somewhere to talk about random ideas and projects like everyone else



Handwriting Recognition with Microcontrollers 30 June 2015

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.

Brass Doge 10 April 2015

“We are stuck with technology when what we really want is just stuff that works.” — Douglas Adams

At MIT we get a class ring called the “brass rat”. It’s rather amusing that the ring is neither made of brass, nor features a rat. It’s actually Gold, and features our mascot— the beaver.

MIT 15 January 2013

On December 15th, 2012 12:15pm, I was accepted Early Action to the Massachusetts Institute of Technology, so I’ll be there starting this fall :)

This blog isn’t principally here to boost my ego, so I’ll leave it at that, because I’m writing this post some six months after-the-fact with a fake retroactive timestamp in order to fraud my monthly post-count goal.