diff --git a/radio/src/gtests.cpp b/radio/src/gtests.cpp
index dbb8df463..22e53b688 100644
--- a/radio/src/gtests.cpp
+++ b/radio/src/gtests.cpp
@@ -42,7 +42,10 @@
 
 void doMixerCalculations();
 
-#define MODEL_RESET() memset(&g_model, 0, sizeof(g_model))
+#define MODEL_RESET() \
+  memset(&g_model, 0, sizeof(g_model)); \
+  extern bool s_mixer_first_run_done; \
+  s_mixer_first_run_done = false;
 
 #define MIXER_RESET() \
   memset(channelOutputs, 0, sizeof(channelOutputs)); \
@@ -62,6 +65,7 @@ uint16_t anaIn(uint8_t chan)
     return 0;
 }
 
+#if !defined(PCBTARANIS)
 TEST(Trims, greaterTrimLink)
 {
   MODEL_RESET();
@@ -88,6 +92,7 @@ TEST(Trims, infiniteChainedTrims)
   setTrimValue(3, 0, TRIM_EXTENDED_MAX+3); // link to FP2 trim
   EXPECT_EQ(getRawTrimValue(getTrimFlightPhase(0, 2), 0), 32);
 }
+#endif
 
 TEST(outdezNAtt, test_unsigned)
 {
@@ -565,16 +570,18 @@ TEST(Mixer, SlowOnSwitch)
   g_model.mixData[0].srcRaw = MIXSRC_MAX;
   g_model.mixData[0].weight = 100;
   g_model.mixData[0].swtch = SWSRC_THR;
-  g_model.mixData[0].speedUp = 10;
-  g_model.mixData[0].speedDown = 10;
+  g_model.mixData[0].speedUp = SLOW_STEP*5;
+  g_model.mixData[0].speedDown = SLOW_STEP*5;
 
+  s_mixer_first_run_done = true;
+  
   perOut(e_perout_mode_normal, 0);
   EXPECT_EQ(chans[0], 0);
 
   simuSetSwitch(0, 1);
   CHECK_SLOW_MOVEMENT(0, +1, 250);
 
-  simuSetSwitch(0, 0);
+  simuSetSwitch(0, -1);
   CHECK_SLOW_MOVEMENT(0, -1, 250);
 }
 
@@ -587,11 +594,12 @@ TEST(Mixer, SlowUpOnSwitch)
   g_model.mixData[0].srcRaw = MIXSRC_MAX;
   g_model.mixData[0].weight = 100;
   g_model.mixData[0].swtch = SWSRC_THR;
-  g_model.mixData[0].speedUp = 10;
+  g_model.mixData[0].speedUp = SLOW_STEP*5;
   g_model.mixData[0].speedDown = 0;
 
   simuSetSwitch(0, 0);
   perOut(e_perout_mode_normal, 0);
+  s_mixer_first_run_done = true;
   EXPECT_EQ(chans[0], 0);
 
   simuSetSwitch(0, 1);
@@ -605,20 +613,22 @@ TEST(Mixer, SlowUpOnSwitch)
   simuSetSwitch(0, 1);
   CHECK_SLOW_MOVEMENT(0, +1, 100);
 }
+#endif
 
 TEST(Mixer, SlowOnPhase)
 {
   MODEL_RESET();
   MIXER_RESET();
-  g_model.phaseData[1].swtch = SWSRC_THR;
+  g_model.phaseData[1].swtch = TR(SWSRC_THR, SWSRC_SA0);
   g_model.mixData[0].destCh = 0;
   g_model.mixData[0].mltpx = MLTPX_ADD;
   g_model.mixData[0].srcRaw = MIXSRC_MAX;
   g_model.mixData[0].weight = 100;
   g_model.mixData[0].phases = 0x2 + 0x4 + 0x8 + 0x10 /*only enabled in phase 0*/;
-  g_model.mixData[0].speedUp = 10;
-  g_model.mixData[0].speedDown = 10;
+  g_model.mixData[0].speedUp = SLOW_STEP*5;
+  g_model.mixData[0].speedDown = SLOW_STEP*5;
 
+  s_mixer_first_run_done = true;
   s_perout_flight_phase = 0;
   perOut(e_perout_mode_normal, 0);
   EXPECT_EQ(chans[0], 0);
@@ -629,20 +639,26 @@ TEST(Mixer, SlowOnPhase)
   CHECK_SLOW_MOVEMENT(0, -1, 250);
 }
 
+#if !defined(CPUARM)
 TEST(Mixer, SlowOnSwitchAndPhase)
 {
   MODEL_RESET();
   MIXER_RESET();
-  g_model.phaseData[1].swtch = SWSRC_THR;
+  g_model.phaseData[1].swtch = TR(SWSRC_THR, SWSRC_SA0);
   g_model.mixData[0].destCh = 0;
   g_model.mixData[0].mltpx = MLTPX_ADD;
   g_model.mixData[0].srcRaw = MIXSRC_MAX;
   g_model.mixData[0].weight = 100;
-  g_model.mixData[0].swtch = SWSRC_THR;
+  g_model.mixData[0].swtch = TR(SWSRC_THR, SWSRC_SA0);
+#if defined(CPUARM)
+  g_model.mixData[0].phases = 0x2 + 0x4 + 0x8 + 0x10 + 0x20 + 0x40 + 0x80 + 0x100 /*only enabled in phase 0*/;
+#else
   g_model.mixData[0].phases = 0x2 + 0x4 + 0x8 + 0x10 /*only enabled in phase 0*/;
-  g_model.mixData[0].speedUp = 10;
-  g_model.mixData[0].speedDown = 10;
+#endif
+  g_model.mixData[0].speedUp = SLOW_STEP*5;
+  g_model.mixData[0].speedDown = SLOW_STEP*5;
 
+  s_mixer_first_run_done = true;
   perOut(e_perout_mode_normal, 0);
   EXPECT_EQ(chans[0], 0);
 
@@ -650,25 +666,26 @@ TEST(Mixer, SlowOnSwitchAndPhase)
   s_perout_flight_phase = 0;
   CHECK_SLOW_MOVEMENT(0, +1, 250);
 
-  simuSetSwitch(0, 0);
+  simuSetSwitch(0, -1);
   s_perout_flight_phase = 1;
   CHECK_SLOW_MOVEMENT(0, -1, 250);
 }
 #endif
 
-#if !defined(PCBTARANIS)
 TEST(Mixer, SlowOnSwitchSource)
 {
   MODEL_RESET();
   MIXER_RESET();
   g_model.mixData[0].destCh = 0;
   g_model.mixData[0].mltpx = MLTPX_ADD;
-  g_model.mixData[0].srcRaw = MIXSRC_THR;
+  g_model.mixData[0].srcRaw = TR(MIXSRC_THR, MIXSRC_SA);
   g_model.mixData[0].weight = 100;
-  g_model.mixData[0].speedUp = 10;
-  g_model.mixData[0].speedDown = 10;
+  g_model.mixData[0].speedUp = SLOW_STEP*5;
+  g_model.mixData[0].speedDown = SLOW_STEP*5;
 
-  simuSetSwitch(0, 0);
+  s_mixer_first_run_done = true;
+
+  simuSetSwitch(0, -1);
   CHECK_SLOW_MOVEMENT(0, -1, 250);
   EXPECT_EQ(chans[0], -CHANNEL_MAX);
 
@@ -676,6 +693,22 @@ TEST(Mixer, SlowOnSwitchSource)
   CHECK_SLOW_MOVEMENT(0, +1, 500);
 }
 
+TEST(Mixer, SlowDisabledOnStartup)
+{
+  MODEL_RESET();
+  MIXER_RESET();
+  g_model.mixData[0].destCh = 0;
+  g_model.mixData[0].mltpx = MLTPX_ADD;
+  g_model.mixData[0].srcRaw = MIXSRC_MAX;
+  g_model.mixData[0].weight = 100;
+  g_model.mixData[0].speedUp = SLOW_STEP*5;
+  g_model.mixData[0].speedDown = SLOW_STEP*5;
+
+  perOut(e_perout_mode_normal, 0);
+  EXPECT_EQ(chans[0], CHANNEL_MAX);
+}
+
+#if !defined(PCBTARANIS)
 TEST(Mixer, SlowAndDelayOnReplace3POSSource)
 {
   MODEL_RESET();
@@ -685,9 +718,11 @@ TEST(Mixer, SlowAndDelayOnReplace3POSSource)
   g_model.mixData[0].srcRaw = MIXSRC_3POS;
   g_model.mixData[0].weight = 100;
   g_model.mixData[0].delayUp = 10;
-  g_model.mixData[0].speedUp = 10;
-  g_model.mixData[0].speedDown = 10;
+  g_model.mixData[0].speedUp = SLOW_STEP*5;
+  g_model.mixData[0].speedDown = SLOW_STEP*5;
 
+  s_mixer_first_run_done = true;
+  
   simuSetSwitch(3, -1);
   CHECK_SLOW_MOVEMENT(0, -1, 250);
   EXPECT_EQ(chans[0], -CHANNEL_MAX);
@@ -717,7 +752,7 @@ TEST(Mixer, SlowOnSwitchReplace)
   g_model.mixData[1].srcRaw = MIXSRC_MAX;
   g_model.mixData[1].weight = 100;
   g_model.mixData[1].swtch = SWSRC_THR;
-  g_model.mixData[1].speedDown = 10;
+  g_model.mixData[1].speedDown = SLOW_STEP*5;
 
   simuSetSwitch(0, 0);
   perOut(e_perout_mode_normal, 1);
@@ -745,16 +780,19 @@ TEST(Mixer, NoTrimOnInactiveMix)
   g_model.mixData[0].srcRaw = MIXSRC_Thr;
   g_model.mixData[0].weight = 100;
   g_model.mixData[0].swtch = SWSRC_THR;
-  g_model.mixData[0].speedUp = 10;
-  g_model.mixData[0].speedDown = 10;
+  g_model.mixData[0].speedUp = SLOW_STEP*5;
+  g_model.mixData[0].speedDown = SLOW_STEP*5;
   setTrimValue(0, 2, 256);
 
+  s_mixer_first_run_done = true;
+
   simuSetSwitch(0, 1);
   CHECK_SLOW_MOVEMENT(0, 1, 100);
 
-  simuSetSwitch(0, 0);
+  simuSetSwitch(0, -1);
   CHECK_SLOW_MOVEMENT(0, -1, 100);
 }
+#endif
 
 TEST(Mixer, SlowOnMultiply)
 {
@@ -768,20 +806,21 @@ TEST(Mixer, SlowOnMultiply)
   g_model.mixData[1].mltpx = MLTPX_MUL;
   g_model.mixData[1].srcRaw = MIXSRC_MAX;
   g_model.mixData[1].weight = 100;
-  g_model.mixData[1].swtch = SWSRC_THR;
-  g_model.mixData[1].speedUp = 10;
-  g_model.mixData[1].speedDown = 10;
+  g_model.mixData[1].swtch = TR(SWSRC_THR, SWSRC_SA0);
+  g_model.mixData[1].speedUp = SLOW_STEP*5;
+  g_model.mixData[1].speedDown = SLOW_STEP*5;
+
+  s_mixer_first_run_done = true;
 
   simuSetSwitch(0, 1);
   CHECK_SLOW_MOVEMENT(0, 1, 250);
 
-  simuSetSwitch(0, 0);
+  simuSetSwitch(0, -1);
   CHECK_NO_MOVEMENT(0, CHANNEL_MAX, 250);
 
   simuSetSwitch(0, 1);
   CHECK_NO_MOVEMENT(0, CHANNEL_MAX, 250);
 }
-#endif
 
 TEST(Curves, LinearIntpol)
 {
diff --git a/radio/src/opentx.cpp b/radio/src/opentx.cpp
index b4b744351..8f3d2d742 100644
--- a/radio/src/opentx.cpp
+++ b/radio/src/opentx.cpp
@@ -2983,6 +2983,8 @@ void resetTimer(uint8_t idx)
   timerState.val_10ms = 0 ;
 }
 
+bool s_mixer_first_run_done = false;
+
 void resetAll()
 {
   static bool firstReset = true;
@@ -3001,6 +3003,7 @@ void resetAll()
   }
 
   s_last_switch_value = 0;
+  s_mixer_first_run_done = false;
 
   SKIP_AUTOMATIC_PROMPTS();
 
@@ -3855,21 +3858,21 @@ void perOut(uint8_t mode, uint8_t tick10ms)
           // the unit of the stored value is the value from md->speedUp or md->speedDown divide SLOW_STEP seconds; e.g. value 4 means 4/SLOW_STEP = 2 seconds for CPU64
           // because we get a tick each 10msec, we need 100 ticks for one second
           // the value in md->speedXXX gives the time it should take to do a full movement from -100 to 100 therefore 200%. This equals 2048 in recalculated internal range
-          if (tick10ms) {
+          if (tick10ms || !s_mixer_first_run_done) {
             // only if already time is passed add or substract a value according the speed configured
             int32_t rate = (int32_t) tick10ms << (DEL_MULT_SHIFT+11);  // = DEL_MULT*2048*tick10ms
             // rate equals a full range for one second; if less time is passed rate is accordingly smaller
             // if one second passed, rate would be 2048 (full motion)*256(recalculated weight)*100(100 ticks needed for one second)
             int32_t currentValue = ((int32_t) v<<DEL_MULT_SHIFT);
             if (diff > 0) {
-              if (md->speedUp > 0) {
+              if (s_mixer_first_run_done && md->speedUp > 0) {
                 // if a speed upwards is defined recalculate the new value according configured speed; the higher the speed the smaller the add value is
                 int32_t newValue = tact+rate/((int16_t)(100/SLOW_STEP)*md->speedUp);
                 if (newValue<currentValue) currentValue = newValue; // Endposition; prevent toggling around the destination
               }
             }
             else {  // if is <0 because ==0 is not possible
-              if (md->speedDown > 0) {
+              if (s_mixer_first_run_done && md->speedDown > 0) {
                 // see explanation in speedUp
                 int32_t newValue = tact-rate/((int16_t)(100/SLOW_STEP)*md->speedDown);
                 if (newValue>currentValue) currentValue = newValue; // Endposition; prevent toggling around the destination
@@ -4092,6 +4095,8 @@ void doMixerCalculations()
     perOut(e_perout_mode_normal, tick10ms);
   }
 
+  s_mixer_first_run_done = true;
+
   //========== FUNCTIONS ===============
   // must be done after mixing because some functions use the inputs/channels values
   // must be done before limits because of the applyLimit function: it checks for safety switches which would be not initialized otherwise
diff --git a/radio/src/simpgmspace.cpp b/radio/src/simpgmspace.cpp
index b00c96be7..bd86354f0 100644
--- a/radio/src/simpgmspace.cpp
+++ b/radio/src/simpgmspace.cpp
@@ -101,12 +101,12 @@ sem_t *eeprom_write_sem;
 #if defined(PCBTARANIS)
 #define SWITCH_CASE(swtch, pin, mask) \
     case swtch: \
-      if (state) pin &= ~(mask); else pin |= (mask); \
+      if (state > 0) pin &= ~(mask); else pin |= (mask); \
       break;
 #else
 #define SWITCH_CASE(swtch, pin, mask) \
     case swtch: \
-      if (state) pin |= (mask); else pin &= ~(mask); \
+      if (state > 0) pin |= (mask); else pin &= ~(mask); \
       break;
 #endif
 #define SWITCH_3_CASE(swtch, pin1, pin2, mask1, mask2) \
@@ -116,13 +116,13 @@ sem_t *eeprom_write_sem;
       break;
 #define KEY_CASE(key, pin, mask) \
     case key: \
-      if (state) pin &= ~mask; else pin |= mask;\
+      if (state > 0) pin &= ~mask; else pin |= mask;\
       break;
 #define TRIM_CASE KEY_CASE
 #else
 #define SWITCH_CASE(swtch, pin, mask) \
     case swtch: \
-      if (state) pin &= ~(mask); else pin |= (mask); \
+      if (state > 0) pin &= ~(mask); else pin |= (mask); \
       break;
 #define SWITCH_3_CASE(swtch, pin1, pin2, mask1, mask2) \
     case swtch: \
@@ -131,7 +131,7 @@ sem_t *eeprom_write_sem;
       break;
 #define KEY_CASE(key, pin, mask) \
     case key: \
-      if (state) pin |= (mask); else pin &= ~(mask);\
+      if (state > 0) pin |= (mask); else pin &= ~(mask);\
       break;
 #define TRIM_CASE KEY_CASE
 #endif