AZB-12 AN-13 · macropad.notazizelse.xyz

← AZB-12 data sheet

Application note AN-13 · U13

Macropad

2026 · macropad.notazizelse.xyz
ABSTRACT

A small programmable keyboard I made for Hack Club's macropad program. It runs on a Seeed XIAO RP2040 with KMK, a Python-based keyboard firmware, and has an OLED and RGB LEDs.

Macropad PCB layout in KiCad
Figure 1.The PCB layout, from the repo.

1From the README

A custom macro pad featuring 16 mechanical switches, OLED display, and RGB LEDs. Built with the Seeed XIAO RP2040 microcontroller and KMK firmware for a compact, programmable keyboard solution.

Features

  • 4 Cherry MX Switches: Tactile mechanical switches for responsive key presses
  • 0.96" OLED Display: SH1106 I2C display for status or custom graphics
  • RGB LED Matrix: WS2812B LEDs for visual feedback
  • Compact Design: Fits within 200x200x100mm enclosure
  • KMK Firmware: Python-based firmware for easy customization

Images

Schematic

Schematic

PCB Layout

PCB

Case Assembly

Bill of Materials (BOM)

Part Quantity Description Supplier
Seeed XIAO RP2040 1 RP2040 microcontroller board Seeed Studio
Cherry MX Switch 16 Mechanical keyboard switches Cherry
DSA Keycaps 16 Cherry MX compatible keycaps Keycaps Direct
0.96" OLED Display 1 SH1106 128x64 I2C OLED AliExpress
SK6812 MINI-E LED 12 RGB LEDs AliExpress
Custom PCB 1 2-layer PCB This project
3D Printed Case 2 ABS/PLA case parts This project

Project Structure

macro_pad/
├── CAD/                 # 3D models and assembly
│   ├── bottom_part.step # Bottom part of the 3D model
│   ├── top_part.step    # Top part of the 3D model
│   └── Pictures/        # Rendered images
├── PCB/                 # KiCAD design files
│   ├── macro_pad.kicad_pro
│   ├── macro_pad.kicad_sch
│   ├── macro_pad.kicad_pcb
│   └── Pictures/        # PCB images
├── Firmware/            # KMK firmware source
│   ├── main.py
│   └── kmk/             # KMK library
├── Production/          # Manufacturing files
│   ├── gerbers.zip      # PCB gerbers
│   ├── top_part.STL     # Case parts
│   ├── bottom_part.STL
│   └── firmware.uf2     # Compiled firmware
└── README.md

Building the Macro Pad

PCB Manufacturing

  1. Download Production/gerbers.zip
  2. Upload to your preferred PCB manufacturer (JLCPCB, PCBWay, etc.)
  3. Order 2-layer PCBs with standard specifications

Case Printing

  1. Use the STL files in Production/ for 3D printing
  2. Print with ABS or PLA, 0.2mm layer height recommended
  3. Assemble with M3 screws

Assembly

  1. Solder components to the PCB
  2. Mount switches
  3. Connect OLED and LEDs
  4. Place PCB in case and secure

Firmware Flashing

  1. Install KMK firmware (see Firmware/ directory)
  2. Put XIAO RP2040 into bootloader mode (double-click reset)
  3. Drag firmware.uf2 to the RPI-RP2 drive

Customization

The firmware is written in Python using KMK. Edit Firmware/main.py to customize key mappings, LED effects, and display output.

Repository

Acknowledgments

This project is submitted as part of the Hackpad community challenge. Special thanks to the KMK firmware developers and the open-source hardware community.

Built with ❤️ using KiCAD, Fusion 360, and KMK

2Source