diff --git a/libraries/AP_HAL_ChibiOS/hwdef/ARK_FPV/hwdef-bl.dat b/libraries/AP_HAL_ChibiOS/hwdef/ARK_FPV/hwdef-bl.dat
index 5e96b7c25a9ee..0c115c02c0aae 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/ARK_FPV/hwdef-bl.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/ARK_FPV/hwdef-bl.dat
@@ -10,13 +10,10 @@ FLASH_BOOTLOADER_LOAD_KB 128
 
 env OPTIMIZE -Os
 
-SERIAL_ORDER OTG1 UART7 UART5 USART3
+SERIAL_ORDER OTG1 UART7 USART1 USART3
 
-# CS pins
-# SPI1 - IIM42653
-PI9 IMU1_CS CS
-# SPI6 - external
-PI10 EXT1_CS CS
+PI9  IMU1_CS CS # SPI1 CS - IIM42653
+PI10 EXT1_CS CS # SPI6 CS - external
 
 # Telem1 - Telem
 PE8  UART7_TX  UART7
@@ -24,6 +21,10 @@ PF6  UART7_RX  UART7
 PF8  UART7_RTS UART7
 PE10 UART7_CTS UART7
 
+# GPS
+PB6 USART1_TX USART1
+PB7 USART1_RX USART1
+
 # Armed indication
 PE6 nARMED OUTPUT HIGH
 
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/ARK_FPV/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/ARK_FPV/hwdef.dat
index 17eadb388d260..77b1e0f528fa0 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/ARK_FPV/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/ARK_FPV/hwdef.dat
@@ -58,7 +58,7 @@ PC7 USART6_RX USART6
 PA0 SCALED1_V3V3 ADC1 SCALE(2)
 PB1 VDD_5V_SENS ADC1 SCALE(2)
 # TODO: 12V monitor
-# PA4 SCALED2_V3V3 ADC1 SCALE(2)
+# PA4 SCALED2_V3V3 ADC1 SCALE(7.66)
 
 PB0 BATT_VOLTAGE_SENS ADC1 SCALE(1)
 PC2 BATT_CURRENT_SENS ADC1 SCALE(1)
@@ -93,7 +93,7 @@ PD11 DRDY_ADIS16507 INPUT GPIO(93)
 # GPIO(93) for data ready on ADIS16507
 # define ADIS_DRDY_PIN 93
 
-# Motors
+# Motors, see STM32H743xx.py
 PI0  TIM5_CH4 TIM5 PWM(1) GPIO(50) BIDIR
 PH12 TIM5_CH3 TIM5 PWM(2) GPIO(51) BIDIR
 PH11 TIM5_CH2 TIM5 PWM(3) GPIO(52) BIDIR
@@ -144,9 +144,7 @@ PE6 nARMED OUTPUT HIGH
 PC13 VDD_3V3_SD_CARD_EN OUTPUT HIGH
 PI11 VDD_3V3_SENSORS1_EN OUTPUT HIGH
 
-# (12V EN) start peripheral power off, then enable after init
-# this prevents a problem with radios that use RTS for
-# bootloader hold
+# 12V enable, start with it off
 PG4 nVDD_5V_PERIPH_EN OUTPUT HIGH
 
 # Power sensing
@@ -174,8 +172,7 @@ define AP_NOTIFY_GPIO_LED_RGB_ENABLED 1
 
 # ID pins
 PG0 HW_VER_REV_DRIVE OUTPUT LOW
-# PH3 HW_VER_SENS ADC3 SCALE(1)
-# PH4 HW_REV_SENS ADC3 SCALE(1)
+PH4 HW_REV_SENS ADC3 SCALE(1)
 
 # Barometer on i2c_2
 BARO BMP388 I2C:1:0x76