Pros of crkbd

• Established and widely adopted split keyboard design
• Extensive documentation and community support
• Versatile PCB design with various switch and LED options

Cons of crkbd

• Wired connection only, limiting portability
• Requires more components and assembly compared to nrfmicro-based designs

Code Comparison

crkbd (QMK firmware):

const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
  [_QWERTY] = LAYOUT(
    KC_TAB,  KC_Q,    KC_W,    KC_E,    KC_R,    KC_T,
    KC_LCTL, KC_A,    KC_S,    KC_D,    KC_F,    KC_G
  ),
};

nrfmicro (ZMK firmware):

/ {
    keymap {
        compatible = "zmk,keymap";
        default_layer {
            bindings = <
                &kp TAB   &kp Q &kp W &kp E &kp R &kp T
                &kp LCTRL &kp A &kp S &kp D &kp F &kp G
            >;
        };
    };
};

The code comparison shows the different firmware and configuration approaches between the two projects. crkbd uses QMK firmware with C-based keymap definitions, while nrfmicro typically uses ZMK firmware with devicetree syntax for keymap configuration.

Pros of ZMK

• More comprehensive firmware ecosystem with broader device support
• Active community development and frequent updates
• Better documentation and user guides

Cons of ZMK

• Steeper learning curve for beginners
• Requires more setup and configuration

Code Comparison

nrfmicro:

#define MATRIX_ROW_PINS { 8, 9, 10, 11 }
#define MATRIX_COL_PINS { 21, 23, 2, 3, 4, 5, 6 }

ZMK:

&kscan0 {
    col-gpios
        = <&gpio0 8 GPIO_ACTIVE_HIGH>
        , <&gpio0 6 GPIO_ACTIVE_HIGH>
        , <&gpio0 15 GPIO_ACTIVE_HIGH>
        , <&gpio0 17 GPIO_ACTIVE_HIGH>
        , <&gpio0 20 GPIO_ACTIVE_HIGH>
        , <&gpio0 22 GPIO_ACTIVE_HIGH>
        , <&gpio0 24 GPIO_ACTIVE_HIGH>
        ;
};

nrfmicro is a specific firmware project for nRF52-based custom keyboards, while ZMK is a more comprehensive firmware ecosystem for various wireless keyboards. ZMK offers broader device support and more active community development, but it may be more complex for beginners. nrfmicro is simpler and more focused on specific hardware, making it potentially easier for newcomers to get started with custom keyboard firmware development.

Pros of qmk_firmware

• Extensive support for a wide range of keyboard layouts and hardware
• Large community with frequent updates and contributions
• Comprehensive documentation and tutorials

Cons of qmk_firmware

• Steeper learning curve for beginners
• Requires more setup and configuration for custom keyboards

Code Comparison

nrfmicro:

#define MATRIX_ROW_PINS { 8, 9, 10, 11 }
#define MATRIX_COL_PINS { 2, 3, 4, 5, 6, 7 }
#define DIODE_DIRECTION COL2ROW

qmk_firmware:

#define MATRIX_ROW_PINS { D0, D1, D2, D3 }
#define MATRIX_COL_PINS { F0, F1, F4, F5, F6, F7 }
#define DIODE_DIRECTION COL2ROW

Both repositories use similar pin definitions for keyboard matrix setup, but nrfmicro uses numeric pin identifiers, while qmk_firmware uses port-specific identifiers. This reflects the different hardware focus of each project, with nrfmicro targeting specific nRF52 microcontrollers and qmk_firmware supporting a broader range of hardware platforms.

Pros of TinyUSB

• Broader device support, including multiple microcontroller families
• More comprehensive USB stack implementation
• Active development and larger community support

Cons of TinyUSB

• Steeper learning curve for beginners
• May require more configuration for specific use cases

Code Comparison

nrfmicro:

#include "nrf_gpio.h"
#include "nrf_drv_usbd.h"

void usb_init(void) {
    nrf_drv_usbd_init(NULL);
}

TinyUSB:

#include "tusb.h"

void usb_init(void) {
    tusb_init();
}

Key Differences

nrfmicro is specifically designed for nRF52 microcontrollers, offering a streamlined approach for these devices. It provides a simpler setup process for users familiar with nRF52 chips.

TinyUSB, on the other hand, is a more versatile and comprehensive USB stack that supports various microcontroller families. It offers a wider range of USB functionalities and device classes, making it suitable for diverse projects.

While nrfmicro may be easier to get started with for nRF52-based projects, TinyUSB provides greater flexibility and long-term scalability for USB implementations across different platforms.