A little over a year ago, my father-in-law, who considers himself a bit of a cigar aficionado, decided to give me a cigar box. Although I very rarely partake, he correctly assumed that, as a guy who loves to build off-the-wall contraptions, I could figure out something to do with it.
It took a little time before I came up with the perfect idea: Why not make the box respond to sound? As I envisioned it, the device would open up when triggered with a knock or other sound, then slam back down as if to express “his” annoyance. A little bit like Thing from the Addams Family, without the hand.
Eventually, I decided to use part of a programmable LED strip left over from another project for the “eyes.” I had hoped to make it appear that the lights were “looking” left and right, but that effect never really worked the way I wanted it to. This was probably in part because of the low resolution of my eye display, and the way I had mounted it in two sections of PVC pipe.
I did get the device to light up two colors based on the sound intensity, making it appear to understand the words “blue” or “red” -- so long as people didn't pay attention to how loudly I was speaking! Although successful, the possibilities for programming one of these strips went far beyond what I did. Maybe I will give these strips another look in the future.
Figuring out how to lift the lid was pretty easy, I simply used a standard hobby servo. I used a wooden extension to extend the servo's reach.
Although I was concerned that there wouldn't be enough torque to lift the lid, it didn't seem to have a problem getting it open. Small hobby servos are easily programmed via the Arduino Uno, which acts as the “brain” of this little device. I wouldn't call it trivial, but the actual lifting was one of the easier parts of building this device.
The most frustrating part of getting the Creepster functional was the microphone input. I had experimented with this type of microphone in the past, so I knew that I had to not only read an analog input, but also define the sample size programatically.
Another complication was the fact that having a servo and the microphone share a power source caused some interference. Eventually I overcome this challenge well enough for a decent display, but it's definitely something to consider for future projects involving direct microphone input.
One of my big fears about this setup was that the wires connecting the breadboard to the programmable strip would pull out with the lid cycling open and shut. I was pleasantly surprised that it worked as well as it did. I displayed it at the Columbia Maker Faire in 2013, where it worked for quite a while.
Eventually at least one of the wires did pull out, but I'd still consider it one of my more successful projects. It's nice to do things like this not connected with work, where there's very little pressure if something doesn't work perfectly.
— Jeremy Cook is a manufacturing engineer with 10 years' experience and has a BSME from Clemson University. You can find him on Twitter at https://twitter.com/JeremySCook
Isn't it nice that we can occasionally use technical skills for some whimsical fun? Up until now, the only tech use for a cigar box was to build a Z scale model railrod inside it. Tight curve and small locomotive, but it could be made to fit.