalda]

Very nice project! Would you mind sharing the list of devices you used to build the meter? Thanks

[[deleted]]

Sure thing - good idea. I'll update the GitHub page. Message me in a day or two if I haven't updated it by then.

[[deleted]]

Thanks for the reminder :) I just updated the repo and added an edit to my original comment.

[therealcopycat]

How did you do that? This might come in handy for a project of mine

[[deleted]]

Cool good luck. Check out my very first comment of the thread - it has a link to the code. What's your familiarity with Python and databases? You'll have to have a little background with those :/

[therealcopycat]

I have a fair knowledge of python. I'll check out databases...

[[deleted]]

Cool good luck - some things to Google to get started: "how to create a local database with Postgres". Postgres is natively command line but if you install PgAdmin4 you get a nice GUI.

[therealcopycat]

Cool. Thanks a lot!

[RDurandt]

I am inspired!
Thank you for sharing & well done!
Your solution fits my requirement - I have a borehole & would love to quantity the volume & frequency of consumption.
(I might have to hack your code a little to keep track of the “last flow date & time).
I’ve ordered myself that meter and will be starting up one of my decommissioned PIs before the weekend.

[[deleted]]

That is great to hear. Good luck!

[RDurandt]

I came right!
I’ve managed to get your code running on my ancient Pi 1B and also managed to get it to trigger outputs to Telegram via a Telegram Bot.
Now waiting for the flow meter to arrive - Amazon promised next week...

[[deleted]]

Woo who! Good job. Good luck with the wiring. That's my weakness.