For my final project in 6.115, a microcomputer electronics class which I (and apparently nobody else) affectionately refer to as “leeblab”, I built a simple gestural input system. At its core lies an ordinary 8x8 LED matrix hacked into a low-res CCD and display coupled with a gutted expo dry erase marker used as a light pen. And per class requirements, it used a rube goldbergian cascade of TTL logic, an 8051, Cypress PSoC 5, an Arduino Pro Mini to process and massage the signals into USB HID compliant form, so that a computer might be able to use the contraption as a keyboard.

I had an 8x8 LED matrix laying around, and ‘twas the season that I had to come up with a final project for 6.115, a microcomputer electronics lab class. I vaguely recalled that an individual LED would generate a potential difference if you pummel it with enough photons. So I figured a cool and somewhat clever thing to do would be to create a display which could simultaneously act as a camera (pretty orweillian in retrospect).

I'm not totally sure about this, but I think this was the pinout of the LED matrix that I had. Notice that there doesn't seem to be any sensible mapping between spatial position and the corresponding pins

The LED matrix was something like this one. It’s wired using a technique called charlieplexing, where there’s a long wire along each row that connects the anodes of the LEDs, and another long weire along each column which connects the cathodes (modulo dyslexia).

You can imagine taking a battery and a few clips and touching one point along the row wires and another point on the column wires and see a single pixel light up at the intersection of those columns and rows.

MP3 Player - Google Chrome_014

This is my take at an MP3 player. I would consider this one of my better designs (I’m no designer or artist, and that sort of shows). It’s fairly minimalistic, a product both of my design and the fact it was created a few hours. But this isn’t about design. No, it’s a music player that operates entirely in your browser with files stored on your hard drive.

Here’s basically how it works. There’s an <input type=file webkitdirectory> so you can go and select your music folder. It gets a list of all files, reads the first 128 kilobytes of each mp3 file and parses it for ID3 tags, constructs a library and makes it searchable.

The interface is composed of four main items: a huge search bar, the music library, a playlist and the audio controls. It’s pretty self explanatory.

Here it is: http://antimatter15.github.com/player/player.html

It should work on Chrome, it might work on Safari, and will partially work on Firefox 4 (No directory select, no MP3). Definitely won’t work on IE9 and probably won’t work on Opera.