4 layers234 × 84 mm
Main panel
google/mozc-devices
Circuit diagrams and firmware source code for Gboard DIY keyboards
234 parts3kApache-2.0
2 layers280.1 × 81.3 mm
Td40
NLTD2010/td40A 40% hotswappable keyboard, with a knob, display and RGB per-key. Made with love from me
- Size
- 280.1 × 81.3 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 143
- Nets
- 118
- Pads
- 647
- Tracks, vias
- 1,127, 112
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 16 Aug 2025
- Updated
- 2 Jun 2026
Overview
Td40 is an open-source printed circuit board by NLTD2010, from the NLTD2010/td40 repository on GitHub, published under the MIT licence. It is a 2-layer board of 280.1 × 81.3 mm with 143 parts on 118 nets, routed with 1,127 tracks and 112 vias.
It is built around the SK6812MINI-E. Its parts include 47 switches, 46 diodes, 45 inductors and 1 IC. It belongs with the lEDs and displays boards and the nRF52 and nRF5x boards of this library.
Main components
1README
README.mdTD40
TD40 is a compact 40% mechanical keyboard designed for efficiency and portability.
It features hot-swappable switches, a rotary knob, an OLED display, wireless connectivity, and per-key RGB lighting.
🖼️ Preview
| TD40 (Back) | PCB |
|---|---|
 |  |
✨ Features
- Clean PCB design with SMD soldering
- Nice!Nano v2 microcontroller – USB-C & Bluetooth compatible
- Rotary encoder + knob
- 0.91" OLED screen
- Per-key RGB lighting
- Hot-swappable switches
- Open & visible components (Plaid / Romac style)
- Simple, flexible case options
⌨️ Layout
📦 Bill of Materials
| # | Item | Qty |
|---|---|---|
| 1 | PCB | 1 |
| 2 | FR4 plate | 1 |
| 3 | Mica case | 1 |
| 4 | Controller (Nice!Nano v2) | 1 |
| 5 | Switches (5-pin MX footprint) | 45 |
| 6 | Kailh hotswap socket | 45 |
| 7 | Diodes | 46 |
| 8 | Rotary encoder & knob | 1 |
| 9 | 0.91" OLED screen | 1 |
💡 Tip: Check out the repository for firmware, build guide, and more!
Parts
143| Qty | Value | Footprint | References |
|---|---|---|---|
| 45 | SK6812MINI | crone:YS-SK6812MINI-E | L1, L2, L10, L11, L12, L13, L14, L15, L16, L17, L18, L19, L20, L21, L22, L23 +29 |
| 45 | ~ | crone:D_SOD-123 | D1, D2, D10, D11, D12, D13, D14, D15, D16, D17, D18, D19, D20, D21, D22, D23 +29 |
| 36 | KEYSW | crone:MX-Hotswap-1U | K1, K2, K10, K11, K14, K15, K16, K17, K18, K19, K20, K21, K22, K23, K26, K27 +20 |
| 4 | KEYSW | crone:MX-Hotswap-1.25U | K13, K37, K38, K39 |
| 2 | KEYSW | crone:MX-Hotswap-1.75U | K12, K25 |
| 1 | Battery_Cell | crone:JST_PH_S2B-PH-K_1x02_P2.00mm_Horizontal_flipped | BT1 |
| 1 | D | crone:D_SOD-123 | D46 |
| 1 | KEYSW | crone:MX-Hotswap-2.75U-ReversedStabilizers | K41 |
| 1 | KEYSW | crone:MX-Hotswap-2.25U-ReversedStabilizers | K40 |
| 1 | KEYSW | crone:MX-Hotswap-1.5U | K24 |
| 1 | LOGO | LOGO | G*** |
| 1 | RotaryEncoder_Switch | keebio:RotaryEncoder_Alps_EC11E-Switch_Vertical_H20mm | SW1 |
| 1 | SW23 | crone:switch-MSK-12C02-smd | SW23 |
| 1 | SW_PUSH | crone:ResetSW | RSW1 |
| 1 | nice!view | crone:nice_view | Display1 |
| 1 | nice_nano | crone:ProMicro | U1 |
Questions
How big is the Td40 PCB?
It measures 280.1 × 81.3 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Td40 use?
143 parts, built around the 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 Td40 KiCad files?
From the NLTD2010/td40 repository on GitHub, at the commit this page was made from: the board is PCB/td!40.kicad_pcb and its schematic PCB/td!40.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Td40 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).
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