diff --git a/Code/picocalc_keyboard/backlight.ino b/Code/picocalc_keyboard/backlight.ino
index b531267..a647b07 100644
--- a/Code/picocalc_keyboard/backlight.ino
+++ b/Code/picocalc_keyboard/backlight.ino
@@ -22,8 +22,9 @@ void lcd_backlight_update(int v) {
 
   val = reg_get_value(REG_ID_BKL);
   val += v;
-  if(val < 0) val = 0;
-  if(val > 0xff) val = 0xff;
+  val = ( val / LCD_BACKLIGHT_STEP ) * LCD_BACKLIGHT_STEP;
+  if(val < LCD_BACKLIGHT_STEP) val =  LCD_BACKLIGHT_STEP;
+  if(val > 240) val = 240;
  
   analogWriteFrequency(10000); 
   analogWrite(PA8, val);  
@@ -35,8 +36,9 @@ void kbd_backlight_update(int v){
 
   val = reg_get_value(REG_ID_BK2);
   val += v;
-  if(val < 20 ) val = 0;
-  if(val > 0xff) val = 0;
+  val = ( val / KBD_BACKLIGHT_STEP ) * KBD_BACKLIGHT_STEP;
+  if(val < KBD_BACKLIGHT_STEP) val = 0;
+  if(val > 240) val = 0;
  
   analogWriteFrequency(10000); 
   analogWrite(PC8, val);  
@@ -50,8 +52,8 @@ void kbd_backlight_update_offset(){
   
   val = reg_get_value(REG_ID_BK2);
   val += kbd_backlight_segs[kbd_backlight_offset];
-  if(val < 20 ) val = 0;
-  if(val > 0xff) val = 0;
+  if(val < 0x20) val = 0;
+  if(val > 0xf0) val = 0;
  
   analogWriteFrequency(10000); 
   analogWrite(PC8, val);  
diff --git a/Code/picocalc_keyboard/conf_app.h b/Code/picocalc_keyboard/conf_app.h
index 9c023eb..ae839f0 100644
--- a/Code/picocalc_keyboard/conf_app.h
+++ b/Code/picocalc_keyboard/conf_app.h
@@ -1,7 +1,9 @@
 #ifndef CONF_APP_H
 #define CONF_APP_H
 
-#define SLAVE_ADDRESS      0x1F
+#define BIOSVERSION      0x16
+
+#define SLAVE_ADDRESS    0x1F
 #define FIFO_SIZE        31
 
 #define INT_DURATION_MS  1
@@ -20,7 +22,8 @@
 
 
 #define LOW_BAT_VAL 20
-#define LCD_BACKLIGHT_STEP 10
+#define LCD_BACKLIGHT_STEP 16
+#define KBD_BACKLIGHT_STEP 32
 
 
 #define bitRead(value, bit) (((value) >> (bit)) & 0x01)
diff --git a/Code/picocalc_keyboard/keyboard.ino b/Code/picocalc_keyboard/keyboard.ino
index a7d57ff..f97c28f 100644
--- a/Code/picocalc_keyboard/keyboard.ino
+++ b/Code/picocalc_keyboard/keyboard.ino
@@ -176,7 +176,7 @@ static void transition_to(struct list_item * const p_item, const enum key_state
                 lcd_backlight_update(LCD_BACKLIGHT_STEP);
               }else if(chr == ' '){
                 //loop update keyboard backlight
-                kbd_backlight_update_offset();
+                kbd_backlight_update(KBD_BACKLIGHT_STEP);
               }else if(chr == 'B'){
                 show_bat_segs();
               }
diff --git a/Code/picocalc_keyboard/picocalc_keyboard.ino b/Code/picocalc_keyboard/picocalc_keyboard.ino
index 9292e86..63573bb 100644
--- a/Code/picocalc_keyboard/picocalc_keyboard.ino
+++ b/Code/picocalc_keyboard/picocalc_keyboard.ino
@@ -44,6 +44,12 @@ uint8_t js_bits=0xff;// c64 joystick bits
 
 unsigned long time_uptime_ms() { return millis(); }
 
+void nbDelay_ms(int n)
+{
+  unsigned long last_tick = millis();
+  while ( (millis() - last_tick) < n);
+}
+
 void lock_cb(bool caps_changed, bool num_changed) {
   bool do_int = false;
 
@@ -97,12 +103,17 @@ static void key_cb(char key, enum key_state state) {
   //Serial1.println(key);
 }
 
+long int receiveEventTick;
+long int requestEventTick;
+
 void receiveEvent(int howMany) {
   uint8_t rcv_data[2];  // max size 2, protocol defined
   uint8_t rcv_idx;
 
   if (Wire.available() < 1) return;
 
+  receiveEventTick = millis();
+
   rcv_idx = 0;
   while (Wire.available())  // loop through all but the last
   {
@@ -122,6 +133,10 @@ void receiveEvent(int howMany) {
   write_buffer_len = 2;
   
   switch (reg) {
+    case REG_ID_VER: {
+      write_buffer[0] = 0;
+      write_buffer[1] = BIOSVERSION;
+    } break;  
     case REG_ID_FIF: {
       const struct fifo_item item = fifo_dequeue();
       write_buffer[0] = (uint8_t)item.state;
@@ -130,7 +145,7 @@ void receiveEvent(int howMany) {
     case REG_ID_BKL: {
       if (is_write) {
         reg_set_value(REG_ID_BKL, rcv_data[1]);
-        lcd_backlight_update_reg();
+        lcd_backlight_update(0);
       }
       write_buffer[0] = reg;
       write_buffer[1] = reg_get_value(REG_ID_BKL);
@@ -197,10 +212,13 @@ void receiveEvent(int howMany) {
 
 //-this is after receiveEvent-------------------------------
 void requestEvent() {
+  requestEventTick = millis();
   if (write_buffer_len > 0 && write_buffer_len <= sizeof(write_buffer)) {
     Wire.write(write_buffer,write_buffer_len );
   } else {
-    Wire.write((uint8_t)0); // Send something minimal to avoid stalling
+	  write_buffer_len = 2;
+	  write_buffer[0]=0;
+	  write_buffer[1]=0;
   }
 }
 
@@ -461,7 +479,6 @@ void setup() {
   Wire.setSDA(PB9);
   Wire.setSCL(PB8);
   Wire.begin(SLAVE_ADDRESS);
-  Wire.setClock(10000);//It is important to set to 10Khz
   Wire.onReceive(receiveEvent);  // register event
   Wire.onRequest(requestEvent);
 
@@ -470,6 +487,7 @@ void setup() {
   bool result = PMU.begin(Wire2, AXP2101_SLAVE_ADDRESS, i2c_sda, i2c_scl);
 
   if (result == false) {
+    pmu_online = 0;
     Serial1.println("PMU is not online...");
   } else {
     pmu_online = 1;
@@ -523,7 +541,7 @@ void setup() {
 
   keyboard_init();
   keyboard_set_key_callback(key_cb);
-  lcd_backlight_update(-223);
+  lcd_backlight_update(0);
   
   digitalWrite(PA13, HIGH);
 
@@ -595,9 +613,31 @@ void check_hp_det(){
   head_phone_status = v;
   
 }
+
+void ResetI2CBus()
+{
+  Wire.end();
+  Wire.onReceive(NULL);  // register receive event
+  Wire.onRequest(NULL);  // register request event
+  nbDelay_ms(5);
+  Wire.setSDA(PB9);
+  Wire.setSCL(PB8);
+  receiveEventTick = millis();
+  requestEventTick = millis(); 
+  Wire.begin(SLAVE_ADDRESS);
+  Wire.onReceive(receiveEvent);  // register receive event
+  Wire.onRequest(requestEvent);  // register request event
+}
+
 void loop() {
   check_pmu_int();
   keyboard_process();
+  if (millis() > 10000) { 
+    if ( ((millis() - receiveEventTick) > 2500) || ((millis() - requestEventTick) > 2500)  )
+    {
+      ResetI2CBus();
+    }  
+  }
   check_hp_det();
-  delay(10);
+  nbDelay_ms(10);
 }