diff --git a/radio/src/dataconstants.h b/radio/src/dataconstants.h
index 79a740723..c619d800e 100644
--- a/radio/src/dataconstants.h
+++ b/radio/src/dataconstants.h
@@ -660,12 +660,14 @@ enum HatsMode {
   HATSMODE_GLOBAL
 };
 
+#if defined(STM32F2) || defined(STM32F4)
 enum UartSampleModes {
   UART_SAMPLE_MODE_NORMAL = 0,
   UART_SAMPLE_MODE_ONEBIT,
 
   UART_SAMPLE_MODE_MAX SKIP = UART_SAMPLE_MODE_ONEBIT
 };
+#endif
 
 // PXX2 constants
 #define PXX2_LEN_REGISTRATION_ID            8
diff --git a/radio/src/datastructs_private.h b/radio/src/datastructs_private.h
index 3c9cd2951..c7aeb341d 100644
--- a/radio/src/datastructs_private.h
+++ b/radio/src/datastructs_private.h
@@ -1072,7 +1072,9 @@ PACK(struct RadioData {
   CUST_ATTR(rotEncDirection, r_rotEncDirection, nullptr);
   NOBACKUP(uint8_t  rotEncMode:3);
 
+#if defined(STM32F2) || defined(STM32F4)
   NOBACKUP(int8_t   uartSampleMode:2); // See UartSampleModes
+#endif
 
 #if defined(STICK_DEAD_ZONE)
   NOBACKUP(uint8_t  stickDeadZone:3);
diff --git a/radio/src/gui/colorlcd/radio/hw_extmodule.cpp b/radio/src/gui/colorlcd/radio/hw_extmodule.cpp
index b5cc414e1..c44193e8f 100644
--- a/radio/src/gui/colorlcd/radio/hw_extmodule.cpp
+++ b/radio/src/gui/colorlcd/radio/hw_extmodule.cpp
@@ -25,6 +25,7 @@
 
 #define SET_DIRTY() storageDirty(EE_GENERAL)
 
+#if defined(STM32F4)
 ExternalModuleWindow::ExternalModuleWindow(Window *parent, FlexGridLayout& grid)
 {
   auto line = parent->newLine(grid);
@@ -39,3 +40,4 @@ ExternalModuleWindow::ExternalModuleWindow(Window *parent, FlexGridLayout& grid)
                restartModule(EXTERNAL_MODULE);
              });
 }
+#endif
diff --git a/radio/src/gui/colorlcd/radio/radio_hardware.cpp b/radio/src/gui/colorlcd/radio/radio_hardware.cpp
index 27bb12569..0c924f6cc 100644
--- a/radio/src/gui/colorlcd/radio/radio_hardware.cpp
+++ b/radio/src/gui/colorlcd/radio/radio_hardware.cpp
@@ -172,7 +172,7 @@ void RadioHardwarePage::build(Window* window)
   new InternalModuleWindow(window, grid);
 #endif
 
-#if defined(HARDWARE_EXTERNAL_MODULE)
+#if defined(HARDWARE_EXTERNAL_MODULE) && defined(STM32F4)
   new Subtitle(window, STR_EXTERNALRF);
   new ExternalModuleWindow(window, grid);
 #endif
diff --git a/radio/src/gui/common/stdlcd/radio_hardware.cpp b/radio/src/gui/common/stdlcd/radio_hardware.cpp
index 7c602ee24..1a7f5dd9d 100644
--- a/radio/src/gui/common/stdlcd/radio_hardware.cpp
+++ b/radio/src/gui/common/stdlcd/radio_hardware.cpp
@@ -314,7 +314,7 @@ static void _init_menu_tab_array(uint8_t* tab, size_t len)
   memset((void*)&tab[ITEM_RADIO_HARDWARE_LABEL_INTERNAL_MODULE], HIDDEN_ROW, 3);
 #endif
 
-#if defined(HARDWARE_EXTERNAL_MODULE)
+#if defined(HARDWARE_EXTERNAL_MODULE) && (defined(STM32F2) || defined(STM32F4))
   tab[ITEM_RADIO_HARDWARE_SERIAL_SAMPLE_MODE] = 0;
 #else
   tab[ITEM_RADIO_HARDWARE_SERIAL_SAMPLE_MODE] = HIDDEN_ROW;
@@ -502,12 +502,14 @@ void menuRadioHardware(event_t event)
         }
         break;
 
+#if defined(STM32F2) || defined(STM32F4)
       case ITEM_RADIO_HARDWARE_SERIAL_SAMPLE_MODE:
         g_eeGeneral.uartSampleMode = editChoice(HW_SETTINGS_COLUMN2, y, STR_SAMPLE_MODE, STR_SAMPLE_MODES, g_eeGeneral.uartSampleMode, 0, UART_SAMPLE_MODE_MAX, attr, event);
         if (attr && checkIncDec_Ret) {
           restartModule(EXTERNAL_MODULE);
         }
         break;
+#endif
 
 #if defined(BLUETOOTH)
       case ITEM_RADIO_HARDWARE_BLUETOOTH_MODE:
diff --git a/radio/src/hal/module_port.cpp b/radio/src/hal/module_port.cpp
index 948054c52..81ce63cef 100644
--- a/radio/src/hal/module_port.cpp
+++ b/radio/src/hal/module_port.cpp
@@ -69,10 +69,12 @@ static bool _init_serial_driver(etx_module_driver_t* d, const etx_module_port_t*
 
   // S.PORT specific HW settings
   if (port->port == ETX_MOD_PORT_SPORT && params->baudrate >= 400000) {
+#if defined(STM32F2) || defined(STM32F4)
     // one-bit
     if (g_eeGeneral.uartSampleMode == UART_SAMPLE_MODE_ONEBIT) {
       if (drv->setHWOption) drv->setHWOption(d->ctx, ETX_HWOption_ONEBIT);
     }
+#endif
   }
 
   // setup polarity
diff --git a/radio/src/storage/yaml/yaml_datastructs_pa01.cpp b/radio/src/storage/yaml/yaml_datastructs_pa01.cpp
index ff953a026..4cf06b8c7 100644
--- a/radio/src/storage/yaml/yaml_datastructs_pa01.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_pa01.cpp
@@ -407,7 +407,6 @@ static const struct YamlNode struct_RadioData[] = {
   YAML_STRING("ownerRegistrationID", 8),
   YAML_CUSTOM("rotEncDirection",r_rotEncDirection,nullptr),
   YAML_UNSIGNED( "rotEncMode", 3 ),
-  YAML_SIGNED( "uartSampleMode", 2 ),
   YAML_UNSIGNED( "stickDeadZone", 3 ),
   YAML_SIGNED( "imuMax", 8 ),
   YAML_SIGNED( "imuOffset", 8 ),
diff --git a/radio/src/storage/yaml/yaml_datastructs_st16.cpp b/radio/src/storage/yaml/yaml_datastructs_st16.cpp
index 01d8a3f61..3255a773f 100644
--- a/radio/src/storage/yaml/yaml_datastructs_st16.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_st16.cpp
@@ -407,7 +407,6 @@ static const struct YamlNode struct_RadioData[] = {
   YAML_STRING("ownerRegistrationID", 8),
   YAML_CUSTOM("rotEncDirection",r_rotEncDirection,nullptr),
   YAML_UNSIGNED( "rotEncMode", 3 ),
-  YAML_SIGNED( "uartSampleMode", 2 ),
   YAML_UNSIGNED( "stickDeadZone", 3 ),
   YAML_SIGNED( "imuMax", 8 ),
   YAML_SIGNED( "imuOffset", 8 ),
diff --git a/radio/src/storage/yaml/yaml_datastructs_t15pro.cpp b/radio/src/storage/yaml/yaml_datastructs_t15pro.cpp
index 01d8a3f61..3255a773f 100644
--- a/radio/src/storage/yaml/yaml_datastructs_t15pro.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_t15pro.cpp
@@ -407,7 +407,6 @@ static const struct YamlNode struct_RadioData[] = {
   YAML_STRING("ownerRegistrationID", 8),
   YAML_CUSTOM("rotEncDirection",r_rotEncDirection,nullptr),
   YAML_UNSIGNED( "rotEncMode", 3 ),
-  YAML_SIGNED( "uartSampleMode", 2 ),
   YAML_UNSIGNED( "stickDeadZone", 3 ),
   YAML_SIGNED( "imuMax", 8 ),
   YAML_SIGNED( "imuOffset", 8 ),
diff --git a/radio/src/storage/yaml/yaml_datastructs_tx15.cpp b/radio/src/storage/yaml/yaml_datastructs_tx15.cpp
index 01d8a3f61..3255a773f 100644
--- a/radio/src/storage/yaml/yaml_datastructs_tx15.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_tx15.cpp
@@ -407,7 +407,6 @@ static const struct YamlNode struct_RadioData[] = {
   YAML_STRING("ownerRegistrationID", 8),
   YAML_CUSTOM("rotEncDirection",r_rotEncDirection,nullptr),
   YAML_UNSIGNED( "rotEncMode", 3 ),
-  YAML_SIGNED( "uartSampleMode", 2 ),
   YAML_UNSIGNED( "stickDeadZone", 3 ),
   YAML_SIGNED( "imuMax", 8 ),
   YAML_SIGNED( "imuOffset", 8 ),