Textolite instead of cardboard. A few words about the OFFZONE 2019 interactive badge
Where does the conference begin? Of course, with a badge! This is the first thing you get at the entrance, all day (or several) you are inseparable from him, and then he hangs above your table, reminding others of your cosmic steepness and professionalism.
Therefore, we try to make the badge for the international conference on practical safety OFFZONE memorable. 2018 OFFZONE badges were full-fledged computers based on an 8-bit processor with JVM on board. And at OFFZONE 2019 (June 17–18), the role of the participant’s badge was played by an interactive printed circuit board, made in accordance with the general style of the conference, in the form of a 3.5-inch floppy disk. Oldies here ?!
Each participant in the conference received a badge and a set of four AAA batteries upon registration. You insert batteries - the badge joyfully greets you with a carousel of all the colors of the rainbow.
Badge was pleasing to the eye and collected likes on instagram, but this is not its main functionality. Even in the basic version, it served as a wallet for OFFCOIN - the official currency of the conference. She was received for solving various tasks and exchanged for a branded merch.
The “basic delivery” of the badge included a microcontroller with the necessary harness, power system and IR transmitter. This is already not bad, but sometimes the soul requires a holiday. In this case, the badge had hidden opportunities.
The first rule of an IB conference is that you can break everything, including badges. We did not depart from tradition, but modified it a bit: in order to crack our luminous circuit board, it had to be repaired first - solder the missing electronic components with our own hands.
You could find out about all badge upgrades in two ways. The first, for the attentive, is to study the instructions on the conference website . The second, for the impatient, is to interrogate some of the organizers at the site.
Both methods led participants to the soldering zone. And then the fun began! Solder coils, the smell of flux and other joys previously available only to amateur radio enthusiasts.
5 steps to a tuned badge
The first step to upgrading the badge was to solder the DIP Switch into 8 switches and 8 R8-R15 resistors with a nominal value of 220 Ohms and size smd 0603 on the opposite side of the board. DIP Switch made it possible to switch the badge operating mode, and also opened access to the first task.
In the first task, it was necessary to set the lower four bits of the switches in such a combination that all four LEDs were lit in green. As soon as this happened, a USB badge sent a flag to the participant via the COM port.
A little explanation for those who did not manage to get into the soldering area at the conference and want to repeat the trick at home. The top four bits of the switch determine in which mode the badge will start after a restart. The position of these switches should be interpreted as representing a binary number: the eighth switch in the ON position is 0001, the seventh ON is 0010, the eighth and sixth ON are 0101, and so on. Tusky numbers were from 1 to 5. State 0 - wallet mode OFFCOIN.
For the second task, it was necessary to mount a tiny 0.96-inch OLED display with I2C interface and a couple of jumpers. This task can also be reproduced not only on the OFFZONE site, so here is the instruction.
Everything is simple. The display is the PLS-4 connector, and the jumpers are the resistors R2 and R5 of the smd 0603 frame size. We soldered, selected mode 2 on the DIP Switch, restarted the badge, waited for the program to complete loading, passed the epileptic test and now you can play Flappy Quote.
The purpose of the task is to pass 1337 gates with a quotation mark and not die. It is not so easy to do this with your own hands. However, if you connect via a COM port to a badge in Flappy Quote mode, you can see a lot of useful information - it’s enough to write your bot! The goal in 1337 gates does not look so awesome.
At the third step, it was possible to solder a simple TSOP38238 IR receiver, find the badge set by the organizers in the soldering area and accept the package that was transmitted there. The parcel turned out to be a 7ZIP archive, which contained the compressed FAT12 file system. It was necessary to delve into it and find the flag.
Then the participants could solder the RC-522 RFID transceiver, in the zone with tasks for hacking IoT devices, find the marked pass card, dump it, dig into the dumps, notice some interesting features in them, correct the data and write to their blank card. If everything is done correctly, the map check on the IoT zone was successful and the participant received a flag.
For the last assignment, we had a 433MHz radio band and two modules: a receiver and a transmitter. With the help of the radio, chat was implemented for all owners of these modules, as well as the search for the source of flag transmission constantly piling back and forth. You just had to walk on OFFZONE, stare around and catch radio packages. One of them contained the desired flag.
The last three tasks can no longer be completed - the necessary conditions were only on OFFZONE. But if you want, you can always complete the modification!