rktk is a keyboard firmware framework written in Rust.
Currently, rktk supports nRF52840 and RP2040, and although there are bugs and performance issues (especially related to split keyboards), it can be used as a decent keyboard.
This firmware consists of two parts: the core functionality implemented in the
rktk crate and the driver that actually interacts with the hardware. This
makes it easy to extend.
Crates
| Crate | crates.io | docs.rs |
|---|---|---|
| rktk |  |
 |
| rktk-drivers-common |  |
 |
| rktk-drivers-nrf |  |
 |
| rktk-drivers-rp |  |
 |
| rktk-keymanager |  |
 |
| rktk-cli |  |
|
| rktk-rrp |  |
 |
| rktk-rrp-client-webhid |  |
 |
Features
- ✅ : Working
- 🔵 : Almost working
- 🟡 : Partially working, missing some features
- 🔴 : Planned.
- ❌ : Not planned.
- (blank): Not needed.
Core features
| Feature | Status |
|---|---|
| Keyscan | ✅ |
| Mouse | ✅ |
| Encoder | 🔵 |
| Key mapping | 🟡 (See below table for detail) |
| Hook system | 🟡 |
| Split keyboard | ✅ |
| Non-Split keyboard | 🔵 |
| Display | 🟡 |
| RGB led | 🟡 |
| USB | ✅ |
| Bluetooth | 🟡 |
| Remapper support | 🟡 |
| Double-tap reset | ✅ |
Key mapping features
Key mapping features is implemented in rktk-keymanager and this crate does not
depend on rktk or embassy. Keymap is defined as normal two-dimensional array.
See keyball61's keymap for example.
| Feature name | Status | |
|---|---|---|
| Key action | ||
| Mod-Tap | ✅ | Unlike QMK, any keycode can be specified as modifier. |
| Tap-Hold | 🟡 | Currently, this behaves like HOLD_ON_OTHER_KEY_PRESS. |
| Tap Dance | ✅ | |
| Oneshot key | ✅ | |
| KeyCode | ||
| Normal key | ✅ | |
| Modifier key | ✅ | |
| Media key | ✅ | |
| Mouse key | ✅ | |
| Mouse scroll momentary | ✅ | |
| Layer momentary (MO) | ✅ | |
| Layer toggle (TG) | ✅ |
Drivers
- "Common" means that the driver is implemented in
rktk-drivers-common. Drivers implemented inrktk-drivers-commonuse embassy traits, so they can be easily ported to various platforms.
| Driver | Common | RP2040 | NRF52840 |
|---|---|---|---|
| Key scanner | |||
| Matrix | 🔴 | 🔴 | 🔴 |
| Matrix with shift register | 🔵 | 🔴 | 🔵 |
| (Japanese) Duplex-Matrix | ✅ | ✅ | ✅ |
| Mouse | |||
| PMW3360 | ✅ | ✅ | ✅ |
| PAW3395 | ✅ | ✅ | ✅ |
| Host communication | |||
| USB | ✅ | ✅ | ✅ |
| Bluetooth | ❌ | ❌ | ✅ (SoftDevice) |
| Display | |||
| SSD1306 | ✅ | ✅ | ✅ |
| Split | |||
| Half-duplex single wire | ✅ (PIO) | ✅ (UART) | |
| Full-duplex dual wire | 🔴 (UART) | 🔴 (UART) | |
| Bluetooth | ❌ | 🔴 | |
| RGB led | |||
| WS2812 | ✅ (PIO) | ✅ (PWM) | |
| Double-tap reset | ✅ |
Development
See cargo x --help and .vscode/tasks.json to build firmware and start
development.
Dependencies
You need to install some tools to generate firmware.
arm-none-eabi-objcopy: Required to generate uf2 firmware for nRF52840wasm-pack: Required to build rktk-client
MSRV
rktk actually doesn't depends on nightly feature of rustc, but uses nightly
cargo features like per-package-target. So, it requires nightly toolchain.
Creating new keyboard
Currently, there is no guide for building a new keyboard, but you can refer to the following repository:
Please note that currently driver for regular matrix is not implemented.
Credits & Acknowledgements
- rumcake: RP2040 double-tap-reset driver
- uf2: uf2conv.py, uf2families.json
- rust-dilemma: RP2040 Half-duplex communication
- qmk: RP2040 Half-duplex communication
- rmk: bluetooth implemention