Cornelius

foostan·corneliuskbd·pcbs/v2/hotswap/cornelius.kicad_pcb

About the Cornelius PCB

Cornelius is an open source RP2040/RP2350 PCB design by foostan, published on GitHub under the CC-BY-NC-4.0 license. It is a 2-layer board measuring 271.3 × 120 mm, with 124 components from 15 distinct parts.

Its main chip is the RP2040, from the RP2040/RP2350 family. Other key parts include the NCP1117-3.3_SOT223 and W25Q128JVSIQ. By type, the board carries 48 diodes, 16 capacitors, 5 resistors, 3 ICs, 1 crystal and 1 connector.

It belongs with the keyboards designs in this gallery.

From the project

The public branch for the cornelius keyboard

There are several version. - v1: Cornelius, geekhack - v2: Cornelius Low-profile, youtube

This is the public repository for Cornelius keyboard series. Cornelius Keyboard by foostan is licensed under CC BY-NC-SA 4.0

Cornelius, from the project README — From the project README

Main components on the Cornelius

RP2040 NCP1117-3.3_SOT223 W25Q128JVSIQ

Cornelius bill of materials (BOM)

124 components, 15 distinct parts — part numbers from the project's BOM.

Qty	Part	Footprint	Refs
1	RP2040	QFN-56-1EP_7x7mm_P0.4mm_EP3.2x3.2mm	U1
1	NCP1117-3.3_SOT223	SOT-223-3_TabPin2	U2
1	W25Q128JVSIQ	SOIC-8_5.23x5.23mm_P1.27mm	U3
1	C91749 12MHz 18pF	Crystal_SMD_3225-4Pin_3.2x2.5mm	Y1
1	78171-0004	Pico-EZmate_PCB_Header	J2
2	TS-1088R-02026	TS-1088R-02026	BOOT_SW1, RESET_SW1
48	SW_Push	keyswitch_choc12_hotswap_1u	MX1, MX2, MX3, MX4, MX5, MX6, MX7, MX8 +40
48	SOD-523	D_SOD-523	D1, D2, D3, D4, D5, D6, D7, D8 +40
9	100N 100n	C_0402_1005Metric	C1, C2, C3, C4, C5, C6, C7, C8 +1
3	1u	C_0402_1005Metric	C10, C11, C14
2	27P 27p	C_0402_1005Metric	C12, C13
2	10U 10u	C_0402_1005Metric	C15, C16
2	27	R_0402_1005Metric	R1, R2
2	1k	R_0402_1005Metric	R3, R5
1	10K 10k	R_0402_1005Metric	R4

Cornelius design files

The KiCad project lives in the foostan/corneliuskbd repository on GitHub; these links point at the commit this page was built from.

Cornelius: common questions

What microcontroller does the Cornelius use?

The Cornelius is built around the RP2040, from the RP2040/RP2350 family.

How big is the Cornelius PCB?

The Cornelius measures 271.3 × 120 mm, has 2 copper layers and is 1.6 mm thick.

How many components are on the Cornelius?

124 components, from 15 distinct parts, with part numbers taken from the project's own BOM. The full bill of materials is listed on this page.

Where can I download the Cornelius design files?

From the foostan/corneliuskbd repository on GitHub, which has the KiCad layout, the schematic and the BOM; the links under Design files point to each one.

Can I use the Cornelius design in my own project?

It is published under CC-BY-NC-4.0, which limits how it may be reused; read the license before building on it.

Can I test firmware for the Cornelius without the hardware?

Yes. HardLabs builds a simulation of the board from its netlist and BOM, so you can run and debug RP2040/RP2350 firmware against it before you order a PCB.