Hacker Hotel attendees weren’t given just any old badge and lanyard this year; they were adorned with an RP2040-based piece of artwork that not only sent you around the hotel to find everything, but also tested you with a few on-board games.

RP2040 is the brains of this event amulet, with a CR2032 coin cell powering everything. The top third of the badge carries the circuitry and the lower two thirds has a row of buttons and LEDs which do lots of fun things. More on that later.

Deep dive into the design process

The badge building team Nikolett, Sake, and Pim took to the stage at Hacker Hotel to talk about the design and logistics of the conference’s smart badges. Everything is spectacularly open source and you can find it on GitHub.

Is it a badge? Is it a gaming device? It’s both!

The team made a game that sent attendees on a treasure hunt around the hotel to find codes to input into the badge using the shift register. A challenge-response game was also preloaded onto the badge, with increasingly difficult puzzles for the wearer to solve. It starts out quite simply by asking players to repeat LED patterns, but gets harder with bit shifting and ASCII tables.

Top-tier gamers who finished the treasure hunt or the challenge-response game could enter the computer code printed on the lanyard — the design that looks like punched tape in the first photo — to access a special bonus adventure-style game played via USB serial.

Fashion as well as function

Ancient stone tablets and gravestones inspired the intricate artwork on the badges. The team went method and created a backstory involving a weird computer company in the 1960s who decided to combine ancient magic with modern technology to create a supercomputer. The final design looks like a tablet with ancient text and symbols on one side, and like a computer on the other.