Corne Keyboard – Custom QMK Keymap

This repository contains my custom QMK keymap for the Corne (crkbd) split keyboard. It includes advanced features like a special combos, single tmux mode key, and a gaming mode.

The layout keeps QWERTY on the base layer, places punctuation on Lower (MO(1)), navigation and numbers on Raise (MO(2)), and RGB controls on MO(3). Special combos include Shift+Backspace sending Delete, Shift+| outputting ?, and the Lower+Raise+Esc chord that toggles the Meta key between GUI and Shift for gaming mode.

Legend

• Meta: Left GUI (Windows/Command) key on the thumb; toggles to Shift in gaming mode
• Ctrl+Space: Tmux prefix
• Shift+PrtSc: S(KC_PSCR) as a second screen capture option

Features Overview

• Key Overrides

  • Shift+| = ?
  • Shift+Bksp = Delete

• Gaming Mode Toggle

  • Press Lower+Raise+Esc to toggle the Meta (GUI) thumb key between Windows/Command key (normal) and Shift (gaming mode).
  • In gaming mode, the Meta key becomes Shift to preventing Start menu activation and providing addition key binds.

• RGB Matrix Controls

  • Layer 3 provides RGB toggle, mode, hue, saturation, brightness, speed, and flags adjustments.

• RGB Matrix Effects

  • RGB_MATRIX_SOLID_COLOR
  • RGB_MATRIX_ALPHAS_MODS
  • RGB_MATRIX_GRADIENT_LEFT_RIGHT
  • RGB_MATRIX_CYCLE_SPIRAL
  • RGB_MATRIX_SOLID_REACTIVE_MULTIWIDE

• Layer Layouts

  • Base: QWERTY
  • Layer 1: Symbols
  • Layer 2: Numbers + Navigation
  • Layer 3: RGB + Function keys

Layers Overview

Layer	Description
0	Base QWERTY
1	Symbols (punctuation)
2	Numbers + Navigation
3	RGB Matrix + Function

Installation & Build

Prerequisites

• Install the QMK CLI and toolchains via qmk setup using the official getting-started guide.
• Make sure AVR GCC, dfu-programmer, and (if needed) dfu-util are on your PATH.
• Run qmk doctor to verify your environment before flashing.

Quick Start

1. Clone QMK Firmware.
2. Clone this keymap.

Place this repo under:

<qmk repo root>/keyboards/crkbd/keymaps/freddiehaddad

Build & Flash

qmk config user.keyboard=crkbd
qmk config user.keymap=freddiehaddad
qmk compile --clean
qmk flash

• Connect each half of the Corne when prompted during flashing.
• If the board fails to enter bootloader, hold the reset button and rerun the flash command, then check qmk doctor for warnings.

NOTE: If initial flash fails:

See: Github Issue

dfu-programmer atmega32u4 erase --force

Generate keymap.json

qmk c2json --keyboard crkbd/rev1 --keymap freddiehaddad --output keymap.json keymap.c

Maintaining the Diagrams

• SVG layouts live in assets/ and mirror each QMK layer.
• Update the keycaps and labels whenever keymap.c changes so the README stays accurate.
• If you export PNGs or other variants, regenerate them from the SVG source to keep everything in sync.

References

• QMK Docs
• RGB Matrix
• Combos
• Key Overrides
• QMK Configurator