diff --git a/libraries/AP_HAL_ChibiOS/hwdef/KakuteF4/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/KakuteF4/hwdef.dat
index 646cce4656..9b8243326d 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/KakuteF4/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/KakuteF4/hwdef.dat
@@ -25,9 +25,6 @@ STM32_VDD 330U
 # only one I2C bus
 I2C_ORDER I2C1
 
-# order of UARTs (and USB)
-UART_ORDER OTG1 UART4 USART1 USART6 UART5
-
 # LEDs
 PB5 LED_BLUE OUTPUT LOW GPIO(0)
 
@@ -58,40 +55,49 @@ PC5 ICM20689_DRDY INPUT
 PB8 I2C1_SCL I2C1
 PB9 I2C1_SDA I2C1
 
-# rcinput is PB11
-PB11 TIM2_CH4 TIM2 RCININT FLOAT LOW
-
 # analog pins
 PC3 BATT_VOLTAGE_SENS ADC1 SCALE(1)
 PC2 BATT_CURRENT_SENS ADC1 SCALE(1)
 
+# RSSI analog input
+PC1 RSSI_ADC_PIN ADC1 SCALE(1)
+define BOARD_RSSI_ANA_PIN 11
+
 # define default battery setup
 define HAL_BATT_VOLT_PIN 13
 define HAL_BATT_CURR_PIN 12
 define HAL_BATT_VOLT_SCALE 10.1
 define HAL_BATT_CURR_SCALE 17.0
 
-# main port, for telem1
+# order of UARTs (and USB)
+UART_ORDER OTG1 UART4 USART6 USART1 UART5 USART3
+
+# rcinput is PB11
+PB11 TIM2_CH4 TIM2 RCININT FLOAT LOW
+PB10 USART3_TX USART3
+
+# SBUS inversion control pin, active low
+PB15 SBUS_INVERT OUTPUT LOW
+
+# for FrSky S.PORT. Has builtin inverters and diode to combine
+# RX and TX onto the one pin
 PA9 USART1_TX USART1
 PA10 USART1_RX USART1
 
-# USART3 for rcinput
-#PB10 USART3_TX USART3
-#PB11 USART3_RX USART3
-PB15 SBUS_INVERT OUTPUT LOW
+# default Serial2 to FrSky telemetry
+define HAL_SERIAL2_PROTOCOL_DEFAULT 10
 
-# USART6
+# USART6, telem1, SERIAL1
 PC6 USART6_TX USART6
 PC7 USART6_RX USART6
 
-# UART4 (GPS)
+# UART4 (GPS), SERIAL3
 PA1 UART4_RX UART4 NODMA
 PA0 UART4_TX UART4 NODMA
 
-# UART5 (ESC sensor)
+# UART5 (ESC telemetry sensor), SERIAL4
 PD2 UART5_RX UART5
 
-# PA10 IO-debug-console
 PA11 OTG_FS_DM OTG1
 PA12 OTG_FS_DP OTG1