Merge branch 'master' of https://github.com/qmk/qmk_firmware

30 files changed, 450 insertions, 952 deletions

diff --git a/tmk_core/common/action.c b/tmk_core/common/action.c
index b99c2acaa7..ec8d6ed7b9 100644
--- a/tmk_core/common/action.c
+++ b/tmk_core/common/action.c
@@ -653,7 +653,7 @@ void process_action(keyrecord_t *record, action_t action)
 
 #ifndef NO_ACTION_TAPPING
   #ifdef RETRO_TAPPING
-  if (!is_tap_key(record->event.key)) {
+  if (!is_tap_action(action)) {
     retro_tapping_counter = 0;
   } else {
     if (event.pressed) {
@@ -929,7 +929,15 @@ void clear_keyboard_but_mods_and_keys()
 bool is_tap_key(keypos_t key)
 {
     action_t action = layer_switch_get_action(key);
+    return is_tap_action(action);
+}
 
+/** \brief Utilities for actions. (FIXME: Needs better description)
+ *
+ * FIXME: Needs documentation.
+ */
+bool is_tap_action(action_t action)
+{
     switch (action.kind.id) {
         case ACT_LMODS_TAP:
         case ACT_RMODS_TAP:
diff --git a/tmk_core/common/action.h b/tmk_core/common/action.h
index 8e47e5339e..799e3bb0ef 100644
--- a/tmk_core/common/action.h
+++ b/tmk_core/common/action.h
@@ -97,6 +97,7 @@ void clear_keyboard_but_mods(void);
 void clear_keyboard_but_mods_and_keys(void);
 void layer_switch(uint8_t new_layer);
 bool is_tap_key(keypos_t key);
+bool is_tap_action(action_t action);
 
 #ifndef NO_ACTION_TAPPING
 void process_record_tap_hint(keyrecord_t *record);
diff --git a/tmk_core/common/action_layer.c b/tmk_core/common/action_layer.c
index 120ce3f51b..6ff8c5549b 100644
--- a/tmk_core/common/action_layer.c
+++ b/tmk_core/common/action_layer.c
@@ -17,82 +17,76 @@ uint32_t default_layer_state = 0;
 
 /** \brief Default Layer State Set At user Level
  *
- * FIXME: Needs docs
+ * Run user code on default layer state change
  */
 __attribute__((weak))
 uint32_t default_layer_state_set_user(uint32_t state) {
-    return state;
+  return state;
 }
 
 /** \brief Default Layer State Set At Keyboard Level
  *
- * FIXME: Needs docs
+ *  Run keyboard code on default layer state change
  */
 __attribute__((weak))
 uint32_t default_layer_state_set_kb(uint32_t state) {
-    return default_layer_state_set_user(state);
+  return default_layer_state_set_user(state);
 }
 
 /** \brief Default Layer State Set
  *
- * FIXME: Needs docs
+ * Static function to set the default layer state, prints debug info and clears keys
  */
-static void default_layer_state_set(uint32_t state)
-{
-    state = default_layer_state_set_kb(state);
-    debug("default_layer_state: ");
-    default_layer_debug(); debug(" to ");
-    default_layer_state = state;
-    default_layer_debug(); debug("\n");
+static void default_layer_state_set(uint32_t state) {
+  state = default_layer_state_set_kb(state);
+  debug("default_layer_state: ");
+  default_layer_debug(); debug(" to ");
+  default_layer_state = state;
+  default_layer_debug(); debug("\n");
 #ifdef STRICT_LAYER_RELEASE
-    clear_keyboard_but_mods(); // To avoid stuck keys
+  clear_keyboard_but_mods(); // To avoid stuck keys
 #else
-    clear_keyboard_but_mods_and_keys(); // Don't reset held keys
+  clear_keyboard_but_mods_and_keys(); // Don't reset held keys
 #endif
 }
 
 /** \brief Default Layer Print
  *
- * FIXME: Needs docs
+ * Print out the hex value of the 32-bit default layer state, as well as the value of the highest bit.
  */
-void default_layer_debug(void)
-{
-    dprintf("%08lX(%u)", default_layer_state, biton32(default_layer_state));
+void default_layer_debug(void) {
+  dprintf("%08lX(%u)", default_layer_state, biton32(default_layer_state));
 }
 
 /** \brief Default Layer Set
  *
- * FIXME: Needs docs
+ * Sets the default layer state.
  */
-void default_layer_set(uint32_t state)
-{
-    default_layer_state_set(state);
+void default_layer_set(uint32_t state) {
+  default_layer_state_set(state);
 }
 
 #ifndef NO_ACTION_LAYER
 /** \brief Default Layer Or
  *
- * FIXME: Needs docs
+ * Turns on the default layer based on matching bits between specifed layer and existing layer state
  */
-void default_layer_or(uint32_t state)
-{
-    default_layer_state_set(default_layer_state | state);
+void default_layer_or(uint32_t state) {
+  default_layer_state_set(default_layer_state | state);
 }
 /** \brief Default Layer And
  *
- * FIXME: Needs docs
+ * Turns on default layer based on matching enabled bits between specifed layer and existing layer state
  */
-void default_layer_and(uint32_t state)
-{
-    default_layer_state_set(default_layer_state & state);
+void default_layer_and(uint32_t state) {
+  default_layer_state_set(default_layer_state & state);
 }
 /** \brief Default Layer Xor
  *
- * FIXME: Needs docs
+ * Turns on default layer based on non-matching bits between specifed layer and existing layer state
  */
-void default_layer_xor(uint32_t state)
-{
-    default_layer_state_set(default_layer_state ^ state);
+void default_layer_xor(uint32_t state) {
+  default_layer_state_set(default_layer_state ^ state);
 }
 #endif
 
@@ -104,170 +98,168 @@ uint32_t layer_state = 0;
 
 /** \brief Layer state set user
  *
- * FIXME: Needs docs
+ * Runs user code on layer state change
  */
 __attribute__((weak))
 uint32_t layer_state_set_user(uint32_t state) {
-    return state;
+  return state;
 }
 
 /** \brief Layer state set keyboard
  *
- * FIXME: Needs docs
+ * Runs keyboard code on layer state change
  */
 __attribute__((weak))
 uint32_t layer_state_set_kb(uint32_t state) {
-    return layer_state_set_user(state);
+  return layer_state_set_user(state);
 }
 
 /** \brief Layer state set
  *
- * FIXME: Needs docs
+ * Sets the layer to match the specifed state (a bitmask)
  */
-void layer_state_set(uint32_t state)
-{
-    state = layer_state_set_kb(state);
-    dprint("layer_state: ");
-    layer_debug(); dprint(" to ");
-    layer_state = state;
-    layer_debug(); dprintln();
+void layer_state_set(uint32_t state) {
+  state = layer_state_set_kb(state);
+  dprint("layer_state: ");
+  layer_debug(); dprint(" to ");
+  layer_state = state;
+  layer_debug(); dprintln();
 #ifdef STRICT_LAYER_RELEASE
-    clear_keyboard_but_mods(); // To avoid stuck keys
+  clear_keyboard_but_mods(); // To avoid stuck keys
 #else
-    clear_keyboard_but_mods_and_keys(); // Don't reset held keys
+  clear_keyboard_but_mods_and_keys(); // Don't reset held keys
 #endif
 }
 
 /** \brief Layer clear
  *
- * FIXME: Needs docs
+ * Turn off all layers
  */
-void layer_clear(void)
-{
-    layer_state_set(0);
+void layer_clear(void) {
+  layer_state_set(0);
 }
 
 /** \brief Layer state is
  *
- * FIXME: Needs docs
+ * Return whether the given state is on (it might still be shadowed by a higher state, though)
  */
-bool layer_state_is(uint8_t layer)
-{
-    return layer_state_cmp(layer_state, layer);
+bool layer_state_is(uint8_t layer) {
+  return layer_state_cmp(layer_state, layer);
 }
 
 /** \brief Layer state compare
  *
- * FIXME: Needs docs
+ * Used for comparing layers {mostly used for unit testing}
  */
 bool layer_state_cmp(uint32_t cmp_layer_state, uint8_t layer) {
-    if (!cmp_layer_state) { return layer == 0; }
-    return (cmp_layer_state & (1UL<<layer)) != 0;
+  if (!cmp_layer_state) { return layer == 0; }
+  return (cmp_layer_state & (1UL<<layer)) != 0;
 }
 
 /** \brief Layer move
  *
- * FIXME: Needs docs
+ * Turns on the given layer and turn off all other layers
  */
-void layer_move(uint8_t layer)
-{
-    layer_state_set(1UL<<layer);
+void layer_move(uint8_t layer) {
+  layer_state_set(1UL<<layer);
 }
 
 /** \brief Layer on
  *
- * FIXME: Needs docs
+ * Turns on given layer
  */
-void layer_on(uint8_t layer)
-{
-    layer_state_set(layer_state | (1UL<<layer));
+void layer_on(uint8_t layer) {
+  layer_state_set(layer_state | (1UL<<layer));
 }
 
 /** \brief Layer off
  *
- * FIXME: Needs docs
+ * Turns off given layer
  */
-void layer_off(uint8_t layer)
-{
-    layer_state_set(layer_state & ~(1UL<<layer));
+void layer_off(uint8_t layer) {
+  layer_state_set(layer_state & ~(1UL<<layer));
 }
 
 /** \brief Layer invert
  *
- * FIXME: Needs docs
+ * Toggle the given layer (set it if it's unset, or unset it if it's set)
  */
-void layer_invert(uint8_t layer)
-{
-    layer_state_set(layer_state ^ (1UL<<layer));
+void layer_invert(uint8_t layer) {
+  layer_state_set(layer_state ^ (1UL<<layer));
 }
 
 /** \brief Layer or
  *
- * FIXME: Needs docs
+ * Turns on layers based on matching bits between specifed layer and existing layer state
  */
-void layer_or(uint32_t state)
-{
-    layer_state_set(layer_state | state);
+void layer_or(uint32_t state) {
+  layer_state_set(layer_state | state);
 }
 /** \brief Layer and
  *
- * FIXME: Needs docs
+ * Turns on layers based on matching enabled bits between specifed layer and existing layer state
  */
-void layer_and(uint32_t state)
-{
-    layer_state_set(layer_state & state);
+void layer_and(uint32_t state) {
+  layer_state_set(layer_state & state);
 }
 /** \brief Layer xor
  *
- * FIXME: Needs docs
+ * Turns on layers based on non-matching bits between specifed layer and existing layer state
  */
-void layer_xor(uint32_t state)
-{
-    layer_state_set(layer_state ^ state);
+void layer_xor(uint32_t state) {
+  layer_state_set(layer_state ^ state);
 }
 
 /** \brief Layer debug printing
  *
- * FIXME: Needs docs
+ * Print out the hex value of the 32-bit layer state, as well as the value of the highest bit.
  */
-void layer_debug(void)
-{
-    dprintf("%08lX(%u)", layer_state, biton32(layer_state));
+void layer_debug(void) {
+  dprintf("%08lX(%u)", layer_state, biton32(layer_state));
 }
 #endif
 
 #if !defined(NO_ACTION_LAYER) && !defined(STRICT_LAYER_RELEASE)
+/** \brief source layer cache
+ */
+
 uint8_t source_layers_cache[(MATRIX_ROWS * MATRIX_COLS + 7) / 8][MAX_LAYER_BITS] = {{0}};
 
-void update_source_layers_cache(keypos_t key, uint8_t layer)
-{
-    const uint8_t key_number = key.col + (key.row * MATRIX_COLS);
-    const uint8_t storage_row = key_number / 8;
-    const uint8_t storage_bit = key_number % 8;
-
-    for (uint8_t bit_number = 0; bit_number < MAX_LAYER_BITS; bit_number++) {
-        source_layers_cache[storage_row][bit_number] ^=
-            (-((layer & (1U << bit_number)) != 0)
-             ^ source_layers_cache[storage_row][bit_number])
-            & (1U << storage_bit);
-    }
+/** \brief update source layers cache
+ *
+ * Updates the cached keys when changing layers
+ */
+void update_source_layers_cache(keypos_t key, uint8_t layer) {
+  const uint8_t key_number = key.col + (key.row * MATRIX_COLS);
+  const uint8_t storage_row = key_number / 8;
+  const uint8_t storage_bit = key_number % 8;
+
+  for (uint8_t bit_number = 0; bit_number < MAX_LAYER_BITS; bit_number++) {
+    source_layers_cache[storage_row][bit_number] ^=
+      (-((layer & (1U << bit_number)) != 0)
+        ^ source_layers_cache[storage_row][bit_number])
+      & (1U << storage_bit);
+  }
 }
 
-uint8_t read_source_layers_cache(keypos_t key)
-{
-    const uint8_t key_number = key.col + (key.row * MATRIX_COLS);
-    const uint8_t storage_row = key_number / 8;
-    const uint8_t storage_bit = key_number % 8;
-    uint8_t layer = 0;
-
-    for (uint8_t bit_number = 0; bit_number < MAX_LAYER_BITS; bit_number++) {
-        layer |=
-            ((source_layers_cache[storage_row][bit_number]
-              & (1U << storage_bit)) != 0)
-            << bit_number;
-    }
-
-    return layer;
+/** \brief read source layers cache
+ *
+ * reads the cached keys stored when the layer was changed
+ */
+uint8_t read_source_layers_cache(keypos_t key) {
+  const uint8_t key_number = key.col + (key.row * MATRIX_COLS);
+  const uint8_t storage_row = key_number / 8;
+  const uint8_t storage_bit = key_number % 8;
+  uint8_t layer = 0;
+
+  for (uint8_t bit_number = 0; bit_number < MAX_LAYER_BITS; bit_number++) {
+    layer |=
+      ((source_layers_cache[storage_row][bit_number]
+        & (1U << storage_bit)) != 0)
+      << bit_number;
+  }
+
+  return layer;
 }
 #endif
 
@@ -278,61 +270,58 @@ uint8_t read_source_layers_cache(keypos_t key)
  * when the layer is switched after the down event but before the up
  * event as they may get stuck otherwise.
  */
-action_t store_or_get_action(bool pressed, keypos_t key)
-{
+action_t store_or_get_action(bool pressed, keypos_t key) {
 #if !defined(NO_ACTION_LAYER) && !defined(STRICT_LAYER_RELEASE)
-    if (disable_action_cache) {
-        return layer_switch_get_action(key);
-    }
-
-    uint8_t layer;
-
-    if (pressed) {
-        layer = layer_switch_get_layer(key);
-        update_source_layers_cache(key, layer);
-    }
-    else {
-        layer = read_source_layers_cache(key);
-    }
-    return action_for_key(layer, key);
-#else
+  if (disable_action_cache) {
     return layer_switch_get_action(key);
+  }
+
+  uint8_t layer;
+
+  if (pressed) {
+    layer = layer_switch_get_layer(key);
+    update_source_layers_cache(key, layer);
+  }
+  else {
+    layer = read_source_layers_cache(key);
+  }
+  return action_for_key(layer, key);
+#else
+  return layer_switch_get_action(key);
 #endif
 }
 
 
 /** \brief Layer switch get layer
  *
- * FIXME: Needs docs
+ * Gets the layer based on key info
  */
-int8_t layer_switch_get_layer(keypos_t key)
-{
+int8_t layer_switch_get_layer(keypos_t key) {
 #ifndef NO_ACTION_LAYER
-    action_t action;
-    action.code = ACTION_TRANSPARENT;
-
-    uint32_t layers = layer_state | default_layer_state;
-    /* check top layer first */
-    for (int8_t i = 31; i >= 0; i--) {
-        if (layers & (1UL<<i)) {
-            action = action_for_key(i, key);
-            if (action.code != ACTION_TRANSPARENT) {
-                return i;
-            }
-        }
+  action_t action;
+  action.code = ACTION_TRANSPARENT;
+
+  uint32_t layers = layer_state | default_layer_state;
+  /* check top layer first */
+  for (int8_t i = 31; i >= 0; i--) {
+    if (layers & (1UL<<i)) {
+      action = action_for_key(i, key);
+      if (action.code != ACTION_TRANSPARENT) {
+          return i;
+      }
     }
-    /* fall back to layer 0 */
-    return 0;
+  }
+  /* fall back to layer 0 */
+  return 0;
 #else
-    return biton32(default_layer_state);
+  return biton32(default_layer_state);
 #endif
 }
 
 /** \brief Layer switch get layer
  *
- * FIXME: Needs docs
+ * Gets action code based on key position
  */
-action_t layer_switch_get_action(keypos_t key)
-{
-    return action_for_key(layer_switch_get_layer(key), key);
+action_t layer_switch_get_action(keypos_t key) {
+  return action_for_key(layer_switch_get_layer(key), key);
 }
diff --git a/tmk_core/common/action_util.c b/tmk_core/common/action_util.c
index afd4ae8b25..58401ace55 100644
--- a/tmk_core/common/action_util.c
+++ b/tmk_core/common/action_util.c
@@ -54,7 +54,7 @@ int8_t get_oneshot_locked_mods(void) { return oneshot_locked_mods; }
 void set_oneshot_locked_mods(int8_t mods) { oneshot_locked_mods = mods; }
 void clear_oneshot_locked_mods(void) { oneshot_locked_mods = 0; }
 #if (defined(ONESHOT_TIMEOUT) && (ONESHOT_TIMEOUT > 0))
-static int16_t oneshot_time = 0;
+static uint16_t oneshot_time = 0;
 bool has_oneshot_mods_timed_out(void) {
   return TIMER_DIFF_16(timer_read(), oneshot_time) >= ONESHOT_TIMEOUT;
 }
@@ -79,7 +79,7 @@ inline uint8_t get_oneshot_layer(void) { return oneshot_layer_data >> 3; }
 inline uint8_t get_oneshot_layer_state(void) { return oneshot_layer_data & 0b111; }
 
 #if (defined(ONESHOT_TIMEOUT) && (ONESHOT_TIMEOUT > 0))
-static int16_t oneshot_layer_time = 0;
+static uint16_t oneshot_layer_time = 0;
 inline bool has_oneshot_layer_timed_out() {
     return TIMER_DIFF_16(timer_read(), oneshot_layer_time) >= ONESHOT_TIMEOUT &&
         !(get_oneshot_layer_state() & ONESHOT_TOGGLED);
diff --git a/tmk_core/common/arm_atsam/timer.c b/tmk_core/common/arm_atsam/timer.c
index bcfe5002c3..6c3905e308 100644
--- a/tmk_core/common/arm_atsam/timer.c
+++ b/tmk_core/common/arm_atsam/timer.c
@@ -9,7 +9,7 @@ void set_time(uint64_t tset)
 
 void timer_init(void)
 {
-    ms_clk = 0;
+    timer_clear();
 }
 
 uint16_t timer_read(void)
@@ -37,23 +37,7 @@ uint32_t timer_elapsed32(uint32_t tlast)
     return TIMER_DIFF_32(timer_read32(), tlast);
 }
 
-uint32_t timer_elapsed64(uint32_t tlast)
-{
-    uint64_t tnow = timer_read64();
-    return (tnow >= tlast ? tnow - tlast : UINT64_MAX - tlast + tnow);
-}
-
 void timer_clear(void)
 {
-    ms_clk = 0;
-}
-
-void wait_ms(uint64_t msec)
-{
-    CLK_delay_ms(msec);
-}
-
-void wait_us(uint16_t usec)
-{
-    CLK_delay_us(usec);
+    set_time(0);
 }
diff --git a/tmk_core/common/chibios/eeprom_stm32.c b/tmk_core/common/chibios/eeprom_stm32.c
index a869985501..a15430d676 100755
--- a/tmk_core/common/chibios/eeprom_stm32.c
+++ b/tmk_core/common/chibios/eeprom_stm32.c
@@ -10,664 +10,206 @@
  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  * DEALINGS IN THE SOFTWARE.
  *
- * This files are free to use from https://github.com/rogerclarkmelbourne/Arduino_STM32 and
- * https://github.com/leaflabs/libmaple
+ * This files are free to use from http://engsta.com/stm32-flash-memory-eeprom-emulator/ by
+ * Artur F.
  *
  * Modifications for QMK and STM32F303 by Yiancar
  */
 
+#include <stdio.h>
+#include <string.h>
 #include "eeprom_stm32.h"
+/*****************************************************************************
+ * Allows to use the internal flash to store non volatile data. To initialize
+ * the functionality use the EEPROM_Init() function. Be sure that by reprogramming
+ * of the controller just affected pages will be deleted. In other case the non
+ * volatile data will be lost.
+******************************************************************************/
+
+/* Private macro -------------------------------------------------------------*/
+/* Private variables ---------------------------------------------------------*/
+/* Functions -----------------------------------------------------------------*/
+
+uint8_t DataBuf[FEE_PAGE_SIZE];
+/*****************************************************************************
+*  Delete Flash Space used for user Data, deletes the whole space between
+*  RW_PAGE_BASE_ADDRESS and the last uC Flash Page
+******************************************************************************/
+uint16_t EEPROM_Init(void) {
+    // unlock flash
+    FLASH_Unlock();
 
-    FLASH_Status EE_ErasePage(uint32_t);
-
-    uint16_t EE_CheckPage(uint32_t, uint16_t);
-    uint16_t EE_CheckErasePage(uint32_t, uint16_t);
-    uint16_t EE_Format(void);
-    uint32_t EE_FindValidPage(void);
-    uint16_t EE_GetVariablesCount(uint32_t, uint16_t);
-    uint16_t EE_PageTransfer(uint32_t, uint32_t, uint16_t);
-    uint16_t EE_VerifyPageFullWriteVariable(uint16_t, uint16_t);
-
-    uint32_t PageBase0 = EEPROM_PAGE0_BASE;
-    uint32_t PageBase1 = EEPROM_PAGE1_BASE;
-    uint32_t PageSize = EEPROM_PAGE_SIZE;
-    uint16_t Status = EEPROM_NOT_INIT;
-
-// See http://www.st.com/web/en/resource/technical/document/application_note/CD00165693.pdf
-
-/**
-  * @brief  Check page for blank
-  * @param  page base address
-  * @retval Success or error
-  *     EEPROM_BAD_FLASH:   page not empty after erase
-  *     EEPROM_OK:          page blank
-  */
-uint16_t EE_CheckPage(uint32_t pageBase, uint16_t status)
-{
-    uint32_t pageEnd = pageBase + (uint32_t)PageSize;
-
-    // Page Status not EEPROM_ERASED and not a "state"
-    if ((*(__IO uint16_t*)pageBase) != EEPROM_ERASED && (*(__IO uint16_t*)pageBase) != status)
-        return EEPROM_BAD_FLASH;
-    for(pageBase += 4; pageBase < pageEnd; pageBase += 4)
-        if ((*(__IO uint32_t*)pageBase) != 0xFFFFFFFF)  // Verify if slot is empty
-            return EEPROM_BAD_FLASH;
-    return EEPROM_OK;
-}
-
-/**
-  * @brief  Erase page with increment erase counter (page + 2)
-  * @param  page base address
-  * @retval Success or error
-  *         FLASH_COMPLETE: success erase
-  *         - Flash error code: on write Flash error
-  */
-FLASH_Status EE_ErasePage(uint32_t pageBase)
-{
-    FLASH_Status FlashStatus;
-    uint16_t data = (*(__IO uint16_t*)(pageBase));
-    if ((data == EEPROM_ERASED) || (data == EEPROM_VALID_PAGE) || (data == EEPROM_RECEIVE_DATA))
-        data = (*(__IO uint16_t*)(pageBase + 2)) + 1;
-    else
-        data = 0;
-
-    FlashStatus = FLASH_ErasePage(pageBase);
-    if (FlashStatus == FLASH_COMPLETE)
-        FlashStatus = FLASH_ProgramHalfWord(pageBase + 2, data);
-
-    return FlashStatus;
-}
+    // Clear Flags
+    //FLASH_ClearFlag(FLASH_SR_EOP|FLASH_SR_PGERR|FLASH_SR_WRPERR);
 
-/**
-  * @brief  Check page for blank and erase it
-  * @param  page base address
-  * @retval Success or error
-  *         - Flash error code: on write Flash error
-  *         - EEPROM_BAD_FLASH: page not empty after erase
-  *         - EEPROM_OK:            page blank
-  */
-uint16_t EE_CheckErasePage(uint32_t pageBase, uint16_t status)
-{
-    uint16_t FlashStatus;
-    if (EE_CheckPage(pageBase, status) != EEPROM_OK)
-    {
-        FlashStatus = EE_ErasePage(pageBase);
-        if (FlashStatus != FLASH_COMPLETE)
-            return FlashStatus;
-        return EE_CheckPage(pageBase, status);
-    }
-    return EEPROM_OK;
+    return FEE_DENSITY_BYTES;
 }
+/*****************************************************************************
+*  Erase the whole reserved Flash Space used for user Data
+******************************************************************************/
+void EEPROM_Erase (void) {
 
-/**
-  * @brief  Find valid Page for write or read operation
-  * @param  Page0: Page0 base address
-  *         Page1: Page1 base address
-  * @retval Valid page address (PAGE0 or PAGE1) or NULL in case of no valid page was found
-  */
-uint32_t EE_FindValidPage(void)
-{
-    uint16_t status0 = (*(__IO uint16_t*)PageBase0);        // Get Page0 actual status
-    uint16_t status1 = (*(__IO uint16_t*)PageBase1);        // Get Page1 actual status
-
-    if (status0 == EEPROM_VALID_PAGE && status1 == EEPROM_ERASED)
-        return PageBase0;
-    if (status1 == EEPROM_VALID_PAGE && status0 == EEPROM_ERASED)
-        return PageBase1;
-
-    return 0;
-}
+    int page_num = 0;
 
-/**
-  * @brief  Calculate unique variables in EEPROM
-  * @param  start: address of first slot to check (page + 4)
-  * @param  end: page end address
-  * @param  address: 16 bit virtual address of the variable to excluse (or 0XFFFF)
-  * @retval count of variables
-  */
-uint16_t EE_GetVariablesCount(uint32_t pageBase, uint16_t skipAddress)
-{
-    uint16_t varAddress, nextAddress;
-    uint32_t idx;
-    uint32_t pageEnd = pageBase + (uint32_t)PageSize;
-    uint16_t count = 0;
-
-    for (pageBase += 6; pageBase < pageEnd; pageBase += 4)
-    {
-        varAddress = (*(__IO uint16_t*)pageBase);
-        if (varAddress == 0xFFFF || varAddress == skipAddress)
-            continue;
-
-        count++;
-        for(idx = pageBase + 4; idx < pageEnd; idx += 4)
-        {
-            nextAddress = (*(__IO uint16_t*)idx);
-            if (nextAddress == varAddress)
-            {
-                count--;
-                break;
-            }
-        }
-    }
-    return count;
+    // delete all pages from specified start page to the last page
+    do {
+        FLASH_ErasePage(FEE_PAGE_BASE_ADDRESS + (page_num * FEE_PAGE_SIZE));
+        page_num++;
+    } while (page_num < FEE_DENSITY_PAGES);
 }
+/*****************************************************************************
+*  Writes once data byte to flash on specified address. If a byte is already
+*  written, the whole page must be copied to a buffer, the byte changed and
+*  the manipulated buffer written after PageErase.
+*******************************************************************************/
+uint16_t EEPROM_WriteDataByte (uint16_t Address, uint8_t DataByte) {
 
-/**
-  * @brief  Transfers last updated variables data from the full Page to an empty one.
-  * @param  newPage: new page base address
-  * @param  oldPage: old page base address
-  * @param  SkipAddress: 16 bit virtual address of the variable (or 0xFFFF)
-  * @retval Success or error status:
-  *           - FLASH_COMPLETE: on success
-  *           - EEPROM_OUT_SIZE: if valid new page is full
-  *           - Flash error code: on write Flash error
-  */
-uint16_t EE_PageTransfer(uint32_t newPage, uint32_t oldPage, uint16_t SkipAddress)
-{
-    uint32_t oldEnd, newEnd;
-    uint32_t oldIdx, newIdx, idx;
-    uint16_t address, data, found;
-    FLASH_Status FlashStatus;
-
-    // Transfer process: transfer variables from old to the new active page
-    newEnd = newPage + ((uint32_t)PageSize);
-
-    // Find first free element in new page
-    for (newIdx = newPage + 4; newIdx < newEnd; newIdx += 4)
-        if ((*(__IO uint32_t*)newIdx) == 0xFFFFFFFF)    // Verify if element
-            break;                                  //  contents are 0xFFFFFFFF
-    if (newIdx >= newEnd)
-        return EEPROM_OUT_SIZE;
-
-    oldEnd = oldPage + 4;
-    oldIdx = oldPage + (uint32_t)(PageSize - 2);
-
-    for (; oldIdx > oldEnd; oldIdx -= 4)
-    {
-        address = *(__IO uint16_t*)oldIdx;
-        if (address == 0xFFFF || address == SkipAddress)
-            continue;                       // it's means that power off after write data
-
-        found = 0;
-        for (idx = newPage + 6; idx < newIdx; idx += 4)
-            if ((*(__IO uint16_t*)(idx)) == address)
-            {
-                found = 1;
-                break;
-            }
-
-        if (found)
-            continue;
-
-        if (newIdx < newEnd)
-        {
-            data = (*(__IO uint16_t*)(oldIdx - 2));
-
-            FlashStatus = FLASH_ProgramHalfWord(newIdx, data);
-            if (FlashStatus != FLASH_COMPLETE)
-                return FlashStatus;
+    FLASH_Status FlashStatus = FLASH_COMPLETE;
 
-            FlashStatus = FLASH_ProgramHalfWord(newIdx + 2, address);
-            if (FlashStatus != FLASH_COMPLETE)
-                return FlashStatus;
+    uint32_t page;
+    int i;
 
-            newIdx += 4;
-        }
-        else
-            return EEPROM_OUT_SIZE;
+    // exit if desired address is above the limit (e.G. under 2048 Bytes for 4 pages)
+    if (Address > FEE_DENSITY_BYTES) {
+        return 0;
     }
 
-    // Erase the old Page: Set old Page status to EEPROM_EEPROM_ERASED status
-    data = EE_CheckErasePage(oldPage, EEPROM_ERASED);
-    if (data != EEPROM_OK)
-        return data;
+    // calculate which page is affected (Pagenum1/Pagenum2...PagenumN)