2 layers304.4 × 98.8 mm Grain, the printed circuit board in 3D

Grain

TReK GRAIN Specification

Size: 304.4 × 98.8 mm
Copper layers: 2
Thickness: 1.6 mm
Parts: 204
Nets: 157
Pads: 832
Tracks, vias: 2,552, 245
Routed: Yes
KiCad: KiCad 9.0 (file 20241229)
Created: 10 Apr 2026
Updated: 10 Apr 2026

Overview

Grain is an open-source printed circuit board by digitarhythm, from the digitarhythm/grain repository on GitHub, published under the MIT licence. It is a 2-layer board of 304.4 × 98.8 mm with 204 parts on 157 nets, routed with 2,552 tracks and 245 vias.

It is built around the RP2040-ZERO and SK6812MINI-E. Its parts include 69 diodes, 68 switches, 65 inductors and 1 IC. It belongs with the RP2040 boards of this library.

Main components

README

README.md

TReK GRAIN

TReK GRAIN KiCAD Project

Firmware repository

Parts

204

Qty	Value	Footprint	References
69	D	kbd_Parts:Diode_SMD	D0, D1, D2, D10, D11, D12, D13, D14, D15, D16, D17, D18, D19, D20, D21, D22 +53
65	SK6812MINI	kbd_Parts:LED_SK6812MINI-E_BL	L1, L2, L10, L11, L12, L13, L14, L15, L16, L17, L18, L19, L20, L21, L22, L23 +49
65	SW_PUSH	kbd_SW:Choc_v2_Hotswap_1u	SW1, SW2, SW10, SW11, SW12, SW13, SW14, SW15, SW16, SW17, SW18, SW19, SW20, SW21, SW22, SW23 +49
3	RotaryEncoder_Switch	kbd_Parts:RotaryEncoder_EC12E	SW4, SW53, SW64
1	LOGO	LOGO	G***
1	rp2040-zero	RP2040:rp2040-zero_rev(THonly)	U1

Questions

How big is the Grain PCB?

It measures 304.4 × 98.8 mm and has 2 copper layers, 1.6 mm thick.

What parts does the Grain use?

204 parts, built around the RP2040-ZERO and SK6812MINI-E. 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 Grain KiCad files?

From the digitarhythm/grain repository on GitHub, at the commit this page was made from: the board is pcb/grain.kicad_pcb and its schematic pcb/grain.kicad_sch. PCBKit opens the board in the browser, with nothing to install.

Can I use the Grain design in my own project?

Its repository publishes it under the MIT licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).

Category and platform

RP2040

Project files

Show this board on your page

A live frame, for any web page

<iframe src="https://pcbkit.io/embed/boards/digitarhythm-grain" title="Grain in PCBKit" width="100%" height="480" style="border:0;border-radius:12px" allow="fullscreen" loading="lazy"></iframe>

A picture

<img src="https://pcbkit.io/embed/boards/digitarhythm-grain.jpg" alt="Grain" width="1200" height="900">

A picture that opens the board, for a README

[![Grain](https://pcbkit.io/embed/boards/digitarhythm-grain.jpg?size=s)](https://pcbkit.io/boards/digitarhythm-grain)

Source

Repository: digitarhythm/grain
Board file: pcb/grain.kicad_pcb
Commit: 09e50a0
Licence: MIT

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