CMDR keyboard 42

Layout

 Layer 0
 ---------------------------------------      ---------------------------------------
 |  Tab  |  Q  |  W  |  E  |  R  |  T  |      |  Y  |  U  |  I  |  O  |  P  |   Å   |
 | LCtrl |  A  |  S  |  D  |  F  |  G  |      |  H  |  J  |  K  |  L  |  Ö  |   Ä   |
 | Shift |  Z  |  X  |  C  |  V  |  B  |      |  N  |  M  |  ,  |  .  |  -  | Shift |
 --------------------| Alt | Fn  | Spc |      |Enter| Fn  |AG+Fn|--------------------
                     -------------------      -------------------
 Layer 1 (Fn)
 ---------------------------------------      ---------------------------------------
 |  Esc  |  F1 |  F2 |  F3 |  F4 |  F5 |      |  F6 |  F7 |  F8 |  F9 | F10 |       |
 | LCtrl |  1  |  2  |  3  |  4  |  5  |      |  6  |  7  |  8  |  9  |  0  |       |
 | Shift |  6  |  7  |  8  |  9  |  0  |      |  <  |  ´  |  '  |  ¨  |  +  | Shift |
 --------------------| Alt | Fn  | BSpc|      |Enter| Fn  |AG+Fn|--------------------
                     -------------------      -------------------
 Layer 2 (Fn + Fn)
 ---------------------------------------      ---------------------------------------
 |  F11  | F12 | F13 | F14 | F15 | F16 |      |  §  |GuiLK| Gui |     | CpLk|       |
 | LCtrl |     |     | F17 | F18 | F19 |      | Left| Down| Up  |Right| Del |       |
 | Shift | F20 | F21 | F22 | F23 | F24 |      | Home| PgD | PgU | End | Ins | Shift |
 --------------------| Alt | Fn  | Gui |      |Enter| Fn  |AG+Fn|--------------------
                     -------------------      -------------------

Features

• 42 keys "Split" keyboard layout. 36 finger buttons and 6 thumb buttons.
• Extreme low profile (only one pcb).
• Cost efficient solution with one pcb and one 3D printed cover.
• Function keys with total of three layer support (Primary + 2fn layers).
• Status indication -
  • LED off = Normal mode
  • LED flashing = Caps Lock activated
  • LED on = Gui key lock activated

Build environment TeensyLC

C/C++, Teensy arduino framework

• Platformio (platformio.ini)
• Flashing via Teensy USB bootloader
  • Pressing boot button on teensy
  • Pressing all four corners on the keyboard

Build environment rp2040 Zero

Rust embedded, rp2040 HAL

• Cargo (cargo.toml)
• Flashing via rp2040 USB bootloader
  • Pressing reset/boot button on rp2040 Zero board
  • Pressing all four corners on the keyboard

Hardware

Schematics

• 1x TeensyLC alt 1x rp2040 Zero
• 36x Cherry MX compatible switches
• 6x Kailh Choc low profile switches
• 42x 1N4148 diodes
• 1x PCB Gerber files
• 1x MCU cover (optional) STL file
• 1x 6x3 Cherry MX mounting jig (optional) STL file