Circuit design research:In the research phase of this project, I found myself particularly fascinated with inputs/sensors that also can double up as outputs/emitters. In the previous project I was able to use a piezoelectric sensor as a speaker. For this project, I wanted to follow the same minimalist design process and find other ways to do this.
I remembered seeing a blog post from hackaday.com in 2006 that discussed using LEDs as sensors. In addition, when quickly switching back and forth between being an input and output, LEDs could be used as an interactive display. [MIND BLOWN]
Laser Command from Eiji Hayashi on Vimeo.
As with just about everything in this field, all things lead to CMU. After digging a little deeper, I found a project called Laser Command done by a former student at CMU named Eiji Hayashi. He lists some really great documentation on how he achieved a laser to LED Matrix interface.
Finally, to further reduce my footprint within the box, I wanted to things further and create my own board using the Atmel ATTiny85 microprocessor. I found great documentation from our friends at the MIT Media Lab's research group called High Low Tech.
At this point, I've successfully wired up an ATTiny programmer, upload sketches, and run the chip at 8mHz standalone on 3.7V lithium batteries. The footprint is tiny. (Picture coming soon!)
Building the boxes:I sourced my materials from the local art store and DFab down in Margaret Morrison. I used 3/16" basswood for one box and 1/8" glass-tinted acrylic for the other. To build the template, I used a site called Box Maker. I also used a digital caliper to measure the material thickness. The laser cutters down in DFab were a little worn-in and required 3-4 passes to cut through the material. This caused the friction-fit finger joints to fail and require gluing. Here's an image of it in progress:
At this point, I've got all of the components together, research complete, but I have run out of time to fully finish this piece in time. I've put up all of my documentation and research in hopes that it will help others with their projects.