qmk_firmware/keyboards/amjpad/keymaps/default/keymap.c

#include QMK_KEYBOARD_H

#ifdef RGBLIGHT_ENABLE
#include "rgblight.h"
#endif

// Used for SHIFT_ESC
#define MODS_CTRL_MASK  (MOD_BIT(KC_LSHIFT)|MOD_BIT(KC_RSHIFT))

// Each layer gets a name for readability, which is then used in the keymap matrix below.
// The underscores don't mean anything - you can have a layer called STUFF or any other name.
// Layer names don't all need to be of the same length, obviously, and you can also skip them
// entirely and just use numbers.
#define _BL 0
#define _FL 1

#define _______ KC_TRNS

const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
  /* Keymap _BL: (Base Layer) Default Layer
   * ,-------------------.
   * |Esc |TAB |BS  | =  |
   * |----|----|----|----|
   * | NL | /  | *  | -  |
   * |----|----|----|----|
   * | 7  | 8  | 9  |    |
   * |----|----|----| +  |
   * | 4  | 5  | 6  |    |
   * |----|----|----|----|
   * | 1  | 2  | 3  |    |
   * |----|----|----| En |
   * |   0     |./FN|    |
   * `-------------------'
   */

  [_BL] = LAYOUT_numpad_6x4(
    KC_ESC,  KC_TAB,  KC_BSPC, KC_PEQL, \
    KC_NLCK, KC_PSLS, KC_PAST, KC_PMNS, \
    KC_P7,   KC_P8,   KC_P9,   \
    KC_P4,   KC_P5,   KC_P6,   KC_PPLS, \
    KC_P1,   KC_P2,   KC_P3,   \
      KC_P0, LT(_FL,KC_PDOT),  KC_PENT  \
  ),

  /* Keymap _FL: Function Layer
   * ,-------------------.
   * |Esc |TAB |BS  | =  |
   * |----|----|----|----|
   * | NL | /  | *  | -  |
   * |----|----|----|----|
   * | 7  | 8  | 9  |    |
   * |----|----|----|RST |
   * | 4  | 5  | 6  |    |
   * |----|----|----|----|
   * | 1  | 2  | 3  |    |
   * |----|----|----| En |
   * |   0     |./FN|    |
   * `-------------------'
   */
  [_FL] = LAYOUT_numpad_6x4(
    KC_ESC,  KC_TAB,  KC_BSPC, KC_PEQL, \
    KC_NLCK, KC_PSLS, KC_PAST, KC_PMNS, \
    KC_P7,   KC_P8,   KC_P9,   \
    KC_P4,   KC_P5,   KC_P6,   RESET,   \
    KC_P1,   KC_P2,   KC_P3,   \
      KC_P0, LT(_FL,KC_PDOT),  KC_PENT \
  ),
};

enum function_id {
    SHIFT_ESC,
};

const uint16_t PROGMEM fn_actions[] = {
  [0]  = ACTION_FUNCTION(SHIFT_ESC),
};

void action_function(keyrecord_t *record, uint8_t id, uint8_t opt) {
  static uint8_t shift_esc_shift_mask;
  switch (id) {
    case SHIFT_ESC:
      shift_esc_shift_mask = get_mods()&MODS_CTRL_MASK;
      if (record->event.pressed) {
        if (shift_esc_shift_mask) {
          add_key(KC_GRV);
          send_keyboard_report();
        } else {
          add_key(KC_ESC);
          send_keyboard_report();
        }
      } else {
        if (shift_esc_shift_mask) {
          del_key(KC_GRV);
          send_keyboard_report();
        } else {
          del_key(KC_ESC);
          send_keyboard_report();
        }
      }
      break;
  }
}