diff --git a/ArduPlane/ReleaseNotes.txt b/ArduPlane/ReleaseNotes.txt
index 8fbec26bd3..583fb4d0b3 100644
--- a/ArduPlane/ReleaseNotes.txt
+++ b/ArduPlane/ReleaseNotes.txt
@@ -1,3 +1,13 @@
+Release 5.0.1 20th Nov 2023
+---------------------------
+Changes since 4.3.8:
+ - AP_BattMonitor: Addition of AD7091R5 ADC I2C Read Driver #23564
+ - AP_Compass: Add in QMC5883P driver #25230
+ - Carbonix PR - AP_BattMonitor: Add in reventech fuel level driver #25219
+ - WIP: Hirth Engine Integration #21805
+ - feature/OV3-1018-enable-ardupilot-apd-implementation-in-hwdef
+ 
+
 Release 4.3.8 24th August 2023
 ------------------------------
 
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/CarbonixF405/hwdef-bl.dat b/libraries/AP_HAL_ChibiOS/hwdef/CarbonixF405/hwdef-bl.dat
index c9b65a069f..e048f428f4 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/CarbonixF405/hwdef-bl.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/CarbonixF405/hwdef-bl.dat
@@ -15,8 +15,8 @@ APJ_BOARD_ID 1064
 # setup build for a peripheral firmware
 env AP_PERIPH 1
 
-# crystal frequency set to 0 to use internal clock
-OSCILLATOR_HZ 0
+# crystal frequency set to 0 to use internal clock; currently configured for external crystal 12MHZ
+OSCILLATOR_HZ 12000000
 
 # assume 1024K flash part
 FLASH_SIZE_KB 1024
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/CarbonixF405/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/CarbonixF405/hwdef.dat
index cd8ed70671..f75fcc4b95 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/CarbonixF405/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/CarbonixF405/hwdef.dat
@@ -16,8 +16,8 @@ APJ_BOARD_ID 1064
 # setup build for a peripheral firmware
 env AP_PERIPH 1
 
-# crystal frequency set to 0 to use internal clock
-OSCILLATOR_HZ 0
+# crystal frequency set to 12MHz to use internal clock
+OSCILLATOR_HZ 12000000
 
 #MCU F405 Flash 1024
 FLASH_SIZE_KB 1024
@@ -132,17 +132,26 @@ define HAL_PERIPH_GPS_PORT_DEFAULT 2
 #define HAL_PERIPH_ENABLE_NCP5623_LED_WITHOUT_NOTIFY
 
 # default ADSB off by setting 0 baudrate
-define HAL_PERIPH_ENABLE_ADSB
-define HAL_PERIPH_ADSB_PORT_DEFAULT 3
-define HAL_PERIPH_ADSB_BAUD_DEFAULT 57600
+# define HAL_PERIPH_ENABLE_ADSB
+# define HAL_PERIPH_ADSB_PORT_DEFAULT 3
+# define HAL_PERIPH_ADSB_BAUD_DEFAULT 57600
 
-BARO MS56XX I2C:0:0x76
-COMPASS MMC5XX3 I2C:0:0x30 false ROTATION_NONE
+define HAL_PERIPH_ARM_MONITORING_ENABLE 1
 
-define AP_COMPASS_QMC5883P_ENABLED 1
+BARO MS56XX I2C:0:0x76
 COMPASS QMC5883P I2C:0:0x2C false ROTATION_YAW_180
 
+#GPS Compass Enable
+define HAL_PROBE_EXTERNAL_I2C_COMPASSES
+COMPASS IST8310 I2C:ALL_EXTERNAL:0x0E true ROTATION_NONE
+
+# enable Rangefinder
+define HAL_PERIPH_ENABLE_RANGEFINDER 1
+
+define HAL_PERIPH_ENABLE_BATTERY 1
+
 define HAL_PERIPH_ENABLE_ESC_APD 1
 define APD_ESC_INSTANCES 4
 
+define AP_CUSTOM_FIRMWARE_STRING "CxPilot_V5.0.1"
 
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/CubeOrange/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/CubeOrange/hwdef.dat
index 3ae5a6ecb7..829204323d 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/CubeOrange/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/CubeOrange/hwdef.dat
@@ -4,3 +4,10 @@
 MCU STM32H7xx STM32H743xx
 
 include hwdef.inc
+
+define AP_CUSTOM_FIRMWARE_STRING "CxPilot_V5.0.1"
+
+define HAL_EFI_ENABLED 1
+define AP_EFI_SERIAL_HIRTH_ENABLED 1
+define AP_EFI_THROTTLE_LINEARISATION_ENABLED 1
+define AP_ICENGINE_TCA9554_STARTER_ENABLED 1