We Asked For It — An Arduino Bowel Gauge


Well, we asked for it, and [TV Miller] delivered this hilarious and surprisingly accurate bowel gauge.

Between our recent Wiping Your Bum with an Arduino feature and how to Measure Poop for a Better Sanitation Service, we guess we should have seen this coming. And you know what? It’s pretty awesome.

He’s using an Arduino Uno with a home-made resistance sensor to “hack our bowels”. After all, how can you have a proper diet without knowing exactly what is coming out of you? Two copper or aluminum strips make up the resistance sensor with a few known resistors, a capacitor and a potentiometer for adjustment. He’s even included an LCD display as well so you can see the volume of your excrement in real-time! Classy.

To see it in action (don’t worry, not that kind of action) stick around for the following video:

We particularly enjoy the use of our logo:

HackADay “Skull and Wrenches” logo used with(out) permission by HackADay.com

We’ll let it slide… this time. He’s also included the code, you know, if you’re serious about this kind of thing.

50 thoughts on “We Asked For It — An Arduino Bowel Gauge

    1. It’s noted that a valve was placed on the fill line in order to control and lower the bowel water level. This means the water displaced does not over flow in to the drain.

  1. Everything needs to be measured so no surprise here.

    So, let’s get to the science. What is being measured here? Salinity? A crude measure of pH perhaps? Am rather quite sure no matter what shape it won’t be inductive. Should use AC and stick a scope probe in that crap and see what’s going on.. err… coming out. Maybe rig up a capacitance meter to get rise time and dielectric constant, which means short leads so you’ll have to get that crap right close. I had to pause at the mention of a smoothing function and am sure you did too.

    Metal bars for a probe? Is this measured before or after extrusion? If before then bare in mind you’ve got other things in parallel that may skew readings.

    1. Despite the really bad pun, it’s actually a good idea!

      Getting the mass of the poop together with the volume of the poop enables us to calculate density. Another important variable in poop data. Imagine all the graphs you can plot with this data! <3

    2. You will need a sensors on the seat, plus a foot pad, too. When you sit with your feet on the ground, you are distributing some non-constant amount of weight to the floor, so that needs to be taken into account, too. You can try it your self. Try to stand on a scale with one foot on and one foot off. Even when you are attempting to evenly distribute your weight between your two feet, it is incredible difficult to keep it steady.

      Also any good measurement of excrement mass needs to be done in Courics, not kg, lbs, or stones.

  2. Water displacement (approximately) equals volume in this case… as long as you don’t let the sample sit too long and dissolve… (yech)
    Doesn’t account for any side sticking tho’ (yech again)

    1. I experience both wonder and distress at observation how practical and functional your mind works. Wonder due to the vivid analytic nature of it and distress due to what you must being going through on hackaday for the last couple of days.

  3. Seriously this can measure the leakage of the tank valve, as the water level may or not level out. Any rise after filling is water leaking from the tank and it wastes a surprising amount of water and makes stains in the bowl.

    1. OK… I got about 30 more good lines to post… but honestly you win! I’d much rather just see a good “FAIL” again! I lernt my lesson techur. I sowwy! I’m still seeing a palette knife “smoothing”.

      GOD MODE certainly rules tho I’m sure you got lucky finding that one.


  4. It needs a flowmeter to account for spillage over the trap as the deposit enters the water.

    That’s not bird crap on your car, the bird wants to buy it. He left a deposit on it!

  5. Im courious how you calculate the volume based on the rising waterlevel.
    in fact, souch a bowl is an nearly not calculatable container, as the volume rises not even close to linear with the water level

  6. If James would have looked at the original project site, in Uganda they dont use toilets like this, so this project has zero value for its intended target. Their toilets are more akin to holes in the floor which you squat over. But I guess asking HaD editors to do their jobs and actually read the project site is a bit too much to ask

  7. Hehehe… On the flip side, has anyone considered using near infrared to gauge turd density?

    Also worth doing (haha), measure surface composition using a laser and Raman spectrometer.

  8. Eureka ! This project is funny, but not relyable on long time.
    I think Archimède has the solution.
    If you can really mesure the quantity of water that goes away when the toilet is used, you get what you are searchig for.
    A simple weight scale mesures the quantity of water that is moved.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.