diff --git a/src/myeeprom.h b/src/myeeprom.h
index ddeb65d29..8603c5f16 100644
--- a/src/myeeprom.h
+++ b/src/myeeprom.h
@@ -388,11 +388,8 @@ PACK(typedef struct t_SwashRingData { // Swash Ring data
 #if defined(PCBV4)
 #if defined(MOD_EXTRA_ROTARY_ENCODERS)
 #define NUM_EXTRA_ROTARY_ENCODERS 3
-#define VPOT_STEP       5
-#define VPOT_MAX        1000
-#define VPOT_MIN        -VPOT_MAX
 #else //MOD_EXTRA_ROTARY_ENCODERS
-#define NUM_EXTRA_ROTARY_ENCODERS 3
+#define NUM_EXTRA_ROTARY_ENCODERS 0
 #endif //MOD_EXTRA_ROTARY_ENCODERS
 #define NUM_ROTARY_ENCODERS (2+NUM_EXTRA_ROTARY_ENCODERS)
 #define ROTARY_ENCODER_MAX  1024
diff --git a/src/open9x.cpp b/src/open9x.cpp
index ba8c27d77..0d229d534 100644
--- a/src/open9x.cpp
+++ b/src/open9x.cpp
@@ -2189,6 +2189,42 @@ ISR(TIMER3_CAPT_vect) // G: High frequency noise can cause stack overflo with IS
 #endif
 }
 
+#if defined (PCBV4) & defined(MOD_EXTRA_ROTARY_ENCODERS)
+
+uint8_t vpotToChange = 0;
+uint8_t vpot_mod_state = 0;
+
+ISR(USART2_RX_vect)
+{
+	//receive data from extension board
+	//bit 9 = 1 mean encoder number, following byte with bit 9 = 0 is increment value
+  /* Get status and 9th bit, then data */
+  /* from buffer */
+  //uint8_t status = UCSR2A;
+  uint16_t resh = UCSR2B;
+  uint16_t resl = UDR2;
+  uint16_t res = 0;
+  //if ( status & (1<<FEn)|(1<<DORn)|(1<<UPEn) )
+  
+  /* Filter the 9th bit, then return */
+  resh = (resh >> 1) & 0x01;
+  res = ((resh << 8) | resl);	
+  if((res & 0x100) == 0x100){
+	  vpotToChange = res & 0xff;
+	  vpot_mod_state = 1;
+  }else{
+	  if(vpot_mod_state & (vpotToChange>0) & (vpotToChange<=NUM_EXTRA_ROTARY_ENCODERS))
+	  {
+      int8_t vpot_inc = res & 0xff;
+		  if(vpot_inc){
+			  incRotaryEncoder(NUM_ROTARY_ENCODERS-NUM_EXTRA_ROTARY_ENCODERS+vpotToChange-1, vpot_inc);
+		  }	  
+	    vpot_mod_state = 0;
+	  }
+  }
+}
+#endif //MOD_EXTRA_ROTARY_ENCODERS
+
 extern uint16_t g_timeMain;
 
 /*
@@ -2546,6 +2582,19 @@ int main(void)
    */
   OCR4A = 0x7d;
   TCCR4B = (1 << WGM42) | (3<<CS40); // CTC OCR1A, 16MHz / 64 (4us ticks)
+
+#ifdef MOD_EXTRA_ROTARY_ENCODERS
+  //configure uart2 here
+  DDRH &= ~(1 << 0);
+  PORTH &= ~(1 << 0);
+  #define MOD_EXTRA_ROTARY_ENCODERS_USART_BAUD 9600UL
+  UBRR2 = F_CPU/(16*MOD_EXTRA_ROTARY_ENCODERS_USART_BAUD)-1;
+  //9 bit mode
+  UCSR2C = (1<<USBS2)|(3<<UCSZ20);
+  UCSR2B = (1<<RXEN2)|(0<<TXEN2)|(1<<UCSZ22);
+  UCSR2B |= 1 << RXCIE2; //enable interrupt on rx
+#endif //MOD_EXTRA_ROTARY_ENCODERS
+  
 #endif
 
 #if defined(PCBARM)