diff --git a/radio/src/opentx.cpp b/radio/src/opentx.cpp
index 5590014a4..8f6ea9769 100644
--- a/radio/src/opentx.cpp
+++ b/radio/src/opentx.cpp
@@ -135,27 +135,41 @@ void per10ms()
 #if defined(ROTARY_ENCODER_NAVIGATION)
   if (IS_ROTARY_ENCODER_NAVIGATION_ENABLE()) {
     static rotenc_t rePreviousValue;
+    static bool cw = false;
     rotenc_t reNewValue = (ROTARY_ENCODER_NAVIGATION_VALUE / ROTARY_ENCODER_GRANULARITY);
-    int8_t scrollRE = reNewValue - rePreviousValue;
+    rotenc_t scrollRE = reNewValue - rePreviousValue;
     if (scrollRE) {
+      static uint32_t lastEvent;
       rePreviousValue = reNewValue;
-      putEvent(scrollRE < 0 ? EVT_ROTARY_LEFT : EVT_ROTARY_RIGHT);
-    }
+
+      bool new_cw = (scrollRE < 0) ? false : true;
+      if ((g_tmr10ms - lastEvent >= 10) || (cw == new_cw)) { // 100ms
+
+        putEvent(new_cw ? EVT_ROTARY_RIGHT : EVT_ROTARY_LEFT);
+
 #if defined(CPUARM)
-    // rotary encoder navigation speed (acceleration) detection/calculation
-    if (scrollRE) {
-      static uint32_t lastTick = 0;
-      static uint32_t delay = 0;
-      delay = (((get_tmr10ms() - lastTick) << 3) + delay) >> 1;   // Modified moving average filter used for smoother change of speed
-      lastTick = get_tmr10ms();
-      if (delay < ROTENC_DELAY_HIGHSPEED)
-        rotencSpeed = ROTENC_HIGHSPEED;
-      else if (delay < ROTENC_DELAY_MIDSPEED)
-        rotencSpeed = ROTENC_MIDSPEED;
-      else
-        rotencSpeed = ROTENC_LOWSPEED;
-    }
+        // rotary encoder navigation speed (acceleration) detection/calculation
+        static uint32_t delay = 2*ROTENC_DELAY_MIDSPEED;
+
+        if (new_cw == cw) {
+          // Modified moving average filter used for smoother change of speed
+          delay = (((g_tmr10ms - lastEvent) << 3) + delay) >> 1;
+        }
+        else {
+          delay = 2*ROTENC_DELAY_MIDSPEED;
+        }
+
+        if (delay < ROTENC_DELAY_HIGHSPEED)
+          rotencSpeed = ROTENC_HIGHSPEED;
+        else if (delay < ROTENC_DELAY_MIDSPEED)
+          rotencSpeed = ROTENC_MIDSPEED;
+        else
+          rotencSpeed = ROTENC_LOWSPEED;
 #endif
+        cw = new_cw;
+        lastEvent = g_tmr10ms;
+      }
+    }
   }
 #endif
 
diff --git a/radio/src/opentx.h b/radio/src/opentx.h
index 59bcf05ae..1ae35521d 100644
--- a/radio/src/opentx.h
+++ b/radio/src/opentx.h
@@ -769,6 +769,8 @@ int getTrimValue(uint8_t phase, uint8_t idx);
   #define ROTARY_ENCODER_GRANULARITY (1)
 #elif defined(PCBSKY9X)
   #define ROTARY_ENCODER_GRANULARITY (2 << g_eeGeneral.rotarySteps)
+#elif defined(PCBHORUS)
+  #define ROTARY_ENCODER_GRANULARITY (1)
 #else
   #define ROTARY_ENCODER_GRANULARITY (2)
 #endif
diff --git a/radio/src/targets/horus/keys_driver.cpp b/radio/src/targets/horus/keys_driver.cpp
index ce843e0ca..1a4b96830 100644
--- a/radio/src/targets/horus/keys_driver.cpp
+++ b/radio/src/targets/horus/keys_driver.cpp
@@ -20,7 +20,63 @@
 
 #include "opentx.h"
 
-uint32_t rotencPosition;
+/*
+ * Rotary encoder handling based on state table:
+ * Copyright (C) by Ben Buxton
+ * 
+ * This includes the state table definition bellow
+ * as well as the implementation of checkRotaryEncoder().
+ * 
+ * The below state table has, for each state (row), the new state
+ * to set based on the next encoder output. From left to right in,
+ * the table, the encoder outputs are 00, 01, 10, 11, and the value
+ * in that position is the new state to set.
+ */
+
+#define R_START 0x0
+#define DIR_CW  0x10
+#define DIR_CCW 0x20
+
+// Use the half-step state table (emits a code at 00 and 11)
+#define R_CCW_BEGIN 0x1
+#define R_CW_BEGIN 0x2
+#define R_START_M 0x3
+#define R_CW_BEGIN_M 0x4
+#define R_CCW_BEGIN_M 0x5
+const unsigned char rotenc_table[6][4] = {
+  // R_START (00)
+  {R_START_M,            R_CW_BEGIN,     R_CCW_BEGIN,  R_START},
+  // R_CCW_BEGIN
+  {R_START_M | DIR_CCW, R_START,        R_CCW_BEGIN,  R_START},
+  // R_CW_BEGIN
+  {R_START_M | DIR_CW,  R_CW_BEGIN,     R_START,      R_START},
+  // R_START_M (11)
+  {R_START_M,            R_CCW_BEGIN_M,  R_CW_BEGIN_M, R_START},
+  // R_CW_BEGIN_M
+  {R_START_M,            R_START_M,      R_CW_BEGIN_M, R_START | DIR_CW},
+  // R_CCW_BEGIN_M
+  {R_START_M,            R_CCW_BEGIN_M,  R_START_M,    R_START | DIR_CCW},
+};
+
+void checkRotaryEncoder()
+{
+  static uint8_t  state = 0;
+  uint32_t pins = ROTARY_ENCODER_POSITION();
+  
+  state = rotenc_table[state & 0x0F][pins];
+  if ((state & 0x30) && !keyState(KEY_ENTER)) {
+    if ((state & 0x30) == DIR_CW) {
+      --rotencValue[0];
+    }
+    else {
+      ++rotencValue[0];
+    }
+  }
+}
+
+/*
+ * End of the rotary encoder handler code
+ */
 
 uint32_t readKeys()
 {
@@ -91,20 +147,6 @@ uint8_t keyDown()
   return readKeys();
 }
 
-void checkRotaryEncoder()
-{
-  uint32_t newpos = ROTARY_ENCODER_POSITION();
-  if (newpos != rotencPosition && !keyState(KEY_ENTER)) {
-    if ((rotencPosition & 0x01) ^ ((newpos & 0x02) >> 1)) {
-      --rotencValue[0];
-    }
-    else {
-      ++rotencValue[0];
-    }
-    rotencPosition = newpos;
-  }
-}
-
 /* TODO common to ARM */
 void readKeysAndTrims()
 {
@@ -239,6 +281,4 @@ void keysInit()
 
   GPIO_InitStructure.GPIO_Pin = KEYS_GPIOJ_PINS;
   GPIO_Init(GPIOJ, &GPIO_InitStructure);
-
-  rotencPosition = ROTARY_ENCODER_POSITION();
 }