qmk_firmware/keyboards/handwired/arrow_pad/keymaps/default/keymap.c

#include "arrow_pad.h"
#include "led.h"

// This is the 21-key keypad to 2x11 element matrix mapping
#define LAYOUT( \
    KM_ESC, KM_TAB, KM_BSL, KM_ARR, \
    KM_NUM, KM_FSL, KM_AST, KM_MIN, \
    KM___7, KM___8, KM___9, KM_EQU, \
    KM___4, KM___5, KM___6, KM_PLS, \
    KM___1, KM___2, KM___3, ___ENT, \
    KM___0, _____0, KM_DOT, KM_ENT  \
) { \
    { KM_ESC, KM_TAB, KM_BSL, KM_ARR  }, \
    { KM_NUM, KM_FSL, KM_AST, KM_MIN  }, \
    { KM___7, KM___8, KM___9, KM_EQU  }, \
    { KM___4, KM___5, KM___6, KM_PLS  }, \
    { KM___1, KM___2, KM___3, KC_NO   }, \
    { KM___0, KC_NO,  KM_DOT, KM_ENT  }  \
}

#define LAYER_BASE                      0
#define LAYER_EDIT                      1
#define LAYER_FUNCTION                  2

#define MACRO_COPY_CUT                  0
#define MACRO_SHIFT_CONTROL             1
#define MACRO_CONTROL_ALT               2

#define M_COPY              KC_FN5
#define M_SHFCT             KC_FN6
#define M_CTALT             KC_FN7

#define SC_UNDO             LCTL(KC_Z)
#define SC_REDO             LCTL(KC_Y)
#define SC_CUT              LCTL(KC_X)
#define SC_COPY             LCTL(KC_C)
#define SC_PSTE             LCTL(KC_V)
#define SC_SELA             LCTL(KC_A)
#define SC_SAVE             LCTL(KC_S)
#define SC_OPEN             LCTL(KC_O)
#define SC_ACLS             LALT(KC_F4)
#define SC_CCLS             LCTL(KC_F4)

#define _______             KC_TRNS
#define XXXXXXX             KC_NO

const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {

[LAYER_BASE] = LAYOUT(                \
  KC_ESC,  KC_TAB,  KC_BSLS, KC_FN0,  \
  KC_NLCK, KC_PSLS, KC_PAST, KC_PMNS, \
  KC_P7,   KC_P8,   KC_P9,   KC_PEQL, \
  KC_P4,   KC_P5,   KC_P6,   KC_PPLS, \
  KC_P1,   KC_P2,   KC_P3,   XXXXXXX, \
  KC_P0,   KC_PCMM, KC_PDOT, KC_PENT  ),

[LAYER_EDIT] = LAYOUT(                \
  KC_ESC,  KC_TAB,  KC_SPC,  _______, \
  KC_FN1,  SC_PSTE, SC_REDO, SC_UNDO, \
  KC_HOME, KC_UP,   KC_PGUP, KC_LALT, \
  KC_LEFT, M_COPY,  KC_RGHT, KC_LCTL, \
  KC_END,  KC_DOWN, KC_PGDN, XXXXXXX, \
  KC_BSPC, KC_PENT, KC_DEL,  M_SHFCT),

[LAYER_FUNCTION] = LAYOUT(            \
  KC_FN2,  KC_FN3,  KC_FN4,  _______, \
  KC_FN1,  _______, _______, _______, \
  _______, _______, _______, _______, \
  _______, _______, _______, _______, \
  _______, _______, _______, XXXXXXX, \
  RESET,   _______, _______, _______  ),

};


const uint16_t PROGMEM fn_actions[] = {
	[0] = ACTION_LAYER_MOMENTARY(LAYER_FUNCTION),
	[1] = ACTION_LAYER_TOGGLE(LAYER_EDIT),
	[2] = ACTION_BACKLIGHT_TOGGLE(),
	[3] = ACTION_BACKLIGHT_INCREASE(),
	[4] = ACTION_BACKLIGHT_DECREASE(),
	[5] = ACTION_MACRO_TAP(MACRO_COPY_CUT),
    [6] = ACTION_MACRO_TAP(MACRO_SHIFT_CONTROL),
    [7] = ACTION_MACRO_TAP(MACRO_CONTROL_ALT),

};


void action_function(keyrecord_t *record, uint8_t id, uint8_t opt)
{
}


const macro_t *action_get_macro(keyrecord_t *record, uint8_t id, uint8_t opt)
{
  // MACRODOWN only works in this function
    switch (id) {

    case MACRO_COPY_CUT:
        if (record->event.pressed) {
            register_code(KC_LCTL);
            if (record->tap.count == 1) {
                register_code(KC_C);
                unregister_code(KC_C);
            }
            else if (record->tap.count == 2) {
                register_code(KC_X);
                unregister_code(KC_X);
            }
            unregister_code(KC_LCTL);
        }
        break;

    case MACRO_SHIFT_CONTROL:
        if (record->event.pressed) {
            if (record->tap.count <= 2) register_mods(MOD_BIT(KC_LSFT));
            if (record->tap.count == 2) register_mods(MOD_BIT(KC_LCTL));
            if (record->tap.count == 3) register_code(KC_PENT);;
        }
        else {
            unregister_mods(MOD_BIT(KC_LSFT) | MOD_BIT(KC_LCTL));
            unregister_code(KC_PENT);
        }
        break;

    case MACRO_CONTROL_ALT:
        if (record->event.pressed) {
            if (record->tap.count < 2)  register_mods(MOD_BIT(KC_LCTL));
            if (record->tap.count >= 2) register_mods(MOD_BIT(KC_LALT));
        }
        else {
            unregister_mods(MOD_BIT(KC_LCTL) | MOD_BIT(KC_LALT));
        }
        break;
    }

    return MACRO_NONE;
}

void led_set_user(uint8_t usb_led)
{
    if (usb_led & (1<<USB_LED_CAPS_LOCK)) {
        // output high
        DDRD |= (1<<6);
        PORTD |= (1<<6);
    } else {
        // Hi-Z
        DDRD &= ~(1<<6);
        PORTD &= ~(1<<6);
    }
    if (usb_led & (1<<USB_LED_NUM_LOCK)) {
        // output low
        DDRC |= (1<<7);
        PORTC |= ~(1<<7);
    } else {
        // Hi-Z
        DDRC &= ~(1<<7);
        PORTC &= ~(1<<7);
    }
}