The ZaCon badges were a ton of work on the hardware side (see ZaCon V Badge [1/2]: Build Time), however they provided their own challenges on the software side as well.
Since my knowledge of chipsets only extended to the Arduino the badges are essentially a complete Arduino without the UBS->FTDI breakout. This means that each badge includes an Arduino bootloader which is _really_ nice if you are coming from an Arduino background or simply have an Arduino and want to play.
The idea behind the badges was that they would provide a means of tracking communication between individuals at the conference. Additionally I wanted this information transmitted to a central location so that it could be stored and visualised (yes yes, Maltego and all). Additionally because people would be moving around I needed to create a ‘mesh network’ of sorts so that anytime someone came into range of any other badges they would be automatically be part of the network. This blog entry is going to cover how the badges did this and the challenges faced, if you are not interested make like a heartbleed and go away.
Here is a video of a few of the black badges communicating to each and flashing for all the valid messages received:
I realise I should have done this entry a little sooner, but as everyone should be well aware of by now, I am lazy. Also I moved to Cape Town just after ZaCon V which proved rather time consuming! Please note this is gonna be a first of 2 big entries on them so if you don’t like reading, pull up now.
One of the highlights of the annual Las Vegas pilgrimage for me has always been the electronic badges, whether it’s for defcon, ninja networks or custom badges that people have built for their hackerspaces. I especially enjoy the ones that are a little more complex (more than just lights) and are hackable. I have always been in awe of security researchers such as Adam Laurie, Zak Franken, Michael Ossman, At1as and the other hardware hackers.
For ZaCon V ( www.zacon.org.za ) I built some electronic badges for the conference that are based on an Arduino framework (at least using an ATMega328 with an Arduino Bootloader) and communicate to each other via 433Mhz RF (the same that is used in remotes). The idea with the badges was to have a way to see who was interacting with whom and show it in a visual representation (Maltego — yes yes, man with a hammer etc). Additionally I needed the badges to be cheap as.. well… I am cheap :)
The badges took about 3 months to go from breadboard to finished and a large majority of that time was spent learning how electronics work (and don’t!). This however was not my first attempt at building badges, for the last 3 years I have built a design on a breadboard and then basically done nothing with it (apart from make a shakey cam video at 3am and suggest the idea).
A lot of the design actually came from me wondering around hobbyist electronic stores on the internet and coming across two really cool things namely, very cheap communication in the form of 433mhz RF chips and Nokia 5110 LCDs (also cheap :P ).
I ordered a few of the screens and RF kits and started tinkering- having a display connected to my Arduino brought all kinds of warm and fuzzy feelings. Next I started playing with the 433Mhz, originally thinking that the badges would only receive a simple message, something like who was currently speaking, from a PC near the stage. Roelof looked at it and suggested that this idea was boring and if I really wanted to do something cool I should make all the badges talk to each other. And so the tinkering began.
Its taken a lot of motivation to start writing this, and I hope its okay, I have a mental block that I need to write this and the second post about magstripes before moving on to some new things with my plants I want to try.
My friend Roelof Temmingh (@Roeloftemmingh) made this cool video for my talk, check it out below or at http://vimeo.com/51228567. Please note we had permission to test out the door at Senseposts’ old office :)
Not the quickest of cats
on the best of days.