diff --git a/radio/src/simu.cpp b/radio/src/simu.cpp
index 5cf6e578a..32f4451af 100644
--- a/radio/src/simu.cpp
+++ b/radio/src/simu.cpp
@@ -74,6 +74,7 @@ class OpenTxSim: public FXMainWindow
     void doEvents();
     void refreshDisplay();
     void setPixel(int x, int y, FXColor color);
+    void fsLedRGB(uint8_t idx, uint32_t color);
 
   private:
     FXImage * bmp;
@@ -82,6 +83,9 @@ class OpenTxSim: public FXMainWindow
   public:
     FXSlider * sliders[MAX_STICKS];
     FXKnob * knobs[MAX_POTS];
+#if defined(FUNCTION_SWITCHES)
+    FXButton * fctButtons[NUM_FUNCTIONS_SWITCHES] = {0};
+#endif
 };
 
 // Message Map
@@ -109,6 +113,9 @@ OpenTxSim::OpenTxSim(FXApp* a):
 #endif
 
   FXHorizontalFrame * hf11 = new FXHorizontalFrame(this, LAYOUT_CENTER_X);
+#if defined(FUNCTION_SWITCHES)
+  FXHorizontalFrame * hf12 = new FXHorizontalFrame(this, LAYOUT_CENTER_X);
+#endif
   FXHorizontalFrame * hf1 = new FXHorizontalFrame(this, LAYOUT_FILL_X);
 
   //rh lv rv lh
@@ -142,7 +149,7 @@ OpenTxSim::OpenTxSim(FXApp* a):
     knobs[i]->setRange(0, 4095);
     knobs[i]->setValue(2047);
 
-#if defined(PCBHORUS)
+#if defined(PCBHORUS) && !defined(FUNCTION_SWITCHES)
     if (i == 1) {  // 6-pos switch
       knobs[i]->setIncrement(4095 / 5);
       knobs[i]->setTickDelta(4095 / 5);
@@ -152,6 +159,14 @@ OpenTxSim::OpenTxSim(FXApp* a):
 #endif
   }
 
+#if defined(FUNCTION_SWITCHES)
+  for(int i = 0; i < NUM_FUNCTIONS_SWITCHES; ++i)
+  {
+    fctButtons[i] = new FXButton(hf12, "     ", nullptr, nullptr, 123, LAYOUT_LEFT|BUTTON_NORMAL, 0, 0, 50, 0, 15, 15);
+    fctButtons[i]->setBorderColor(FXColor(0));
+  }
+#endif
+
   bmf = new FXImageFrame(this, bmp);
   bmf->enable();
   bmf->setTarget(this);
@@ -465,6 +480,19 @@ void OpenTxSim::updateKeysAndSwitches(bool start)
     SWITCH_KEY(Q, 16, 3);
     SWITCH_KEY(R, 17, 3);
   #endif
+
+#if defined(FUNCTION_SWITCHES)
+    for(int i = 0; i < NUM_FUNCTIONS_SWITCHES; ++i)
+    {
+      int8_t newState = -1;
+      if(fctButtons[i]->getState()==STATE_DOWN)
+      {
+        newState = 1;
+      }
+
+      simuSetSwitch(switchGetMaxSwitches() + i, newState);
+    }
+#endif
 }
 
 extern volatile rotenc_t rotencValue;
@@ -596,6 +624,15 @@ void OpenTxSim::refreshDisplay()
   }
 }
 
+void OpenTxSim::fsLedRGB(uint8_t idx, uint32_t color)
+{
+#if defined(FUNCTION_SWITCHES)
+  uint32_t col = (color&0x00FF0000)>>16 | (color&0x0000FF00) | (color&0x000000FF)<<16;
+  fctButtons[idx]->setBaseColor(col);
+  fctButtons[idx]->setBackColor(col);
+#endif
+}
+
 OpenTxSim * opentxSim;
 
 void doFxEvents()
@@ -671,3 +708,19 @@ void createBitmap(int index, uint16_t *data, int x, int y, int w, int h)
 {
   opentxSim->createBitmap(index, data, x, y, w, h);
 }
+
+
+void fsLedRGB(uint8_t idx, uint32_t color)
+{
+  opentxSim->fsLedRGB(idx, color);
+}
+
+void fsLedOn(uint8_t idx)
+{
+  opentxSim->fsLedRGB(idx, 0x00ffffff);
+}
+
+void fsLedOff(uint8_t idx)
+{
+  opentxSim->fsLedRGB(idx, 0);
+}
diff --git a/radio/src/targets/simu/led_driver.cpp b/radio/src/targets/simu/led_driver.cpp
index c759796b4..c921a811d 100644
--- a/radio/src/targets/simu/led_driver.cpp
+++ b/radio/src/targets/simu/led_driver.cpp
@@ -28,9 +28,9 @@ void ledRed() {}
 void ledGreen() {}
 void ledBlue() {}
 void ledOff() {}
-void fsLedOn(uint8_t) {}
-void fsLedOff(uint8_t) {}
-void fsLedRGB(uint8_t, uint32_t) {}
+__attribute__((weak)) void fsLedOn(uint8_t) {}
+__attribute__((weak)) void fsLedOff(uint8_t) {}
+__attribute__((weak)) void fsLedRGB(uint8_t, uint32_t) {}
 bool fsLedState(uint8_t) { return false;}
 void rgbSetLedColor(unsigned char, unsigned char, unsigned char, unsigned char) {}
 void rgbLedColorApply() {}
diff --git a/radio/src/targets/simu/switch_driver.cpp b/radio/src/targets/simu/switch_driver.cpp
index 86566162d..b4b9a822d 100644
--- a/radio/src/targets/simu/switch_driver.cpp
+++ b/radio/src/targets/simu/switch_driver.cpp
@@ -66,8 +66,8 @@ SwitchHwPos boardSwitchGetPosition(SwitchCategory cat, uint8_t idx)
   idx = get_switch_index(cat, idx);
 
 #if defined(FUNCTION_SWITCHES)
-  if (IS_SWITCH_FS(idx + n_switches)) {
-    if (bfSingleBitGet(functionSwitchFunctionState, idx))
+  if (IS_SWITCH_FS(idx)) {
+    if (bfSingleBitGet(functionSwitchFunctionState, idx - n_switches))
       return SWITCH_HW_DOWN;
   }
 #endif