Sandwich enclosure
Two-part shell with a matte purple face and bright yellow base, fastened by corner hex screws — easy to open for bring-up.
Conference badges
Wearable open hardware.
Electronic badges turn a conference into a mesh of tiny computers. Study the open catalog, tear down the Three.js Conf speaker design for inspiration, then version your own board from schematic to shell.
Featured build
Three.js Conf speaker badge
Custom purple-and-yellow handheld speaker badges with a circular color display, three front buttons, USB-C, and matching lanyards. Speaker “buddies” greet nearby peers over ESP-NOW. Hardware and firmware are not open-sourced — use the visuals as design reference, then build from the open projects below.
Circular display module
Recessed round LCD/OLED drives per-badge 3D-style characters. Enclosure prototypes show a circular module on a small carrier PCB with header pins.
Front controls
Left/right navigation plus a larger yellow smiley action button under the screen.
Power & programming
USB-C on the bottom edge for charge and flash; thickness leaves room for a LiPo pack.
Mesh social layer
Each speaker buddy greets others in the same room over ESP-NOW — a lightweight ESP32 peer protocol without a full Wi-Fi AP.
Iterative 3D-printed housing
Romain spent roughly a month iterating the electronic enclosure; early prints used speckled FDM faceplates before production purple/yellow shells.
Media credits: Romain Briaux / Hervé Studio. See ATTRIBUTION.md.
Open source
15 public badge projects
Curated boards with published PCB and/or firmware. Full tables also live in the wiki markdown catalog.
BSides San Diego 2026
ESP32-C6 crypto-challenge badge with OLED, NeoPixels, BLE coop mode, and KiCad hardware by Electronic Cats.
RF Communicator Badge
RF communicator badge with MIT-licensed hardware and firmware for mesh-style conference play.
BSides Vancouver
ESP32-C3 wearable with NFC, RGB LEDs, sensors, captive-portal CTF, and detailed hardware docs.
EMF Camp Tildagon
Full open hardware + software stack for the EMF Tildagon: KiCad, docs, add-ons, and a web emulator.
Eurofurence EF28 Cyber LED Badge
ESP32-S3 wearable with KiCad hardware, WS2812B matrix, SAO header, USB-C, and PlatformIO firmware.
BSides San Diego 2024
ESP32-C3 badge with KiCad, Gerbers, wireless rock-paper-scissors, and UART CTF challenges over SAO.
TuxCon Kitty
Small OSHW KiCad + Arduino badge from OLIMEX — a compact starter for conference giveaways.
Vectorscope Badge
Analog-forward vectorscope badge with MIT-licensed design and community enclosure work.
MCH2022 Badge
ESP32 launcher firmware for the May Contain Hackers 2022 badge, continuing the badge.team stack.
badge.team ESP32 platform
Shared ESP32 firmware platform that ran across multiple European camp and hotel badges.
Hackaday Supercon 2019
FPGA SoC badge with open PCB artwork, softcore, and workshop materials.
ESP32 Conference Badge / R4ge
Through-hole friendly ESP32 badge with TFT, buttons, and MIT firmware sketches for soldering workshops.
Hackaday Supercon 2018
Retrocomputing-themed open badge with published hardware and firmware from Hackaday.
SHA2017 Badge
Foundational ESP32 e-paper badge with Eagle PCB, MicroPython apps, and the badge.team firmware lineage.
Ides of DEF CON (DC25)
Unofficial KiCad badge with schematics, gerbers, and MacroFab-ready fabrication package.
DIY
How you can build your own
You do not need a conference production line. A solid first badge is a two-layer PCB, a 3D-printed shell, and one memorable interaction.
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Choose a reference design
Fork an ESP32-C3/S3 or RP2040 badge from the catalog (EF28, BSides SD, Vectorscope, or EMF Tildagon). Keep their power tree and USB recovery path; replace the silkscreen and outline.
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Pick one interaction
Name + QR, LED mesh, SAO add-on port, NFC unlock, or ESP-NOW greetings like the Three.js buddies. Ship one delightfully, not five halfway.
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Capture schematic and layout in KiCad
Budget USB-C → charger → LiPo → 3V3, a programming header, and mechanical keep-outs for the display and buttons. Export Gerbers and a BOM you can actually order.
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Iterate the enclosure in plastic
Print sandwich shells with screw bosses (the Three.js prototypes show exactly this). Dial clearance around the round display before any colored production run.
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Write a bring-up sketch first
Flash a factory test that lights every LED, scans buttons, draws a splash on the panel, and reports battery voltage over serial. Only then layer the social firmware.
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Version and publish
Keep schematic, PCB, firmware, and STL/STEP in one git repo with an SPDX license. When it is ready, publish a public fabPlane project so others can remix it.