4 layers234 × 84 mm
Main panel
google/mozc-devices
Circuit diagrams and firmware source code for Gboard DIY keyboards
234 parts3kApache-2.0
2 layers93.3 × 94.2 mm
RatPad
MrDiamondDog/RatPadMy own personal (rat-themed) hackpad! Featuring a decorative 4x4 RGB LED matrix, an informational screen, rats, and a ton of keys to control anything with!
- Size
- 93.3 × 94.2 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 45
- Nets
- 42
- Pads
- 183
- Tracks, vias
- 293, 18
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 29 Dec 2025
- Updated
- 30 Dec 2025
Overview
RatPad is an open-source printed circuit board by MrDiamondDog, from the MrDiamondDog/RatPad repository on GitHub. It is a 2-layer board of 93.3 × 94.2 mm with 45 parts on 42 nets, routed with 293 tracks and 18 vias.
It is built around the SK6812MINI-E. Its parts include 28 diodes, 12 switches and 1 IC. It belongs with the lEDs and displays boards and the RP2040 boards of this library.
Main components
1README
README.mdRatPad
My own personal (rat-themed) hackpad! Featuring a decorative 4x4 RGB LED matrix, an informational screen, rats, and a ton of keys to control anything with!
The goal of this project is to learn! I have been wanting experience with PCBs, Fusion, and soldering for a while and this is a good all-in-one project to get that experience at no cost to me.
Part of Hack Club's Blueprint YSWS.
Features
- 12 Keys.
- 4x4 RGB LED Matrix.
- 0.91in OLED display.
- Multiple layers, programmable keys, etc.
- LED Matrix for cool decoration. No practical purpose.
- A rat drawn on the silkscreen of the PCB.
- Black + Blue theme
- KMK Firmware
Todo
- Schematic
- Routing PCB
- Case Design
- Basic Firmware
- Get Physical Items
- Solder PCB
- Finished Build!
PCB
Here's the schematic and routed PCB! There's a lot of stuff on the silkscreen for fun and the LEDs and keys are both routed in matrices to save on GPIOs! In fact, I have one GPIO available still!
I decided to do chamfered edges on all the corners, with a big one in the lower left since I had extra space and figured it would look nice.
I've also included M3 screw holes, I don't think I'll be using them though.
I definitely should have added a ground plane, but it should be fine.
Case
Here's all the images of the case! There's a window on the left of the lid to see all the interesting electronics, silkscreen, and LED matrix, a hole for the OLED, and all the holes for the keys.
The chamfered edges from the PCB are reflected on the case as well.
The lid is held on with 4 M3 screws.
I would love to add some acrylic to the window and/or oled, but I don't have access to a laser cutter or any acrylic in the first place.
BOM
| Item | Quantity |
|---|---|
| PCB | 1 |
| Through-Hole Seeed XIAO RP2040 | 1 |
| MX Style Switches | 12 |
| DSA Keycaps | 12 |
| Through-Hole IN4148 Diodes | 12 |
| 0.91in OLED I2C Display | 1 |
| SK6812 MINI-E LEDs | 16 |
| M3x16mm Screws | 4 |
| 3d Printed Parts (case + lid) | 2 |
Parts
45| Qty | Value | Footprint | References |
|---|---|---|---|
| 16 | SK6812MINI | LED_SMD:LED_SK6812MINI_PLCC4_3.5x3.5mm_P1.75mm | D1, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11, D12, D13, D14, D15, D16 |
| 12 | 1N4148 | Diode_THT:D_DO-35_SOD27_P7.62mm_Horizontal | D17, D18, D19, D20, D21, D22, D23, D24, D25, D26, D27, D28 |
| 12 | SW_Push | Button_Switch_Keyboard:SW_Cherry_MX_1.00u_PCB | SW1, SW2, SW3, SW4, SW5, SW6, SW7, SW8, SW9, SW10, SW11, SW12 |
| 1 | XIAO-RP2040-DIP | Seeed Studio XIAO Series Library:XIAO-RP2040-DIP | U1 |
| 1 | ~ | Other:SSD1306-0.91-OLED-4pin-128x32 | OLED1 |
The 42 most common of 45 parts.
Questions
How big is the RatPad PCB?
It measures 93.3 × 94.2 mm and has 2 copper layers, 1.6 mm thick.
What parts does the RatPad use?
45 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 RatPad KiCad files?
From the MrDiamondDog/RatPad repository on GitHub, at the commit this page was made from: the board is pcb/RatPad.kicad_pcb and its schematic pcb/RatPad.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the RatPad design in my own project?
Its repository states no licence, so its author keeps all rights: ask MrDiamondDog before reusing the design.
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