CLIENT BUILD // OPEN SOURCE HARDWARE
OnionDAO Badge
A modular, programmable conference badge built for hackers. Swap RF, audio, and storage modules in the field — all powered by ESP32-S3 with a hardware secure element on board.
Status
Active Development
PRODUCT DESCRIPTION
A hacker badge built for real field use
The OnionDAO Badge was designed and manufactured by SkyRizz as a client build for OnionDAO — an open-source conference badge that doubles as a serious hardware platform. Everything from the KiCad schematics to the firmware examples is open and hackable.
Overview
The OnionDAO Badge is a modular electronic badge built for conferences and hacking events. At its core sits an ESP32-S3-WROOM-1-N8R8 module with 8 MB of flash and 8 MB of OPI PSRAM — enough headroom for real firmware projects, not just blinky demos.
The badge ships with a 24-pin display socket that accepts e-ink or TFT panels, a 6-button matrix for navigation and input, and dual 10-pin expansion headers on both sides. Three optional modules — Sub-GHz RF, audio, and extended storage — snap in without rework.
Key Features
- Swappable RF module (CC1101, 315 / 433 / 868 / 915 MHz)
- Swappable audio module (NS4168 I²S amp + SPH0641 PDM mic)
- ATECC608B secure element for cryptographic key storage
- 24-pin display socket — e-ink or TFT compatible
- 6-button input matrix via TCA9534 I²C expander
- Dual 10-pin side expansion headers with GPIO access
- Auto-reset USB programming — no manual BOOT button hold
- Peripheral power gating via GPIO18 for low-power modes
- Supports ESP-IDF, Arduino, PlatformIO, MicroPython, and CircuitPython
Hardware Specs
- MCUESP32-S3-WROOM-1-N8R8 — dual-core Xtensa LX7, 8 MB flash, 8 MB OPI PSRAM
- Secure ElementMicrochip ATECC608B — hardware crypto, I²C bus at address set via SE_EN (GPIO8)
- USB / SerialWCH CH340C UART bridge with DTR / RTS auto-reset circuit
- Display24-pin SPI socket — BUSY, RST, DC, CS, SCK, MOSI on GPIO11–14, 17, 21
- Input6-button matrix via TCA9534 I²C IO expander (0x20), interrupt on GPIO1
- RF ModuleTI CC1101 — 315 / 433 / 868 / 915 MHz Sub-GHz, swappable
- Audio ModuleNS4168 I²S amplifier + SPH0641 PDM microphone, swappable
- I²C BusGPIO9 (SCL) and GPIO10 (SDA) — 400 kHz, shared between expander and secure element
- Power GatingSS8050 transistor on GPIO18 controls the peripheral VCC rail
- Expansion28 accessible GPIO pins across dual 10-pin side headers (left and right)
In the Repository
- Full KiCad 9.0.3 schematic and PCB source files
- Production-ready Gerbers, BOM, and netlist
- 3D STEP model with all component models
- Board renders (top and bottom PNG)
- Interactive HTML IO reference table
- Firmware examples, guides, and community mods
- Detailed docs: HARDWARE.md, PINOUT.md, MODULES.md
Getting Started
- Clone the repo and review HARDWARE.md and PINOUT.md first.
- Use the production/ folder for Gerbers, BOM, and assembly files.
- Set up your toolchain — ESP-IDF v5.5.x is the primary supported environment.
- Configure PSRAM explicitly for Octal (OPI) mode using the provided sdkconfig.defaults.
- Load a firmware example from software/examples/ and flash over USB-C.
- Attach your display, RF, or audio module and start hacking.
