Hardware
PUCK RACER is a fully open-source hardware project. Each puck is built around an ESP32-C3 microcontroller, a WS2812B LED ring and a rechargeable 18650 battery. The PCB was designed specifically for this project.
Bill of Materials (BoM)
All parts for 8 pucks + 1 coordinator. Quantities shown are minimum order amounts — some parts include spares.
| Component | Qty | Link | |
|---|---|---|---|
| Puck (ESP32-C3) — 8 per set | |||
 |
ESP32-C3 SuperMini Warning: The pinout must match exactly, otherwise the PCB won't fit! The linked C3 is compatible. |
8 | AliExpress |
 |
WS2812B 35 LED Ring | 8 | AliExpress |
 |
Arcade Button (60 mm) | 8 | AliExpress |
 |
18650 Li-Ion Battery Example battery — we recommend using a brand-name cell (e.g. Samsung, Sony/Murata, LG). Don't skimp on batteries! Cheap Li-Ion cells can catch fire. |
8 | AliExpress |
 |
TP4056 Charge Board (USB-C) | 10 | AliExpress |
 |
5V 3A Step-Up Converter | 8 | AliExpress |
 |
Piezo Buzzer (passive) | 10 | AliExpress |
 |
Electrolytic Capacitor (1000µF) | 10 | AliExpress |
 |
On/Off Switch | 10 | AliExpress |
| Coordinator (ESP32-S3) | |||
 |
ESP32-S3 N16R8 DevKit | 1 | AliExpress |
| Optional Accessories | |||
 |
JST Connectors (Cables) | 25 | AliExpress |
 |
USB-C Adapter | 10 | AliExpress |
 |
PETG Filament (3D-printed enclosure) | 2 kg | AliExpress |
* These are affiliate links. Purchasing through these links supports the PUCK RACER project — at no extra cost to you.
Total cost for a set of 8 pucks + 1 coordinator is approximately €180–200 (excluding PCBs and 3D printing).
Battery Safety Notice: The firmware includes temperature monitoring (NTC sensor) and the TP4056 charge board provides over-charge/deep-discharge protection — however, cheap no-name Li-Ion cells are a real fire hazard. Only use brand-name batteries (Samsung, Sony/Murata, LG, Molicel) with built-in protection PCB. Don't skimp on the battery!
PCB — Order Circuit Boards
The PUCK RACER board is a custom PCB design (KiCad). You can upload the Gerber files directly to a PCB manufacturer and have the boards fabricated.
In addition to connectors for the ESP32-C3, LED ring, button and buzzer, the board includes an NTC temperature sensor (10kΩ, Beta 3950) for overheat detection and a voltage divider for battery monitoring, allowing the firmware to track battery level in real time and automatically shut down at critical charge levels.
Open-Source Hardware — The PCB designs are licensed under the CERN Open Hardware Licence v2 – Permissive (CERN-OHL-P-2.0). You are free to use, modify, reproduce and even sell the board. This is a developer board — all warranties and liability are disclaimed. Use at your own risk.
Gerber & Production Files
Download the ZIP file and upload it directly to your PCB manufacturer. Individual files are provided for manual inspection.
How to Order the PCB
The most popular PCB manufacturers for hobbyists are JLCPCB and PCBWay. Both accept Gerber files and ship worldwide. Here's how:
- Go to jlcpcb.com or pcbway.com and create an account.
- Click "Order Now" or "Quick Order PCB".
- Upload the
PBC.ziporGerber.zipfile. Board dimensions and layers are detected automatically. - Set the quantity (min. 5 boards, recommended: 10 for 8 pucks + spares).
- Choose color and thickness (default: green, 1.6 mm — both work fine).
- Optional (JLCPCB): Upload the BOM and Pick&Place files to order SMD assembly (SMT Assembly) along with the boards.
- Place the order — delivery takes approx. 7–14 days.
Note: The boards themselves are cheap (5 pcs often under $2), but shipping costs can be relatively high. From experience: with 30 boards the cost comes to about €6 per board including shipping. Ordering a larger batch helps reduce the per-unit shipping cost.
Assembly & Soldering Guide
Step-by-step videos on soldering, assembly and flashing the pucks. From bare PCB to finished puck.