4 layers234 × 84 mm
Main panel
google/mozc-devices
Circuit diagrams and firmware source code for Gboard DIY keyboards
234 parts3kApache-2.0
2 layers100 × 90 mm
Hackpad
agilfor/maxpadMaxpad is a 12 key macropad with two rotary encoders, an OLED display, and 20 LEDs. It runs on QMK firmware.
- Size
- 100 × 90 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 48
- Nets
- 46
- Pads
- 196
- Tracks, vias
- 539, 43
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 28 Aug 2026
- Updated
- 29 Aug 2026
Overview
Hackpad is an open-source printed circuit board by agilfor, from the agilfor/maxpad repository on GitHub. It is a 2-layer board of 100 × 90 mm with 48 parts on 46 nets, routed with 539 tracks and 43 vias.
It is built around the SK6812MINI-E. Its parts include 20 inductors, 14 switches, 12 diodes and 2 ICs. It belongs with the keyboards and input boards of this library.
Main components
1README
README.mdMaxpad
Maxpad is a 12 key macropad with two rotary encoders, an OLED display, and 20 LEDs. It runs on QMK firmware.
Features
- OLED Display
- Two customizeable rotary encoders
- 20 SK6812-MINI-E LEDs as indicators for the rotary encoders
- 12 keys
- VIA support (WIP)
CAD Model (v1)
The idea is for the PCB to slide into the main body in a printed groove. The body can be locked with a second 3D-printed piece, and two M3x5x4mm heat insets and two M3x16mm screws.
The current design is simply to hold the PCB, but doesn't yet incorporate a keyplate or any real coverings. This may be added in a v2 of the CAD design, but for now the priority is getting the current setup to be functional. The design was made in Blender.
PCB
My PCB was made in KiCad. It doesn't incorporate a lot of fancy silkscreen images (although I would've liked to) as I needed the space to fit components within the size limit.
This is my current schematic. It uses charlieplexing to wire the keys (which is how I fit in so many with only 4 pins). The downside is it means I need to write more firmware to make it work. In hindsight, I should really have used net labels when making this, but it was my first time and I didn't know ¯\_(ツ)_/¯
This is my PCB. The routing was difficult mostly cuz there are so many components and I had a size limit. It was fun to make though :)
Firmware Overview
The maxpad uses QMK firmware for everything. Currently it should support 12 customizeable keys and 2 customizeable rotary encoders.
Support still needs to be added for the OLED and LEDs. This is a WIP and will be done post assembly.
There will probably be more changes as well to the firmware after all this, but that remains TBD.
BOM
- 1x Seeed XIAO RP2040
- 12x Cherry MX switches
- 12x white blank DSA keycaps
- 1x 0.91 inch OLED display
- 2x EC11 rotary encoders
- 20x through-hole 1N4148 Diodes
- 20x SK6812 MINI-E LEDs
- 2x M3x16mm screws
- 2x M3x5x4mm heat insets
Parts
48| Qty | Value | Footprint | References |
|---|---|---|---|
| 20 | SK6812MINI-E | hackpad:SK6812MINI-E_fixed | L0, L1, L2, L3, L4, L5, L10, L11, L12, L13, L14, L15, L16, L17, L18, L19 +4 |
| 12 | 1N4148 | Diode_THT:D_DO-35_SOD27_P7.62mm_Horizontal | D0, D1, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11 |
| 12 | SW_Push | Button_Switch_Keyboard:SW_Cherry_MX_1.00u_PCB | SW0, SW1, SW2, SW3, SW4, SW5, SW6, SW7, SW8, SW9, SW10, SW11 |
| 2 | RotaryEncoder_Switch | hackpad:RotaryEncoder_Alps_EC11E-Switch_Vertical_H20mm | SW12, SW13 |
| 1 | ER_OLEDM0.91_1x-I2C | Display:ER_OLEDM0.91_1x-I2C | U2 |
| 1 | MOUDLE-SEEEDUINO-XIAO | hackpad:XIAO-Generic-Hybrid-14P-2.54-21X17.8MM | U1 |
Questions
How big is the Hackpad PCB?
It measures 100 × 90 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Hackpad use?
48 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 Hackpad KiCad files?
From the agilfor/maxpad repository on GitHub, at the commit this page was made from: the board is src/PCB/hackpad.kicad_pcb and its schematic src/PCB/hackpad.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Hackpad design in my own project?
Its repository states no licence, so its author keeps all rights: ask agilfor before reusing the design.
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