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2 layers285 × 94.6 mmMain3, the printed circuit board in 3D

YUIOP: Etude of designing keyboards

Size
285 × 94.6 mm
Copper layers
2
Thickness
1.6 mm
Parts
207
Nets
161
Pads
1,062
Tracks, vias
1,908, 57
Pours
2
Routed
Yes
KiCad
KiCad 5 (file 20171130)
Created
10 Jan 2021
Updated
31 Jan 2026

Overview

Main3 is an open-source printed circuit board by koron, from the koron/yuiop repository on GitHub, published under the MIT licence. It is a 2-layer board of 285 × 94.6 mm with 207 parts on 161 nets, routed with 1,908 tracks and 57 vias.

It is built around the 1N4148W, WS2812C-2020-V1 and BSS138. Its parts include 116 diodes, 4 capacitors, 4 connectors, 2 resistors and 1 IC. It belongs with the keyboards and input boards of this library.

Main components

3

README

README.md

YUIOP Keyboard series

YUIOP keyboards are experimental original keyboards designed by KoRoN.

Sub Projects

Keyboards in this project are:

  • yuiop27/ - separate keyboard prototype.

    27 keys for one hand. single left hand.

  • yuiop54/main - signle board keyboard prototype.

    combined right and left-hand boards of yuiop27. PCB dimension is 285.00mm x 94.60mm (GH60 compatible form factor without screw holes).

  • yuiop54/main2 - researching version of yuiop54.

    multi-sheets schematic. fix layout for auto routing. introduce GND cupper fill.

    • rev.B - trial to make compatible with GH60 (include screw holes).

      use popular keycaps size. tring 128x64 dots OLED.

    • rev.C - key sizes revised version.

      consider just layout. use 1u footprint for keys of little fingers. compact form factor size, 267.00mm x 95.00mm (drop compatibility with GH60). change the origin to center of PCB. use 2u for R5 center key. use Edge.Cuts to represents screw holes. OLED is 128x32 dots.

    • rev.D - narrowwer version of rev.C

      consider just layout. the dimension is 262.0mm x 95.00mm reduce margins between F and G keys, and H and J keys.

    • rev.E - a variation of rev.C

      the dimension is 267.00mm x 95.00mm (same with rev.C, not rev.D) make keys on F's row be able to use 1.25u keycap.

  • yuiop47/ - Single board keyborard with 47 keys.

    Shrink from yuiop54. PCB dimension is 214.00mm x 94.00mm

  • yuiop60hh/main - HHKB clone trial

    • main2 - HHKB clone trial #2
    • main3
    • main4
    • main5 - Practicing version
    • main5b - USB Type-C receptacle version of main5
  • yuiop50d/ - Small footprint, dense 50 keys keyboard.

    1u is 16mm, using small keycaps. Standard row staggered layout. Support Pro Micro and RapsberryPi Pico as MCU. PCB dimension is 182.00mm x 103.50mm

  • yuiop63hhs/ - Split HHKB layout minimal keyboard.

    No LED nor OLED, Just 63 (29+34) keys. PCB dimension 319.00mm x 95.00mm

    • Left 152.50mm x 95.00mm
    • Right 162.00mm x 95.00mm
  • yuiop22rs/ - 22 keys + rotary switch macropad.

    With OLED, without LED. PCB dimension 95.25mm x 95.25mm

  • contorller/ - Keyboard controler using ATmega32U4 which replacing Pro Micro.

  • yuiopPM/ - Pro Micro compatible but minimal for only keyboard, PCB

  • yuiopPM2/ - Revised version of yuiopPM. It was shelved unfinished.

  • yuiop60hh/main3 - HHKB layout, compatible with popular 60% cases.

    Problems on positions of screw hole or so. Not built.

  • yuiop60hh/main4 - HHKB layout, compatible with popular 60% cases.

    YUIOP60HH series revision 4. Implemented with MPU ATmega32U4 (not Pro Micro)

  • yuiop31rs/ - 31 keys + rotary switch macropad.

    With 31 LEDs (WB2812C-2020). Its hole is too small to be chaged extra on production.

  • yuiop60s/ - split keyboard prototype

  • yuiop60pi/ - PGA2040 (RP2040) base HHKB layout semi-compatible keyboard.

  • yuiop2040/ - Original RP2040 control board.

  • yuiop2040C/ "Compact" model of yuiop2040. Abandoned.

  • yuiop32dm/ - Experimental keyboard for Duplic Matrix

  • yuiopPD/ - Pointing device using the trackball module of Keyball series.

  • rp2040-controller/ - Reusable circuit diagram for controller using RP2040

Parts

207
QtyValueFootprintReferences
601N4148Wyuiop:D_SOD-123D1, D2, D10, D11, D12, D13, D14, D15, D16, D17, D18, D19, D20, D21, D22, D23 +44
60MX_HOTSWAPyuiop:Cherry_MX_Hotswap_1.0u_v2KSW1, KSW2, KSW10, KSW11, KSW12, KSW13, KSW14, KSW15, KSW16, KSW17, KSW18, KSW19, KSW20, KSW21, KSW22, KSW23 +44
56WS2812C-2020yuiop:LED_WS2812C-2020_BackMount_v2LED1, LED2, LED10, LED11, LED12, LED13, LED14, LED15, LED16, LED17, LED18, LED19, LED20, LED21, LED22, LED23 +40
6Hole_2.2_4yuiop:Hole_2.2_4HOLE7, HOLE8, HOLE9, HOLE10, HOLE11, HOLE12
410uCapacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolderC1, C2, C3, C4
3Hole_5x2.3_6yuiop:Hole_5x2.5_7HOLE1, HOLE2, HOLE4
210KResistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolderR1, R2
2Cherry_MX_Stabilizeryuiop:Cherry_MX_StabilizerSTB1, STB3
2Hole_7x2.5yuiop:Hole_7x2.5_10x5HOLE5, HOLE6
1BSS138Package_TO_SOT_SMD:SOT-23Q1
1Cherry_MX_Stabilizer_6.25uyuiop:Cherry_MX_Stabilizer_6.25uSTB2
1DEBUGConnector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_VerticalJ3
1D_SchottkyDiode_SMD:D_SOD-123DS1
1FuseFuse:Fuse_1206_3216Metric_Pad1.42x1.75mm_HandSolderF1
1Hole_2.3yuiop:Hole_5x2.5_7HOLE3
1LOGOproject:QR_READMEG1
1PGA2040yuiop:PGA2040U1
1RESETButton_Switch_SMD:SW_Push_1P1T_NO_6x6mm_H9.5mmRSW1
1UARTConnector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_VerticalJ4
1USB_B_MicroConnector_USB:USB_Micro-B_Amphenol_10103594-0001LF_HorizontalJ1
1USB_MONConnector_PinHeader_2.54mm:PinHeader_1x04_P2.54mm_VerticalJ2

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Questions

How big is the Main3 PCB?

It measures 285 × 94.6 mm and has 2 copper layers, 1.6 mm thick.

What parts does the Main3 use?

207 parts, built around the 1N4148W, WS2812C-2020-V1 and BSS138. 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 Main3 KiCad files?

From the koron/yuiop repository on GitHub, at the commit this page was made from: the board is yuiop60pi/main3/main3.kicad_pcb. PCBKit opens the board in the browser, with nothing to install.

Can I use the Main3 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).