show and tell for hackers in DC.

Round 23: Bucolic Plague

11 Aug 2015

Here are the Hackpad presentation notes from Round 23: Bucolic Plague.

Speaker #1: Eric Haengel

Infix Parser

Eric wrote an infix-parser to transform mathematical expressions into honest-to-goodness parse trees – with the full tree rendered in GraphViz. sines, cosines and even constants like pi are all fair game!

Speaker #2: Travis Hoppe

Tor Spiders

Presentation :

Code lives at:

Information online has limits, governed per-user and sometimes even by IP address. Travis leveraged the power of the darknet (specifically Tor) to spider any website with different ephemeral IP’s. What can you do with it?

  1. Scrape websites in a distributed way (getting a new IP address each time to avoid IP bans)
  2. Access control (circumvent IP range blocks)
  3. Censorship detection: does the country of origin change what content you see?

Run the code with two spiders and look at your IP address … on Tor nobody knows you’re a spider.


Speaker #3: Kate Rabinowitz

Data Lens DC

Project/Blog lives at:

Kate started a new blog analyzing DC-related data sets, and is open for new contributors!

Her most recent post Metro Delays for the first half of 2013-2015. Obvious take-away… delays are worse during rush hours than any other travel time – but she now has proof! The data came directly from the WMATA but once they heard about it they denied it. How’s that for investigative journalism!

First post: Looking at migration among cities – how migratory is DC compared to other cities? Data comes from the US Census (American Community Survey).

What’s next? Looking at the geographic evolution of nightlife in DC? Let her know!

Speaker #4: Shannon Turner

Arduino LED board

Built a working Adrunio board for the first time – end result a scrolling marque 16x32 pixels that updates live. The marquee displayed, “I have been trying to do this since July 25th” in beautiful scrolling text with bouncing circles in the background – not bad for her first hardware hack! The board let’s you load C++ programs directly into the logic board and it will run w/o computer. $60 total cost.

Want to recreate it? Here’s the Shopping list and more!

Build notes:

  1. Bought a lot of things she didn’t need for this project.
  2. Have a lot of leftover useless parts.
  3. 3.5V logic vs 5V logic is really important.

Next step: giant table LED board!

Speaker #5: Kunal Johar

Word Bubbles

Live demo at:

Code lives here:

Word Bubbles. The struggle is real!

Kunal was addicted to the game, really addicted. He even spent real money on hints! That wouldn’t do so he used the Tesseract engine/machine learning OCR to load the screen, built a solver with a preloaded dictionary of 40,000 common English words and a Twitter/web interface to solve the game.

Take that Word Bubbles!

Speaker #7: Jan Domanski

How to have lunch with Nobel prize winners* on a regular* basis

When we saw the title of the talk (as us organizers do before anyone else), one of us may have called the speaker out on his pompousness. Why? Turns out he was leveraging the power of his hacking (scripting) skills to gain access to lunch with the elite at Oxford college. In all fairness, we stand by our original statements.

Oxford college was established 1264 and has a long and storied history. As a privilege to the students, many interesting people are invited to lunch, but only on a first-come-first-serve signup basis. Turns out this opens up on Friday night at MIDNIGHT. Jan wrote a scraper using mechanize in python which provides login credentials etc… and put it on live on a AWS instance to beat the system even when his laptop was down.

Speaker #8: Jess Garson

Zine: “What’s my function”

Not software, not hardware…

Jess wrote a zine, a self-published journal… on paper!

“What’s my function” is a programming zine. This used to be a thing. Old fashioned & old-school, she literally cut and paste. From her lofty goals of high-brow content, she brought it down to a basic guide. The zine is designed for beginners and was intended to be brought to zine-fest.

Thanks to everyone who presented, everyone who attended, @svt827 and @metasemantic for the writeup, and of course thanks to our favorite WeWork for hosting!

Round 24: Hose Stable Hattery is already scheduled, so RSVP and sign up to present!