Low Cost Water Flow Sensor and Ambient Display

Water is a precious resource. Millions of people do not have access to clean drinking water, and as many as 4000 children die from water contaminated illnesses every day. Yet, we continue to be wasteful with our resources. The overarching goal of this project is to motivate more sustainable water use behavior and raise awareness about global water issues.

This is an instructible on how to crudely detect water flow in a pipe and drive an ambient display. I am using a piezo transducer, some LED's and an arduino. The device is a rough prototype of what will eventually become a persuasive technology that motivates sustainable behavior and raises awareness about water use.

This is a project by Stacey Kuznetsov and Eric Paulos at the Living Environments Lab, at Carnegie Mellon University Human Computer Interaction Institute.

Produced by
Stacey Kuznetsov
[e-mail]
http://staceyk.org

Eric Paulos
[e-mail]
http://www.paulos.net/

Living Environments Lab
http://www.living-environments.net

The video below illustrates a previous version of this project, where a microphone is used instead of a piezo element to detect water flow. You will achieve better performance when using a piezo transducer, so this instructible details the piezo approach.

Special thanks to Briam Lim, Bryan Pendleton, Chris Harrison and Stuart Anderson for help with ideas and design of this project!

Step 1 Gather Materials

You will need:

- Breadboard
- Microcontroller (I used an Arduino)
- Mastic
- Piezo Transducer (http://www.radioshack.com/product/index.jsp?productId=2062402)
- A few LED's (I used 2 yellow, 2 red, 2 green)
- Candle holder or similar-sized container
- Wire
- 1 Mohm (or other large value) resistor
- 4.7K Resistors (3)
- 1K Resistors (1)
- Low-value Resistors (for the LED's)
- Clipping Wires
- Jumper Wires
- Mastic
- op amp (LM613)

Comments

[albiemorkal]

hmmm..good

[Sol501]

I think it's a little sad that you didn't put a watering pot or something under the faucet when demonstrating your little idea... but the idea itself is great - i think it's verry important to save as much water as possible!

[222fbj]

fyi - see 'DIY Arduino Water Meter' at http://labs.teague.com/?p=722

[Yong2010]

Cool.

[powerfool]

Well done!

I've been thinking for some time now to create something like that but I didn't know the way, I didn't think about piezo. I will try to make something that measures how much water passes the tap and displays that on a 2 digit display. I think to actually see the number of litres that are being wasted is more shocking. But I still haven't figured how to measure the quantity of water passing through...
Anyway,
great implementation! Well done!

Dimitris

[thread_soul]

 It is possible you could use the piezo/vibration method here.  I would guess there is a correlation between the vibration level with the water pressure / flowrate.  You could find out by opening the faucet a small amount, record the signal voltage level from piezo circuit then collect and measure the amount of water that came out in a defined amount of time.  Increase the opening of faucet and repeat.

After this you have data relating the vibration signal level to flow rate (volume/time).  If it is linear relationship, you can interpolate/extrapolate a function to create the readout.  If not linear, but is still structured and not random, you can quantize the vibration level depending on how accurate you want the flowrate readout.

could be an interesting way around the usual methods of flowrate sensing, which aren't typically very suitable for small-scale unobtrusive projects.

let us know if you do anything like this, it would be interesting to see the results, I myself would use something like that.

[Emperor Dane]

wait, is this the same stacyk from News SH? awesome instructable., really well done. as an alternative to an electret mic, you could also use a headphone speaker as a microphone. i'm so going to put one of these in my apartment. and integrate usage over the course of the day, VU meter style Dane dklabs.co.nr

[trike road poet]

be aware that in an apartment, you will be detecting the vibration from your neighbors water use, as well as sampling some of the vibration of the in-wall heating systems, (some systems are so close together you may get a bleed-over effect, especially of the heating system is hot water and uses zone pumps.)  you might want to wrap your pipes where they come through the wall with a lead collar, or use mastic (RTV) to seal the pipe and the wall so that the house structure dampens these extraneous vibrations and gives you an accurate reading of just your usage.

[staceyk]

HOW do you know News??

[Emperor Dane]

Actually, a DJ at RPI GZ informed me of it like 3 years ago and i have a rather good memory of names and numbers. Kinda odd, but then again im an EE.
Regardless, awesome instructable!

-Dane
http://electronics.union.rpi.edu/

[staceyk]

oh wow, small world :) Thanks for your feedback!

[Emperor Dane]

so, where do i get a tshirt? :)

[misteravocado5]

I like the idea a lot, but I don't have an arduino on hand, so it wouldn't be all that low-cost for me. So I was thinking: couldn't you have a wire on either side of where the water flows out of the faucet (so that when you turn on the water, it completes the circuit), connected to a 4017 decade counter IC (one of those things that counts to ten at a set rate and costs less than a dollar). Hook that up to some LEDs and you have a less advanced but functional version of this. Maybe there's some reason this wouldn't work, I'll have to try it, but it seems to fit my needs more.

[askjerry]

This really needs to be entered ASAP...

http://www.refresheverything.com/

[OhioUB]

Your invention was great, but I am not a tech guy.  Has anyone picked up on your idea to sell them?

[baezl]

 Hey I really liked your project so I wanted to try my own. I think I have all my parts write but its not working. Can you help me out? 

[Stefan_Hermann]

Very nice project. I like it a lot and hope, it will inspire more projects in this direction. Only one point to add. Instead of using fotos from the bread-boary, you can use sketches from Fritzing (you can get it for free on fritzing.org for any plattform).

[koendevoegt]

I don't seem to be able to find the code that actually steers the LEDs. Can you please provide the entire code. (Or point me to what I've overlooked) I'm an arduino n00b...

[pavan5859]

nice way to detect water flow and now i want to use a temperature sensor also using arduino so that i can run the pump to get rapid hot water its a small project im doing in my coll and i m running out of time ........ can u plz suggest me with the sensor and the relay for the pump or anythng else

[Geek506]

Great inst. Thanks for sharing.

[greaser]

Isn't this why beer was invented?

[nolte919]

This is a really interesting idea. I was just looking for a flow sensor on Google and I can't seem to find one for less than around $100. It seems a shame to pay so much if all you need to know is if water is flowing or not rather than actual flow rates. I have a few questions at a matter of clarification. You list parts and you have a schematic but you don't say what parts go where. I'm curious in particular about the resister values, R1, R2, R3, R4, R5. And is Q1 the Piezo Transducer? I can think of a couple applications where this idea would be quite useful.

[nolte919]

In one of the pictures in step 2 you do indicate resister values but that only leads me to further confusion. Did you mistakenly reverse the labels of v+ and v- on the opamp input? If those are labeled correctly then I am super confused.

Given that the labels of v+ and v- are reversed in that picture than these are the values:
R1 = 1M
R2 = 4.7k
R3 = 4.7k
R4 = 1k
R5 = 4.7k
Q1 = piezo transducer

Not to get nitpicky on you but you might change the schematic so there's a dot between R1, R4 and Q1. The way it is now it looks like the wires cross over each other but to not connect.

[staceyk]

Yes, you're absolutely right, the V- and V+ were mislabeled in the image. Thanks for the catch!

[danretus6]

Hi staceyk, I like your project. I want to know which type of piezo transducer did you use. I went on radio shack website but I cannot find the piezo transducer.

[conrad2468]

if you have a counter sink.....drill a hole that the wire can go down and install the arduino under the sink

[Sparkington]

Maybe you should rig a solenoid to incoming water supply to the tap so when the red light comes on. It automatically turns off the water so you don't have to. There for saving water for people ignore the warning red LED. Great project anyway.

[watchurmouthyoungman]

good idea but its not that good looking... :( make it where like the the color of the water actually changes! thats always cool.. where the LEDs like point toward the water and cooooolll stuff.

[disgruntldtoad]

That would actually be a pretty good idea, and probably rather easy to implement. How ever, I would think it would take some bright LED's to illuminate the water in the daytime, so maybe buying a much brighter multi color LED and just working with it instead of a few of them.

[gamemasterful]

That and seal all the circuitry and LEDs in some sort of clear sealant like hotglue, epoxy, acrylic, etc. Or if you have a clear sink bowl have the leds diffused under it to illuminate the entire bowl. That'd be cool.

[Simpson_jr]

/serious mode off Can't you charge the water with a lot of volts when greedy users abuse the tap ? That will teach 'm ! ;-) /serious mode on Sorry, I couldn't resist it (don't try this at home...). I think it's a great idea for saving water on all kinds of locations... A friend of mine is high tech botanist on a low budget basis, with a few adaptations this could be exactly what he's looking for.

[balam]

very nice I am wondering about the liking in of water and shorting the circuit that could fry the arduino board. how do you make this water proof

[thatmantheuser]

silicon

[airwelldriller]

Some air wells built by Neolithic men are still producing. (Huge bang per buck!) In the last three years I have found references to air wells in France, England, Lithuania, Afghanistan, Persia, China, and the South Pacific. Air wells work by taking advantage of the fact that different materials and structures heat at different rates during the day and cool at different rates during the night. The Russell air well - patented in the 1920's - produces 25,000 gallons a year in a 30' x 30' concrete structure. The air well discussed in "Naturalist on the Thames" produced about 219,000 gallons per year, but the writer did not tell its dimensions. Evidence of working air wells is visible to all of us; dew spots on our windshields, frost on our roofs, the need to de-water utility tunnels and well pits that have no detectable leak, the musty smell in "dry" basements. The simplest air well is simply the 12' wide by 4' high pile of rocks that the Afghans use to water a newly planted tree. (What does a newly planted tree in the desert require? A couple of gallons a day?) Air wells are called air wells, dew ponds, ship ponds, mist ponds, cloud ponds, fog ponds, rock piles, gravel mulch... and in my opinion a cistern is probably an airwell, too. My study suggests that if the money put into 450 miles of Interstate highway were put into low-tech airwells (insert lots of if's, but's, and maybe's) it might produce 72% of Denver's current annual water requirements. Would you like to see an Instructable on a desktop (high-tech) model that I built that produced about a teaspoon of water between 0001 hours and 0500 hours... but the had water evaporated by 1000 hours?

[niceday8888]

Thank you for explaining air wells, I learn something today. I love reading the comments there is so much to learn from others.

[PyroMonger]

you should add a buzzer to the circuit that buzzes once wen the light turns yellow and then has a continuous buzz if the light turns red to warn people to turn it off

[omkar_hummer]

you wasted much water while testing your device!!

[teamcoltra]

I understand the need to conserve water, although I live RIGHT ON TOP of an aquifer... Because when other states are in drout we ship our water to them (typically CA)... I wish this would focus more on our OWN need for water rather than people in another country. People are soo worried about people in other countries but in all honesty we are in some serious crises here that we need to take care of first. That being said: Very good Instructable, people keep putting the message before the well written "how to" article this is supposed to be.

[Indigno]

Since when do we ship our excess water to third world countries? It's not like the countries that don't have clean drinking water are down stream from us. The only thing that is saved by this device is one's own personal water bill.

[rerat]

preachy. I was interested in this project until I started the video.