Picture of Arduino Compatible Bathtub controller

Lets start with a warning: this project controls water. Electricity and water really don't mix and there is a real risk of electrocution and or death if you are not careful. Build this project at your own risk and I won't be held responsible for anyone who builds this. make sure you use a battery to power this NOT a mains transformer of any kind. just be smart and be safe.

Any and all damages/injury incurred by the implementation of the information in this publication are the sole responsibility of the end user, I cannot accept any responsibility.

What is this? it is a arduino compatible (ATMEL 328p) based home bathtub controller.

this controller sets the depth, adds bubbles and monitors the temperature of a bathtub based on a user profile. v2.5 has support for Internet of things but it is not fully implemented.

But why? Well why not? ever wanted to have a bath ready at a touch of a button or from your smartphone(coming soon)?

Well now you can.

Basically this is an arduino compatible board that switches 3 relays, monitors the inlet temp with a DS18b20, the tub temp with a second arduino compatible board remotely via 434mhz and adds bubble bath via a hacked automatic soap dispenser. Version 2.5 will have wiznet Ethernet support.

This project was at Maker Faire NC 2013 & 2014 and was a hit.

Here is a video from Maker Faire NC 2013 where we had a full size demo going:

this is also my 1st instructable.

acklenx1 year ago

You gutted a duck in an Instructable. You, sir, are awesome!

raptor_demon (author)  acklenx1 year ago

i censored out some of the images for the more sensitive viewers. ;)

Machine1 year ago

Do you really need your ID around your neck while in the bath?

raptor_demon (author)  Machine1 year ago
No, that was my maker faire exhibitors badge and it is unrelated

No Ducky!! Just kidding, cool Instructable :)

raptor_demon (author)  TrollFaceTheMan1 year ago

Thanks! I feel the duck really added to the project. the kids at Maker Faire NC loved it.

tmack01 year ago

Awesome! I had a similar idea several years ago and it actually won me a contest, but never got around to actually building it (the contest was just to write about an idea). Glad to see someone else did


raptor_demon (author)  tmack01 year ago

Now that is funny! I never even saw that before making this. congrats on the 1000usd win.

xotan1351 year ago

I have utilized a little item which I call a stock tank filler. It's purpose is to let the tank fill until the preset level. It just clips to the side. You might look into that type of tech.

raptor_demon (author)  xotan1351 year ago
Thanks I'll take a look, do you have a link of one you have used?
raptor_demon (author)  xotan1351 year ago

this is cool, this would make a great safety feature. the only issue i can see is it would need to be moved for each person using the tub (as different people need different fill depths)

I have considered building a shower like this. One feature you might try to incorporate is some sort of automatic user recognition, for the 'get out of bed and blindly stumble to the shower' use case. This could be done by integrating a weight sensor into the tub/pan to trigger it. Combining past weight data with timing info may be able to adequately differentiate between multiple users, even as the weights and routines themselves change.
totokan1 year ago

This is a good starting point to a cheap but powerful clone of those digital shower controllers that go for upwards of 700$...

raptor_demon (author)  totokan1 year ago
Yea it could easily be modified to so something like that. Temperature mixing is the next hurdle, but I can't do that without removing my bathtub. Maybe some day I'll get to that