diff --git a/docs/i2c_driver.md b/docs/i2c_driver.md
index 856ca0a9b22..d5c340edce7 100644
--- a/docs/i2c_driver.md
+++ b/docs/i2c_driver.md
@@ -7,7 +7,7 @@ The I2C Master drivers used in QMK have a set of common functions to allow porta
 |Function                                                                                                          |Description                                                                                                                                                                  |
 |------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
 |`void i2c_init(void);`                                                                                            |Initializes the I2C driver. This function should be called once before any transaction is initiated.                                                                         |
-|`uint8_t i2c_start(uint8_t address);`                                                                             |Starts an I2C transaction. Address is the 7-bit slave address without the direction bit.                                                                                     |
+|`uint8_t i2c_start(uint8_t address, uint16_t timeout);`                                                                             |Starts an I2C transaction. Address is the 7-bit slave address without the direction bit.                                                                                     |
 |`uint8_t i2c_transmit(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout);`                        |Transmit data over I2C. Address is the 7-bit slave address without the direction. Returns status of transaction.                                                             |
 |`uint8_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout);`                         |Receive data over I2C. Address is the 7-bit slave address without the direction. Saves number of bytes specified by `length` in `data` array. Returns status of transaction. |
 |`uint8_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout);`       |Same as the `i2c_transmit` function but `regaddr` sets where in the slave the data will be written.                                                                          |
diff --git a/drivers/avr/analog.h b/drivers/avr/analog.h
index 32452a1ec21..1b773d82cef 100644
--- a/drivers/avr/analog.h
+++ b/drivers/avr/analog.h
@@ -19,9 +19,15 @@
 
 #include <stdint.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
 void    analogReference(uint8_t mode);
 int16_t analogRead(uint8_t pin);
 int16_t adc_read(uint8_t mux);
+#ifdef __cplusplus
+}
+#endif
 
 #define ADC_REF_POWER (1 << REFS0)
 #define ADC_REF_INTERNAL ((1 << REFS1) | (1 << REFS0))
diff --git a/keyboards/aeboards/ext65/keymaps/default/keymap.c b/keyboards/aeboards/ext65/keymaps/default/keymap.c
index 79d5ecf5056..efa11cd0fd6 100644
--- a/keyboards/aeboards/ext65/keymaps/default/keymap.c
+++ b/keyboards/aeboards/ext65/keymaps/default/keymap.c
@@ -62,7 +62,6 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
   )
 };
 
-
 void keyboard_pre_init_user(void) {
   // Call the keyboard pre init code.
 
@@ -75,19 +74,19 @@ void keyboard_pre_init_user(void) {
 
 void led_set_user(uint8_t usb_led) {
     if (IS_LED_ON(usb_led, USB_LED_NUM_LOCK)) {
-        writePinLow(D5);
-    } else {
         writePinHigh(D5);
+    } else {
+        writePinLow(D5);
     }
     if (IS_LED_ON(usb_led, USB_LED_CAPS_LOCK)) {
-        writePinLow(D3);
-    } else {
         writePinHigh(D3);
+    } else {
+        writePinLow(D3);
     }
     if (IS_LED_ON(usb_led, USB_LED_SCROLL_LOCK)) {
-        writePinLow(D2);
-    } else {
         writePinHigh(D2);
+    } else {
+        writePinLow(D2);
     }
 }
 
@@ -101,4 +100,4 @@ uint32_t layer_state_set_user(uint32_t state) {
         break;
       }
     return state;
-}
\ No newline at end of file
+}
diff --git a/keyboards/aeboards/ext65/keymaps/via/keymap.c b/keyboards/aeboards/ext65/keymaps/via/keymap.c
index 3079c528eb5..efa11cd0fd6 100644
--- a/keyboards/aeboards/ext65/keymaps/via/keymap.c
+++ b/keyboards/aeboards/ext65/keymaps/via/keymap.c
@@ -32,7 +32,7 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
   [0] = LAYOUT_ext65(
     KC_PMNS, KC_PAST, KC_PSLS, KC_NLCK, KC_ESC , 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_BSLS, KC_GRV , KC_PSCR,
     KC_PPLS, KC_P9  , KC_P8  , KC_P7  , KC_TAB , KC_Q   , KC_W   , KC_E   , KC_R   , KC_T   , KC_Y   , KC_U   , KC_I   , KC_O   , KC_P   , KC_LBRC, KC_RBRC, KC_BSPC,          KC_DEL ,
-    KC_PPLS, KC_P6  , KC_P5  , KC_P4  , KC_LCTL, KC_A   , KC_S   , KC_D   , KC_F   , KC_G   , KC_H   , KC_J   , KC_K   , KC_L   , KC_SCLN, KC_QUOT, KC_ENT ,                   KC_PGUP,
+    KC_PPLS, KC_P6  , KC_P5  , KC_P4  , KC_CAPS, KC_A   , KC_S   , KC_D   , KC_F   , KC_G   , KC_H   , KC_J   , KC_K   , KC_L   , KC_SCLN, KC_QUOT, KC_ENT ,                   KC_PGUP,
     KC_PENT, KC_P3  , KC_P2  , KC_P1  , 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_UP  , KC_PGDN,
     KC_PENT, KC_PDOT, KC_P0  , KC_P0  , KC_LCTL, KC_LGUI, KC_LALT,                            KC_SPC ,                   MO(1)  , KC_RCTL,                   KC_LEFT, KC_DOWN, KC_RGHT
   ),
@@ -74,19 +74,19 @@ void keyboard_pre_init_user(void) {
 
 void led_set_user(uint8_t usb_led) {
     if (IS_LED_ON(usb_led, USB_LED_NUM_LOCK)) {
-        writePinLow(D5);
-    } else {
         writePinHigh(D5);
+    } else {
+        writePinLow(D5);
     }
     if (IS_LED_ON(usb_led, USB_LED_CAPS_LOCK)) {
-        writePinLow(D3);
-    } else {
         writePinHigh(D3);
+    } else {
+        writePinLow(D3);
     }
     if (IS_LED_ON(usb_led, USB_LED_SCROLL_LOCK)) {
-        writePinLow(D2);
-    } else {
         writePinHigh(D2);
+    } else {
+        writePinLow(D2);
     }
 }
 
diff --git a/keyboards/atomic/atomic.c b/keyboards/atomic/atomic.c
index 6f393315eeb..eba5ed61f68 100644
--- a/keyboards/atomic/atomic.c
+++ b/keyboards/atomic/atomic.c
@@ -4,12 +4,9 @@ void matrix_init_kb(void) {
     // put your keyboard start-up code here
     // runs once when the firmware starts up
 
-    MCUCR |= (1<<JTD);
-    MCUCR |= (1<<JTD);
-
     // Turn status LED on
     DDRE |= (1<<6);
     PORTE |= (1<<6);
 
     matrix_init_user();
-}
\ No newline at end of file
+}
diff --git a/keyboards/doro67/multi/keymaps/konstantin/config.h b/keyboards/doro67/multi/keymaps/konstantin/config.h
new file mode 100644
index 00000000000..3c2583e2d46
--- /dev/null
+++ b/keyboards/doro67/multi/keymaps/konstantin/config.h
@@ -0,0 +1,4 @@
+#pragma once
+
+#define LAYER_FN
+#define LAYER_NUMPAD
diff --git a/keyboards/doro67/multi/keymaps/konstantin/keymap.c b/keyboards/doro67/multi/keymaps/konstantin/keymap.c
new file mode 100644
index 00000000000..2b1f06d0fb1
--- /dev/null
+++ b/keyboards/doro67/multi/keymaps/konstantin/keymap.c
@@ -0,0 +1,67 @@
+#include QMK_KEYBOARD_H
+#include "konstantin.h"
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+    /* Base layer
+     * ┌───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┐
+     * │Esc│ 1 │ 2 │ 3 │ 4 │ 5 │ 6 │ 7 │ 8 │ 9 │ 0 │ - │ = │ \ │ ` │PSc│
+     * ├───┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴───┼───┤
+     * │ Tab │ Q │ W │ E │ R │ T │ Y │ U │ I │ O │ P │ [ │ ] │Bspc │Del│
+     * ├─────┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴─────┼───┤
+     * │FnCaps│ A │ S │ D │ F │ G │ H │ J │ K │ L │ ; │ ' │ Enter  │PgU│
+     * ├────┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴────┬───┼───┤
+     * │LSft│RAG│ Z │ X │ C │ V │ B │ N │ M │ , │ . │ / │RShift│ ↑ │PgD│
+     * ├────┼───┴┬──┴─┬─┴───┴───┴┬──┴─┬─┴───┴──┬┴───┼───┴┬─┬───┼───┼───┤
+     * │LCtl│LGui│LAlt│  Space   │FnLk│   Fn   │RAlG│RCtl│ │ ← │ ↓ │ → │
+     * └────┴────┴────┴──────────┴────┴────────┴────┴────┘ └───┴───┴───┘
+     */
+    [L_BASE] = LAYOUT_multi(
+        KC_ESC,  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_BSLS, KC_GRV,  KC_PSCR,
+        KC_TAB,  KC_Q,    KC_W,    KC_E,    KC_R,    KC_T,    KC_Y,    KC_U,    KC_I,    KC_O,    KC_P,    KC_LBRC, KC_RBRC, KC_BSPC,          KC_DEL,
+        FN_CAPS, KC_A,    KC_S,    KC_D,    KC_F,    KC_G,    KC_H,    KC_J,    KC_K,    KC_L,    KC_SCLN, KC_QUOT,          KC_ENT,           KC_PGUP,
+        KC_LSFT, RAL_RGU, KC_Z,    KC_X,    KC_C,    KC_V,    KC_B,    KC_N,    KC_M,    KC_COMM, KC_DOT,  KC_SLSH, KC_RSFT,          KC_UP,   KC_PGDN,
+        KC_LCTL, KC_LGUI, KC_LALT,          KC_SPC,           FNLK,             FN,               RAL_RGU, KC_RCTL, XXXXXXX, KC_LEFT, KC_DOWN, KC_RGHT
+    ),
+
+    /* Fn layer
+     * ┌───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┐
+     * │   │F1 │F2 │F3 │F4 │F5 │F6 │F7 │F8 │F9 │F10│F11│F12│Num│SLk│Pau│
+     * ├───┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴───┼───┤
+     * │ M4  │M2 │M↑ │M1 │M3 │M5 │   │UCM│   │Stp│Ply│Prv│Nxt│Clear│Ins│
+     * ├─────┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴─────┼───┤
+     * │      │M← │M↓ │M→ │MW↑│   │   │   │   │   │   │   │        │Top│
+     * ├────┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴────┬───┼───┤
+     * │    │   │MA0│MA2│MW←│MW→│   │   │App│Vo-│Vo+│Mut│      │PgU│Btm│
+     * ├────┼───┴┬──┴─┬─┴───┴───┴┬──┴─┬─┴───┴──┬┴───┼───┴┬─┬───┼───┼───┤
+     * │    │DtPR│DtNA│   MW↓    │    │        │    │    │ │Hom│PgD│End│
+     * └────┴────┴────┴──────────┴────┴────────┴────┴────┘ └───┴───┴───┘
+     */
+    [L_FN] = LAYOUT_multi(
+        _______, KC_F1,   KC_F2,   KC_F3,   KC_F4,   KC_F5,   KC_F6,   KC_F7,   KC_F8,   KC_F9,   KC_F10,  KC_F11,  KC_F12,  NUMPAD,  KC_SLCK, KC_PAUS,
+        KC_BTN4, KC_BTN2, KC_MS_U, KC_BTN1, KC_BTN3, KC_BTN5, _______, UC_MOD,  _______, KC_MSTP, KC_MPLY, KC_MPRV, KC_MNXT, CLEAR,            KC_INS,
+        _______, KC_MS_L, KC_MS_D, KC_MS_R, KC_WH_U, _______, _______, _______, _______, _______, _______, _______,          _______,          TOP,
+        _______, _______, KC_ACL0, KC_ACL2, KC_WH_L, KC_WH_R, _______, _______, KC_APP,  KC_VOLD, KC_VOLU, KC_MUTE, _______,          KC_PGUP, BOTTOM,
+        _______, DST_P_R, DST_N_A,          KC_WH_D,          _______,          _______,          _______, _______, XXXXXXX, KC_HOME, KC_PGDN, KC_END
+    ),
+
+    /* Numpad layer
+     * ┌───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┐
+     * │   │   │   │   │   │   │   │P7 │P8 │P9 │P- │ − │ = │Num│   │   │
+     * ├───┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴───┼───┤
+     * │     │   │   │   │   │   │   │P4 │P5 │P6 │P+ │ ( │ ) │     │   │
+     * ├─────┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴┬──┴─────┼───┤
+     * │      │   │   │   │   │   │   │P1 │P2 │P3 │P* │ × │ PEnter │   │
+     * ├────┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴────┬───┼───┤
+     * │    │   │   │   │   │   │   │P0 │P0 │ , │P. │P/ │  ÷   │   │   │
+     * ├────┼───┴┬──┴─┬─┴───┴───┴┬──┴─┬─┴───┴──┬┴───┼───┴┬─┬───┼───┼───┤
+     * │    │    │    │          │    │        │    │    │ │   │   │   │
+     * └────┴────┴────┴──────────┴────┴────────┴────┴────┘ └───┴───┴───┘
+     */
+    [L_NUMPAD] = LAYOUT_multi(
+        _______, _______, _______, _______, _______, _______, _______, KC_P7,   KC_P8,   KC_P9,   KC_PMNS, MINUS,   EQUALS,  NUMPAD,  _______, _______,
+        _______, _______, _______, _______, _______, _______, _______, KC_P4,   KC_P5,   KC_P6,   KC_PPLS, L_PAREN, R_PAREN, _______,          _______,
+        _______, _______, _______, _______, _______, _______, _______, KC_P1,   KC_P2,   KC_P3,   KC_PAST, TIMES,            KC_PENT,          _______,
+        _______, _______, _______, _______, _______, _______, _______, KC_P0,   KC_P0,   COMMA,   KC_PDOT, KC_PSLS, DIVIDE,           _______, _______,
+        _______, _______, _______,          _______,          _______,          _______,          _______, _______, XXXXXXX, _______, _______, _______
+    ),
+};
diff --git a/keyboards/doro67/multi/keymaps/konstantin/rules.mk b/keyboards/doro67/multi/keymaps/konstantin/rules.mk
new file mode 100644
index 00000000000..041d3211459
--- /dev/null
+++ b/keyboards/doro67/multi/keymaps/konstantin/rules.mk
@@ -0,0 +1,10 @@
+BACKLIGHT_ENABLE   = no
+BOOTMAGIC_ENABLE   = no
+COMMAND_ENABLE     = yes
+CONSOLE_ENABLE     = yes
+EXTRAKEY_ENABLE    = yes
+MOUSEKEY_ENABLE    = yes
+NKRO_ENABLE        = yes
+SPACE_CADET_ENABLE = no
+TAP_DANCE_ENABLE   = yes
+UNICODEMAP_ENABLE  = yes
diff --git a/keyboards/ergodone/keymaps/vega/keymap.c b/keyboards/ergodone/keymaps/vega/keymap.c
index 9e5229528d9..ee6c56bf958 100644
--- a/keyboards/ergodone/keymaps/vega/keymap.c
+++ b/keyboards/ergodone/keymaps/vega/keymap.c
@@ -426,8 +426,8 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
 
 [FNLR] = LAYOUT_ergodox(
        // left hand
-       KC_NO,   KC_F1,  KC_F2,  KC_F3,  KC_F4,  KC_F5,  KC_NO,
-       KC_NO,KC_F11, KC_F12, KC_F13,KC_F14, KC_F15,  KC_NO,
+       UC_M_LN,   KC_F1,  KC_F2,  KC_F3,  KC_F4,  KC_F5,  KC_NO,
+       UC_M_WC,KC_F11, KC_F12, KC_F13,KC_F14, KC_F15,  KC_NO,
        KC_NO,KC_F21, KC_F22, KC_F23,KC_F24, KC_NO,
        KC_NO,KC_PAUSE,KC_PSCR,KC_SLCK,KC_NO,KC_NO,KC_NO,
           EEP_RST,TO(BASE),TO(BASE),TO(BASE),TO(BASE),
diff --git a/keyboards/kbdfans/kbd6x/keymaps/konstantin/keymap.c b/keyboards/kbdfans/kbd6x/keymaps/konstantin/keymap.c
index 00c6e59bc7d..1ca4dadb1bc 100644
--- a/keyboards/kbdfans/kbd6x/keymaps/konstantin/keymap.c
+++ b/keyboards/kbdfans/kbd6x/keymaps/konstantin/keymap.c
@@ -30,17 +30,17 @@ bool process_record_keymap(uint16_t keycode, keyrecord_t *record) {
     return true;
 }
 
-static inline void fn_light() {
+static inline void fn_light(void) {
     rgblight_mode_noeeprom(RGBLIGHT_MODE_STATIC_LIGHT);
     rgblight_sethsv_noeeprom(modern_dolch_red.h, modern_dolch_red.s, rgblight_get_val());
 }
 
-static inline void caps_light() {
+static inline void caps_light(void) {
     rgblight_mode_noeeprom(RGBLIGHT_MODE_STATIC_LIGHT);
     rgblight_sethsv_noeeprom(modern_dolch_cyan.h, modern_dolch_cyan.s, rgblight_get_val());
 }
 
-static inline void restore_light() {
+static inline void restore_light(void) {
     rgblight_config_t saved = { .raw = eeconfig_read_rgblight() };
     rgblight_sethsv_noeeprom(saved.hue, saved.sat, saved.val);
     rgblight_mode_noeeprom(saved.mode);
@@ -108,7 +108,7 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
         XXXXXXX, KC_LGUI, KC_LALT,                            KC_SPC,                             RAL_RGU, RCTRL,   XXXXXXX
     ),
 
-    /* Function layer
+    /* Fn layer
      * ┌───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┐
      * │   │F1 │F2 │F3 │F4 │F5 │F6 │F7 │F8 │F9 │F10│F11│F12│PSc│Ins│
      * ├───┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴───┤
diff --git a/keyboards/maartenwut/wasdat/keymaps/konstantin/keymap.c b/keyboards/maartenwut/wasdat/keymaps/konstantin/keymap.c
index e594edcb23a..04355749ab3 100644
--- a/keyboards/maartenwut/wasdat/keymaps/konstantin/keymap.c
+++ b/keyboards/maartenwut/wasdat/keymaps/konstantin/keymap.c
@@ -27,7 +27,7 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
         KC_LCTL, KC_LGUI, KC_LALT,                            KC_SPC,                             KC_RALT, KC_RGUI, FN_FNLK, KC_RCTL, KC_LEFT, KC_DOWN, KC_RGHT
     ),
 
-    /* Function layer
+    /* Fn layer
      * ┌───┐   ┌───┬───┬───┬───┐ ┌───┬───┬───┬───┐ ┌───┬───┬───┬───┐┌───┬───┬───┐
      * │   │   │   │   │   │   │ │   │   │   │   │ │   │   │   │   ││   │Num│   │
      * └───┘   └───┴───┴───┴───┘ └───┴───┴───┴───┘ └───┴───┴───┴───┘└───┴───┴───┘
diff --git a/keyboards/melody96/keymaps/konstantin/keymap.c b/keyboards/melody96/keymaps/konstantin/keymap.c
index 13f222422d3..1ee7ca1e776 100644
--- a/keyboards/melody96/keymaps/konstantin/keymap.c
+++ b/keyboards/melody96/keymaps/konstantin/keymap.c
@@ -51,7 +51,7 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
         KC_LCTL, KC_LGUI, KC_LALT,                            KC_SPC,                             RAL_RGU, XXXXXXX, FN_FNLK, KC_LEFT, KC_DOWN, KC_RGHT, KC_P0,   KC_PDOT, KC_PENT
     ),
 
-    /* Function layer
+    /* Fn layer
      * ┌───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┐
      * │   │   │   │   │   │   │   │   │   │   │   │   │   │Sys│SLk│Pau│Brk│Top│Btm│
      * ├───┼───┼───┼───┼───┼───┼───┼───┼───┼───┼───┼───┼───┼───┼───┼───┼───┼───┼───┤
diff --git a/keyboards/whitefox/keymaps/konstantin/keymap.c b/keyboards/whitefox/keymaps/konstantin/keymap.c
index 61dcbebda17..4c587dd272f 100644
--- a/keyboards/whitefox/keymaps/konstantin/keymap.c
+++ b/keyboards/whitefox/keymaps/konstantin/keymap.c
@@ -23,7 +23,7 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
         KC_LCTL, KC_LGUI, KC_LALT,                            KC_SPC,                    RAL_RGU, FN_FNLK,                   KC_LEFT, KC_DOWN, KC_RGHT
     ),
 
-    /* Function layer
+    /* Fn layer
      * ┌───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┐
      * │   │F1 │F2 │F3 │F4 │F5 │F6 │F7 │F8 │F9 │F10│F11│F12│Num│SLk│Pau│
      * ├───┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴─┬─┴───┼───┤
diff --git a/tmk_core/protocol/lufa.mk b/tmk_core/protocol/lufa.mk
index bb82a31e17c..d7d1d9ffccf 100644
--- a/tmk_core/protocol/lufa.mk
+++ b/tmk_core/protocol/lufa.mk
@@ -29,6 +29,7 @@ ifeq ($(strip $(BLUETOOTH_ENABLE)), yes)
 endif
 
 ifeq ($(strip $(BLUETOOTH)), AdafruitBLE)
+		LUFA_SRC += analog.c
 		LUFA_SRC += $(LUFA_DIR)/adafruit_ble.cpp
 endif
 
@@ -51,6 +52,7 @@ SRC += $(LUFA_SRC)
 # Search Path
 VPATH += $(TMK_PATH)/$(LUFA_DIR)
 VPATH += $(LUFA_PATH)
+VPATH += $(DRIVER_PATH)/avr
 
 # Option modules
 #ifdef $(or MOUSEKEY_ENABLE, PS2_MOUSE_ENABLE)
diff --git a/tmk_core/protocol/lufa/adafruit_ble.cpp b/tmk_core/protocol/lufa/adafruit_ble.cpp
index 71d0936f8f4..1d8ae1038ba 100644
--- a/tmk_core/protocol/lufa/adafruit_ble.cpp
+++ b/tmk_core/protocol/lufa/adafruit_ble.cpp
@@ -10,6 +10,7 @@
 #include "action_util.h"
 #include "ringbuffer.hpp"
 #include <string.h>
+#include "analog.h"
 
 // These are the pin assignments for the 32u4 boards.
 // You may define them to something else in your config.h
@@ -29,6 +30,12 @@
 #define SAMPLE_BATTERY
 #define ConnectionUpdateInterval 1000 /* milliseconds */
 
+#ifdef SAMPLE_BATTERY
+#ifndef BATTERY_LEVEL_PIN
+#    define BATTERY_LEVEL_PIN 7
+#endif
+#endif
+
 static struct {
     bool is_connected;
     bool initialized;
@@ -631,15 +638,10 @@ void adafruit_ble_task(void) {
     }
 
 #ifdef SAMPLE_BATTERY
-    // I don't know if this really does anything useful yet; the reported
-    // voltage level always seems to be around 3200mV.  We may want to just rip
-    // this code out.
     if (timer_elapsed(state.last_battery_update) > BatteryUpdateInterval && resp_buf.empty()) {
         state.last_battery_update = timer_read();
 
-        if (at_command_P(PSTR("AT+HWVBAT"), resbuf, sizeof(resbuf))) {
-            state.vbat = atoi(resbuf);
-        }
+        state.vbat = analogRead(BATTERY_LEVEL_PIN);
     }
 #endif
 }
diff --git a/users/konstantin/konstantin.c b/users/konstantin/konstantin.c
index 98b11b3a914..9cee25ac664 100644
--- a/users/konstantin/konstantin.c
+++ b/users/konstantin/konstantin.c
@@ -36,9 +36,15 @@ bool process_record_user(uint16_t keycode, keyrecord_t *record) {
 #ifdef LAYER_FN
         static bool fn_lock = false;
 
+    case FNLK:
+        if (record->event.pressed) {
+            fn_lock = !IS_LAYER_ON(L_FN);  // Fn layer will be toggled after this
+        }
+        break;
+
     case FN_FNLK:
         if (record->event.pressed && record->tap.count == TAPPING_TOGGLE) {
-            fn_lock = !IS_LAYER_ON(L_FN);  // Fn layer will be toggled after this
+            fn_lock = !IS_LAYER_ON(L_FN);
         }
         break;
 #endif