qmk-dactyl-manuform-a/keyboards/pearl/keymaps/jetpacktuxedo/keymap.c

#include QMK_KEYBOARD_H

const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
  [0] = LAYOUT_all(
    KC_GESC,       KC_Q, KC_W, KC_E, KC_R, KC_T, KC_Y, KC_U, KC_I,    KC_O,    KC_P,    KC_LBRC, KC_RBRC,
    LT(2, KC_TAB), KC_A, KC_S, KC_D, KC_F, KC_G, KC_H, KC_J, KC_K,    KC_L,    KC_SCLN, LT(2,KC_ENT),
    KC_LSFT,       KC_Z, KC_X, KC_C, KC_V, KC_B, KC_N, KC_M, KC_COMM, KC_DOT,  KC_SLSH, KC_RSFT,
    KC_LCTL,    KC_LGUI, KC_LALT,    KC_BSPC,    KC_NO,      LT(1, KC_SPC),    MO(3), KC_RALT
  ),
  [1] = LAYOUT_all(
    KC_GRV,  KC_1,  KC_2,  KC_3,  KC_4,  KC_5,  KC_6,  KC_7,  KC_8,  KC_9,  KC_0,    KC_MINS, KC_EQL,
    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_LEFT, KC_DOWN, KC_UP,   KC_RGHT, KC_QUOT, KC_TRNS,
    KC_TRNS, RGB_TOG, RGB_MOD, RGB_VAI, RGB_VAD, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_BSLS, KC_TRNS,
    KC_TRNS, KC_TRNS, KC_TRNS, KC_DEL,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS
  ),
  [2] = LAYOUT_all(
    KC_TILD, KC_EXLM, KC_AT, KC_HASH, KC_DLR, KC_PERC, KC_CIRC, KC_AMPR, KC_ASTR, KC_LPRN, KC_RPRN, KC_UNDS, KC_PLUS,
    KC_TRNS, RGB_SAI, RGB_SAD, KC_TRNS, KC_TRNS, KC_TRNS, KC_HOME, KC_PGDN, KC_PGUP, KC_END, KC_DQUO, KC_TRNS,
    KC_TRNS, RGB_HUI, RGB_HUD, RGB_VAI, RGB_VAD, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_PIPE, KC_TRNS,
    KC_TRNS, KC_TRNS, KC_TRNS, KC_DEL,  KC_TRNS, KC_TRNS,  KC_TRNS, KC_TRNS
  ),
  [3] = LAYOUT_all(
    KC_TRNS, KC_F1,   KC_F2,   KC_F3,   KC_F4,   KC_F5,   KC_F6,   KC_F7,   KC_F8,   KC_F9,   KC_F10,  KC_TRNS, RESET,
    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
    KC_TRNS, BL_TOGG, KC_TRNS, BL_INC,  BL_DEC,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS
  ),
};

uint32_t layer_state_set_kb(uint32_t state) {
  // if we are on layer 1
  if (state & (1<<1)){
    // light num lock led
    PORTD |= (1 << PD0);
  }
  else{
    PORTD &= ~(1 << PD0);
  }
  // if we are on layer 2
  if (state & (1<<2)){
    // light caps lock led
    PORTD |= (1 << PD1);
  }
  else{
    PORTD &= ~(1 << PD1);
  }
  // if we are on layer 3
  if (state & (1<<3)){
    // light scroll lock led
    PORTD |= (1 << PD6);
  }
  else{
    PORTD &= ~(1 << PD6);
  }
    return state;
}