Do Nothing  Box v1.0 

5/9/2018

Many years ago while working in a hospital laboratory I spotted an old piece of test equipment stashed under a shelf.
Looked very old but had a really nice wood box. It was obviously something quite obsolete and no longer used
so I asked my boss if I could have it. He agreed but said we have to do it properly.
I brought the thing down to the personnel department and paid $1 for the “obsolete box” and was rewarded
with an official receipt.
The box stayed in one of my basements for another 38 years until I decided I needed to do “something” with it.
Well, it was very good at doing nothing for over 3 decades so let’s just enhance that.
This it became the platform for my first “Do Nothing Box”

NOTE: I recently found out that it's original function was a Beckman Model “M” pH Meter from the 1040’s or 1950’s.
It required a strange array of unusual dry cell batteries and electrodes impossible to find today, so it may never measure pH again.

If you’re not familiar with a “Do Nothing Box” sometimes referred to as a “Useless Box”,it’s a device that’s only function is to turn itself off shortly after you turn it on.
Usually a hidden mechanical device will simply flip the power switch off.
I decided to add a little flair to engage and entertain the user. (link to video)

Without removing the original electronics, I was able to put a speaker inside the chassis and add some addressable LEDs inside the meter housing.
I added a top panel to hold the “power switch” and stashed and arduino, a stepper motor and a rechargeable battery in the side compartment.

I no longer own this device since I gifted it to a fellow Arduino enthusiast before a recent move. So I can’t supply a schematic.  Here's what I remember about the circuit.
I did keep photos and a copy of the code so it would be a simple matter to re-create something similar with that info.
The board attached to the Arduino has 5 MOSFETs four drive the stepper motor and 1 for the speaker (makes it LOUD) there's a 7805 voltage regulator and a small DIP 5v relay. The relay is to keep power supplied to the circuitry while the arduino program finishes up with the "power down" part after the thing has switched itself off.

Description of download links:
DoNothingBox.ino Arduino Source Code
DoNothingBox_Video.MOV   link to video of do nothing box in action.