Macropad

XIAO V1 -- Macropad

A custom 3×4 macropad with a rotary encoder, built around an RP2040 (More specifically the Seeeduino XIAO RP2040). Includes full KiCad hardware design and PlatformIO prototyping firmware.

Overview

• Layout: 3×4 key matrix (12 keys) + 1 rotary encoder (with push switch)
• MCU: XIAO RP2040
• Hardware: Custom PCB designed in KiCad, diode-per-switch matrix
• Firmware: Tested prototype an Arduino framework via PlatformIO, flashed CircuitPython for full functionality

Status

This project was my first ever attempt at designing a PCB from scratch. After independently teaching myself some of the fundamentals of KiCAD and how to solder electronics, I already began designing a slightly more sophisticated prototype to further develop these skills. (A new repo featuring that project will be uploaded soon!).

Still prototyping a 3D printed case after a couple of iterations with fitment issues.

The firmware currently included in this repo contains the prototyping firmware. key matrix encoder and prints activity over Serial (115200 baud). This is intended to verify the board (solder joints, diode orientation, encoder wiring) before real key-mapping firmware is written.

Repository Structure

.
├── firmware/           PlatformIO project (Arduino framework)
│   ├── src/main.cpp    
│   └── platformio.ini 
├── hardware/           KiCad project
│   ├── macropad.kicad_pro / .kicad_sch / .kicad_pcb
│   ├── macropad.dsn    
│   └── gerbers/        
└── docs/               Additional documentation / images
│   └── prototype.png        

Hardware

Designed in KiCad. Key matrix uses one diode per switch (standard anti-ghosting matrix). GPIO Pin mapping:

Acknowledgments

These two libraries helped tremendously in the design process:

https://github.com/ebastler/marbastlib

https://github.com/zykrah/kicad-kle-placer

I'd also like to acknowledge these projects with helped inspire my own:

https://github.com/sb-ocr/ocreeb-12

https://github.com/bytesizedengineering/macropad/