What if you could stream a real time hologram of an object shocked to your favorite song? And view it on your smartphone? Introducing the Shockbox Jukebox.
THE TRANSPARENT ELECTRODE
The electronics is comprised of two parts: (1) the driver circuit which converts the audio signal into a 30,000V shock and (2) the transparent electrode upon which the object is placed.
The transparent electrode resides inside the Shockbox and connects to the driver circuit via a high voltage wire. The electrode consists of a one-sided conductive Indium Tin Oxide coating, copper tape outline, transparent acetate sheets and high voltage wire.
The driver circuit was designed in Eagle. A MOSFET acts as a switch that turns on and off 12V at the positive terminal of an car ignition coil. The circuit also contains an RC snubber to protect the MOSFET from high voltage spikes, as well as a 10K resistor to ground the gate of the MOSFET.
Rather than using a song input, I made an additional driver circuit for "exploratory" mode which shocks the object at different square wave frequencies: 10, 100, 1000, and 10000 hz. I use the analog PWM output of a small Attiny44 microcontroller to do the squarewave generation.
From Eagle, I export the paths as a grayscale PNG which I then upload to Mastercam to create a mill file. I then mill out the traces from a copper board using a 1/64 inch endmill, and finally a 1/32 inch endmill for the outline cut.
Here, a preliminary test using the exploratory driver circuit going at 10hz. I was able to produce 5cm arcs with the ignition coil which was super awesome.
Once I got past the preliminary test, I wanted to try out different frequencies to see the effect. Here, a video of a coin being shocked at 10hz and 1000hz using the exploratory driver circuit.
And finally, if I could shock it at low and high frequencies, I could shock it with a song! I originally wrote a Fast Fourier Transform code in arduino to only show the real time frequency with the highest gain of the audio input, but I found that directly using the song audio input (amplified with an op-amp) was better for a more interesting response!
Once the electronics were sorted out it was time to work on the real time processing of the "hologram" video. To start, I began with playing around with image processing in python using the OpenCV module.
To create the hologram videos I needed to do the following: (1) scale down the webcam image, (2) reflect it (3) rotate it 90 degrees (4) repeat until there are four images.
Once I got the image processing to work, I needed to get started on the Server code. Essentially, I wanted to make a central computer the local host and have others connect to the local host using their smartphone web client browsers. In the web client, therefore, the users could see the real time hologram video - and ultimately, with the hologram pyramids, the hologram itself!
Putting them both together, I got a real time hologram video showing up on my smartphone! This therefore gives the users the freedom to walk around the room and see a hologram of the shocked object inside the Shockbox!
On the central computer, to start up the shockbox there are two parallel python codes that need to be running: the server code (which asks for brightness and the size of the object) as well as the music player (which asks users to chose from a selected library of songs).
THE HOLOGRAM PYRAMIDS
Once the most critical components of the software and hardware were completed, I needed to finish one last step: taking the 2D hologram video and convert it into a "3D" floating object. Online, I found a DIY hologram projector tutorial which showed how I could leverage the Pepper's Ghost Effect to reflect the video into the pyramid and make the illusion of a floating object. The three dimensionality of the object comes from the fact that it can be viewed from all 360 degrees and it appears floating in the same space.
In Rhino, I modeled what the hologram pyramids should be and what sizes they should be for each type of smart phone or tablet. I then uploaded the base files to the 3D printer and cut out the plastic sides either from an old CD case or from scratch-resistant polycarbonate sheets.
Finally, there was the box. For fun I made a small shockbox logo and a design language that connoted caution type (because of the 30,000 Volts!). Using the Rhino and Illustrator, I made the respective cut files for the vinyl cutter and laser cutter. I then folded up the box and added the stickers for completion.
And finally, a test run to the Madeon song "Finale". The key appears floating in the middle of the pyramid, with the sparks ebbing and flowing according the frequency of the songs.