

Rfboard
Small blinkenlight boards that sync up using radios
- Size
- 21 × 63 mm
- Copper layers
- 4
- Thickness
- 1.61 mm
- Parts
- 67
- Nets
- 53
- Pads
- 220
- Tracks, vias
- 542, 197
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 28 Feb 2018
- Updated
- 27 Jul 2026
Overview
Rfboard is an open-source printed circuit board by candykingdom, from the candykingdom/firefly2 repository on GitHub. It is a 4-layer board of 21 × 63 mm with 67 parts on 53 nets, routed with 542 tracks and 197 vias.
It is built around the CH340X, AP2112K-3.3 and ESD5Z5.0, with the 10118194-0001LF and SRV05-4-P-T7 among its other parts. Its parts include 29 capacitors, 15 resistors, 7 diodes, 6 ICs and 4 connectors. It belongs with the radio and wireless boards and the STM32 boards of this library.
Main components
5CH340X
MSOP-10-20℃~+70℃ 2Mbps 3.3V、5V USB 2.0 USB to serial、USB to Parallel MSOP-10 USB Converters ROHSWCH (Nanjing Qinheng Microelectronics)USB ConvertersAP2112K-3.3
SOT253.3V 600mA CMOS Low Dropout Linear Regulator with EnableDiodes IncorporatedUncategorisedESD5Z5.0
SOD-523-55℃~+150℃ 1 174W 18.6V 50nA 5V 6.2V 80pF 9.4A@8/20us ESD IEC 61000-4-2、IEC 61000-4-4 Unidirectional SOD-523 ESD and Surge Protection (TVS/ESD) ROHSonsemiESD And Surge Protection (TVS/ESD)10118194-0001LF
SMD-30℃~+80℃ 1 100V 5P Black Female Micro-B USB 2.0 SMD USB Connectors ROHSAmphenolUSB ConnectorsSRV05-4-P-T7
SOT-23-612V 1A@8/20us 3.5pF 500W@8/20us 5V 5uA 6V ESD Four channels IEC 61000-4-2、IEC 61000-4-5、IEC 61000-4-4 SOT-23-6 ESD and Surge Protection (TVS/ESD) ROHSPROTEKESD And Surge Protection (TVS/ESD)
README
README.mdFirefly2
Wireless LED control for Burning Man art installations, bikes, and wearables. Devices driving WS2812 strips self-organize over 915 MHz RFM69 radios into a flood mesh with exactly one master, share a network clock via heartbeats, and render effects as pure functions of network time — so every device animates in sync without streaming frames.
New to the project? Start with GETTING_STARTED.md. Working in the code (human or agent)? The mental model lives in docs/index.md and the shared Claude Code/Codex ground rules in CLAUDE.md.
Web simulator (test without hardware)
python3 -m http.server 8642 -d sim
# open http://localhost:8642/A zero-dependency browser simulator of the whole system: every effect and palette on the real device catalog, synced to a scrubbable network clock, with master-mode autoplay and control overrides. Byte-exact against the firmware (enforced by tests: npm test). See docs/simulator.md.
Building firmware
Firmware builds with PlatformIO (pip install platformio). One env per device target:
pio run -e node # SAMD21 rfboard node (node-arm64 on Apple silicon)
pio run -e fancy-node # STM32G030 node
pio run -e controller # STM32G070 handheld controller
pio run -e dmx # ESP32 DMX bridge
pio run -e fancy-node -t upload # flash via ST-Link
pio device monitor # 115200 baudNote: [env:node]'s bossac platform_packages entry is OS-specific — uncomment the right line in platformio.ini for your OS. Full env/pin/flag details: docs/build-and-test.md.
Programming over USB
The fancy-node device can be programmed either using an STLink, or via USB port. To program via USB, you must first install stm32loader using pip (pip install stm32loader). You may also need to pass the port (typically /dev/ttyUSB0), e.g. pio run -e fancy-node-usb -t upload --upload-port /dev/ttyUSB0.
Saving device description in flash
Both node and fancy-node support reading the DeviceDescription from flash. The modes are defined by the DeviceMode enum within DeviceDescription.hpp. They work as follows:
CURRENT_FROM_HEADER: use thecurrentdevice defined inDevices.hppREAD_FROM_FLASH: read the device saved in flash, if present. If not present (determined by the validity ofcheck_value), fall back tocurrent.WRITE_TO_FLASH: writecurrentto flash, and then use it. This will only write the device to flash if it is different, to avoid causing flash wear.
Tests & linting
The platform-independent core (lib/, src/generic/) builds on the host against fakes, with ASan + UBSan on (and fatal). Requires cmake and a GCC/Clang toolchain (on Windows, use WSL or similar):
mkdir -p build && cd build
cmake .. -DBUILD_SIMULATOR=false # true builds the SDL desktop simulator too
make && make test
./smalltests --gtest_filter=RadioStateMachineTest*./lint.sh check # clang-format, Google style — CI enforces this
./lint.sh format # format in place
./ci.sh # exactly what CI runs: cmake + smalltests + largetests
node --test "sim/test/cases/*.test.mjs" # simulator suite, incl. firmware byte-exactness
npm run test:e2e # served UI/API/canvas journeys in Chromium and FirefoxCI (GitHub Actions): host tests, lint, node/fancy-node/controller firmware
builds, the simulator suite, and CodeQL C/C++ security scanning.
Repo layout
| Path | Contents |
|---|---|
lib/, src/generic/ | Platform-independent core: radio protocol, mesh, effects, LED management |
src/arduino/ | Hardware backends (FastLED, RadioHead RFM69) |
src/devices/ | One main per device target (node, fancy-node, controller, dmx) |
test/ | Host GoogleTest suites + FakeNetwork multi-node mesh simulation |
sim/ | Browser simulator (production C++ renderer via committed Wasm, usable without hardware) |
docs/ | Architecture and per-subsystem notes — start at docs/index.md |
hardware/, boards/, bootloader/ | PCB designs, PlatformIO board definitions, bootloaders |
specs/ | Spec-kit feature specs (spec → plan → tasks workflow, see CLAUDE.md) |
For agents & contributors
- CLAUDE.md — the canonical guidance for Claude Code and Codex, including build commands, architecture, and the invariants you must not break. Codex reaches the same file through
AGENTS.md; shared skills remain canonical under.claude/skills/and are exposed to Codex through.agents/skills/. - docs/ — per-subsystem research notes (radio/network, LED/effects, devices, build/test, hardware). Update them when you change documented behavior.
- Substantial features go through the spec-kit workflow (
speckit-specify→plan→tasks→implement; use/in Claude Code or$in Codex); specs live inspecs/.
Parts
67| Qty | Value | Footprint | References |
|---|---|---|---|
| 16 | 100nF | Capacitor_SMD:C_0402_1005Metric | C1, C2, C3, C4, C5, C8, C11, C13, C16, C18, C21, C22, C23, C25, C28, C29 |
| 6 | 10uF | Capacitor_SMD:C_0603_1608Metric | C6, C9, C12, C14, C17, C20 |
| 5 | ESD5Z5.0 | Diode_SMD:D_SOD-523 | D1, D4, D5, D6, D7 |
| 4 | 10k | Resistor_SMD:R_0402_1005Metric | R9, R10, R13, R15 |
| 4 | 1k | Resistor_SMD:R_0402_1005Metric | R2, R4, R7, R8 |
| 4 | 47uF | Capacitor_SMD:C_1206_3216Metric | C10, C15, C19, C26 |
| 3 | SW_Push | Homebrew:SW_TACTILE_5.1MM_TS-1187A-C-D-B | SW1, SW2, SW3 |
| 2 | 0 | Inductor_SMD:L_0402_1005Metric_Pad0.77x0.64mm_HandSolder | L1, L2 |
| 2 | 470 | Resistor_SMD:R_0402_1005Metric | R5, R6 |
| 2 | 5k1 | Resistor_SMD:R_0402_1005Metric | R12, R14 |
| 1 | 0R | Capacitor_SMD:C_0402_1005Metric_Pad0.74x0.62mm_HandSolder | C7 |
| 1 | 10118194-0001LF | Homebrew:HRO_TYPE-C-31-M-12 | J1 |
| 1 | 15k | Resistor_SMD:R_0402_1005Metric | R11 |
| 1 | 220uF | Capacitor_SMD:CP_Elec_6.3x5.8 | C27 |
| 1 | 22k | Resistor_SMD:R_0402_1005Metric | R3 |
| 1 | 2337019-1 | Homebrew:CONN_2337019-1 | J3 |
| 1 | 47pF | Capacitor_SMD:C_0402_1005Metric | C24 |
| 1 | 4k7 | Resistor_SMD:R_0402_1005Metric | R1 |
| 1 | AP2112K-3.3 | Package_TO_SOT_SMD:SOT-23-5 | U5 |
| 1 | CH340X | Package_SO:MSOP-10_3x3mm_P0.5mm | U3 |
| 1 | CONN_01X03 | Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical | P2 |
| 1 | Conn_01x02 | Homebrew:PinHeader_1x02_P2.54mm_Vertical_NoPlastic | J4 |
| 1 | HX 1210-C06 | Homebrew:SMD-2P_L2.9-W2.4_C9900033648 | U6 |
| 1 | RED | LED_SMD:LED_0603_1608Metric | D2 |
| 1 | RFM69HCW | Homebrew:RFM69HCW-minimalpads | U2 |
| 1 | SRV05-4-P-T7 | Package_TO_SOT_SMD:SOT-23-6 | D3 |
| 1 | STM32G070KBTx | Package_QFP:LQFP-32_7x7mm_P0.8mm | U1 |
| 1 | STRAIN_RELIEF | Homebrew:3_pin_2.54mm_pitch_strain_relief | H3 |
| 1 | XL-0807RGBC-WS2812B | Homebrew:LED-SMD_4P-L2.0-W1.8_CY-0807 | U4 |
Questions
How big is the Rfboard PCB?
It measures 21 × 63 mm and has 4 copper layers, 1.61 mm thick.
What parts does the Rfboard use?
67 parts, built around the CH340X, AP2112K-3.3, ESD5Z5.0 and 10118194-0001LF. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Rfboard KiCad files?
From the candykingdom/firefly2 repository on GitHub, at the commit this page was made from: the board is hardware/rfboard/rfboard.kicad_pcb and its schematic hardware/controller/controller.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Rfboard design in my own project?
Its repository states no licence, so its author keeps all rights: ask candykingdom before reusing the design.
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