What is this site for?

It occurred to me that i had not written a post to explain what this site is for and what my Bath computer does.

So the site is to share my projects with the world. i got a lot of value out of other people’s write ups and i hope that my site can assist others.


the Bath Computer:

As home automation is one of my larger hobbies one area that i felt needed automation was my bath tub. this may seem strange but i wanted a way to start the bath and walk off and come back to a bath that was the correct temp, and correct water depth.

this was spurred on by times i let the bath run too long and it was cold or nearly overflowing.

After a bit of internet research i discovered that outside of really expensive ultra luxury devices there was nothing that would fix my needs.

It was at this time i discovered the Arduino development platform.

I had always wanted to program microcontrollers so i got one for Christmas and played around with it.

Then the bath computer was born:


it was a mess of wires but it displayed temps and changed a LED to the correct colour based on the temp.

it ultimately evolved into this with the help of our local hacker space(www.hackerspacecharlotte.com) for knowledge and inspiration and an invite to Maker Faire NC 2013 served as the inspiration:


so thats nice and all but what does it do:

well basically it fills the bathtub to the correct depth and or correct temp based on user profiles.

It will also add bubble bath if the users profile wants this.How:

  • An Arduino compatible controller with screen, buttons and Ethernet connection
  • 2 temp probes, one built into a rubber ducky that uses a second atmega 328pu to transmit the in tub temp and a second probe on the faucet to measure inlet temp.
  • A modified lysol soap dispenser filled with bubble bath.
  • Valves on the water supply.

this allows the bath to be filled remotely or locally.

its far from finished but the protoype is working at this point…..


more to come later.

Final Makerfaire NC setup rig


So this is the final rig for makerfaire NC. the duck is in the tub and i added RGB leds just for fun. this combines all aspects of the project is a portable form, as under the black table cloth is a 13 gallon tub with a pump to pump the water out of the faucet/tap.

this allowed it to be self sustained for the duration of the day.

let there be soap

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here we are hacking the lysol soap dispensers to be relay controlled.

this was fairly easy, as it worked with an IR break beam detector, so i cut the wire for the IR LED and added the port at the bottom. as it will dispense soap when it no longer sees IR we pulse the relay for 1 second and soap comes out.

i also made an jumper so it can be used as originally intended.


Faceplate and enclosure construction for Makerfaire.

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So what is a project without a box to put it in. Sometimes this can be as challenging as the design of the electronics and code.

here i took 2 radioshack boxes and chopped holes in them for buttons and screen.

the final product will be more water tight than this. Took about 2-4 hrs in total.

Below are a few early enclosures used for testing.

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Internet of (bath) things

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Here are some shots of the web interface, the one with the cell phone was the 1st attempt the laptop one is closer to the final.

It makes use of a wiz5100 chip for the arduino.


Early duck testing


So one of the aspects of this project is the duck. the Duck acts as a remote temp sensor.

it is an arduino compatible atmega 328p and a 434mhz transmitter this version has a ds18b20 as a temp probe but the final version moved to the built in thermistor.

this was an off the shelf kiddy duck:





it has 3x aaa batteries, a thermistor and a water sensor. i removed the innards and replaced it with the atmega. the biggest issue was the size, fitting in the 28pin dip and 434mhz transmitter was a challenge.





here is the custom etched pcb which fits much better than the perf board shown before.




Video from Maker Faire NC 2013

Here is some video of the Bath Computer at Maker Faire NC 2013

Back from Maker Faire NC 2013

Well we had a great time at Maker Faire NC.


The day was a complete success everything worked as expected and there was overwhelming interest and support from the attendees.


Special thanks to the Maker Faire NC crew for taking great care of us and sourcing a bath tub.


Hello world!

Who are we, what do we do and why we do it?

All will be revealed shortly