CMDR keyboard 42 (swedish layout)
This HW(PCB) was original made for use with the TeensyLC module and is reused by patching it to fit the rp2040-zero module
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 | BSpc |
| LCtrl | 1! | 2"@ | 3#£ | 4¤$ | 5% | | 6& | 7/{ | 8([ | 9)] | 0=} | Enter |
| Shift | 6& | 7/{ | 8([ | 9)] | 0=} | | <>| | ´`± | '*´ | ¨^~ | +?\ | Shift |
--------------------| Alt | Fn | Spc | | BSpc| Fn |AG+Fn|--------------------
------------------- -------------------
Layer 2 (Fn + Fn)
--------------------------------------- ---------------------------------------
| Esc | F11 | F12 | F13 | F14 |PrSrc| | § | SLk | Gui | OSLk| CpLk| BSpc |
| LCtrl | F15 | F16 | F17 | F18 | F19 | | Left| Down| Up |Right| Del | Enter |
| Shift | F20 | F21 | F22 | F23 | F24 | | Home| PgD | PgU | End | Ins | Shift |
--------------------| Alt | Fn | Spc | | BSpc| 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 layers provide three active maps (primary + two Fn layers) with sticky-lock support.
- High-speed key scanning: 250 µs cadence with enhanced 5-scan debounce (1.25ms) and anti-bounce protection to prevent double characters.
- Status indication driven by the joystick-style heartbeat model:
- Heartbeat green while waiting for USB enumeration.
- Solid green during normal operation; automatic heartbeat idle animation after 5 s inactivity.
- Blue solid / flashing when sticky lock is armed / latched.
- Red solid on firmware error, red flashing for Caps Lock.
- LED turns off during USB suspend for power savings.
- Power management for USB suspend/resume:
- Automatic power saving when USB host suspends device.
- Reduced key scanning frequency (20x slower) during suspend.
- Wake-on-input detection for any key press.
- Immediate resume response when keys are pressed.
Build environment rp2040 Zero
Rust embedded, rp2040 HAL
- Cargo (cargo.toml)
- rustup target add thumbv6m-none-eabi
- cargo install elf2uf2-rs --locked
- Flashing via rp2040 USB bootloader
- Pressing reset/boot button on rp2040 Zero board
- Pressing upper left corner on the keyboard when connecting the usb cable
Hardware
- 1x rp2040 Zero
- 36x Cherry MX compatible switches
- 6x Kailh Choc low profile switches
- 42x 1N4148 diodes
- 1x PCB Gerber files (please see patch instructions)
- 1x MCU cover STL file
- 1x 6x3 Cherry MX mounting jig (optional) STL file