diff --git a/libraries/AP_HAL_ChibiOS/hwdef/PH4-mini/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/PH4-mini/hwdef.dat
index ea0a56d7a8..b292ace9c5 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/PH4-mini/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/PH4-mini/hwdef.dat
@@ -4,12 +4,35 @@
 
 include ../fmuv5/hwdef.dat
 
+# we shift the system timer to TIM5 to allow
+# us to use TIM2 for extra PWM outputs
+STM32_ST_USE_TIMER 5
+
+# order of UARTs (and USB). Telem2 is UART4 on the mini, USART3 is not available
+UART_ORDER OTG1 USART1 USART2 UART4 USART6 UART7
+
+# enable TX on USART6 (disabled for fmuv5 with iomcu)
+PG14 USART6_TX USART6 NODMA
+
+# disable the IOMCU UART
 undef IOMCU_UART
 undef UART8_TX
 undef UART8_RX
 undef AP_FEATURE_SBUS_OUT
 
-# RCInput
+# allow the first 3 capture ports to be used as PWM outputs or GPIOs
+undef PA5
+undef PB3
+undef PB11
+undef FMU_CAP1
+undef FMU_CAP2
+undef FMU_CAP3
+
+PA5  TIM2_CH1 TIM2 PWM(9)  GPIO(58)
+PB3  TIM2_CH2 TIM2 PWM(10) GPIO(59)
+PB11 TIM2_CH4 TIM2 PWM(11) GPIO(60)
+
+# RCInput on the PPM pin, for all protocols
 PI5 TIM8_CH1 TIM8 RCININT PULLUP LOW
 
 # setup for supplied power brick
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/fmuv5/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/fmuv5/hwdef.dat
index 3b04d714fe..63d895bbe7 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/fmuv5/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/fmuv5/hwdef.dat
@@ -139,7 +139,9 @@ PD1 UART4_TX UART4 NODMA
 
 # USART6 is telem3
 PG9 USART6_RX USART6 NODMA
-PG14 USART6_TX USART6 NODMA
+# we leave PG14 as an input to prevent it acting as a pullup
+# on the IOMCU SBUS input
+# PG14 USART6_TX USART6 NODMA
 PG15 USART6_CTS USART6
 PG8 USART6_RTS USART6