Security Fest 2026 · Sweden · 2026
Source-backed RP2040 LED-matrix conference badge
Security Fest 2026's public firmware repository identifies this as the official conference badge: a small, hackable RP2040 device with a 9×9 LED matrix, six buttons, USB surface, and public firmware. The official event site confirms the completed May 28-29 Gothenburg conference, while a contemporaneous attendee report credits Carl Vargklint's badge work. Allocation and delivery are not documented.
People
A contemporaneous attendee report praises Carl Vargklint's badge work, while the Superminaren GitHub profile identifies the firmware repository publisher as Carl Vargklint. This is not represented as sole design or manufacturing credit.
SourceThe official Security Fest page identifies the 2026 Gothenburg conference and Securityfest AB copyright context; it is not a hardware-manufacturing credit.
SourceThis restores Security Fest's 2026 continuity through a concrete artifact source rather than a general badge announcement. It extends the Swedish lineage from earlier local-landmark challenge boards to a current, source-published RP2040 badge while keeping production and issuance claims bounded.
The public badge README documents a Raspberry Pi RP2040, 264 KB SRAM, 16 MB flash, a 9×9 IS31FL3731 charlieplexed LED matrix, four front LEDs, six buttons, a high-power white/IR LED surface, an IR transmitter, USB CDC, an SAO port, and marked unused GPIO. No public schematic, PCB design, BOM, battery specification, final revision, or production-test record was recovered in this pass.
The repository exposes Arduino/C++ and PlatformIO badge firmware for display states, animations, games, personalization, and USB interaction. The README also describes controller/HID-capable USB behavior. This catalogue records those public software surfaces without reproducing operational setup, IR configuration, or other use instructions.
A contemporaneous attendee said the badge was a welcoming starting point for people exploring hardware hacking and specifically praised Carl Vargklint's work. That observation corroborates its hands-on community role, but does not prove that every badge was assembled on site or establish attendee allocation.
Lifecycle
The public README documents a 9×9 IS31FL3731 charlieplexed LED matrix and four front LEDs as the badge's visible interaction surface.
SourceThe repository's public Arduino/C++ source describes display states, animations, games, and personalization for the badge without establishing a final production firmware image for every unit.
SourceThe README documents USB CDC, controller/HID-capable USB behavior, an SAO port, and marked GPIO. It does not identify a supported add-on ecosystem, compatibility list, or final per-unit wiring revision.
SourceOperational history
The record can document a real event artifact without converting the public source trail into unsupported issuance or credential claims.
Hardware detail remains source-bounded, and the catalogue does not claim that every shipped board matched the repository's documented configuration.
Source code can be linked as evidence, but no repository media or event imagery is copied into the public catalogue and the badge remains image-free.
The Sweden record remains source-backed and image-free rather than copying source-page media, documentation screenshots, event photos, social media, placeholders, or generated approximations.
The catalogue records their existence at a high level but does not publish operational configurations or represent them as tested, unrestricted, or universally fitted features.