diff --git a/libraries/AP_HAL_ChibiOS/hwdef/MatekH7A3/hwdef-bl.dat b/libraries/AP_HAL_ChibiOS/hwdef/MatekH7A3/hwdef-bl.dat
index 5c8cb9539707f..5318c5d3eaebc 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/MatekH7A3/hwdef-bl.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/MatekH7A3/hwdef-bl.dat
@@ -21,29 +21,27 @@ FLASH_BOOTLOADER_LOAD_KB 32
 
 
 # order of UARTs (and USB). Allow bootloading on USB and telem1
-SERIAL_ORDER OTG1 UART7
+SERIAL_ORDER OTG1 USART1
 
-# UART7 (telem1)
-PE7 UART7_RX UART7 NODMA
-PE8 UART7_TX UART7 NODMA
+# USART1 (telem1)
+PB15 USART1_RX USART1 NODMA
+PB14 USART1_TX USART1 NODMA
 
 # PA10 IO-debug-console
 PA11 OTG_HS_DM OTG1
 PA12 OTG_HS_DP OTG1
 
-PA13 JTMS-SWDIO SWD
-PA14 JTCK-SWCLK SWD
+# PA13 JTMS-SWDIO SWD
+# PA14 JTCK-SWCLK SWD
 
 # make sure Vsw is on during bootloader
-PD10  PINIO1 OUTPUT LOW
+PC13  PINIO1 OUTPUT LOW
 
-PE3 LED_BOOTLOADER OUTPUT LOW
+PA14 LED_BOOTLOADER OUTPUT LOW
 define HAL_LED_ON 0
 
 # Add CS pins to ensure they are high in bootloader
-PC15 IMU1_CS CS
-PB12 MAX7456_CS CS
-PE11 IMU2_CS CS
-PD4 EXT_CS1 CS
-PE2 EXT_CS2 CS
-PC13 IMU3_CS CS
+PC4  IMU_CS CS
+PB2  MAX7456_CS CS
+PC15 FLASH_CS CS
+PC14 SD_CS CS
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/MatekH7A3/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/MatekH7A3/hwdef.dat
index 7892d58154471..392eba37e4a55 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/MatekH7A3/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/MatekH7A3/hwdef.dat
@@ -1,5 +1,5 @@
 # hw definition file for processing by chibios_pins.py
-# for Matek H7A3
+# for Matek H7A3-slim
 
 # MCU class and specific type
 MCU STM32H7xx STM32H7A3xx
@@ -17,185 +17,153 @@ env OPTIMIZE -Os
 FLASH_RESERVE_START_KB 32
 
 # ChibiOS system timer
-STM32_ST_USE_TIMER 12
-define CH_CFG_ST_RESOLUTION 16
+STM32_ST_USE_TIMER 5
+define CH_CFG_ST_RESOLUTION 32
 
-# USB
-PA11 OTG_HS_DM OTG1
-PA12 OTG_HS_DP OTG1
-
-PA13 JTMS-SWDIO SWD
-PA14 JTCK-SWCLK SWD
+define HAL_STORAGE_SIZE 15360
 
-# SPI1 for IMU1 (MPU6000)
-PA5 SPI1_SCK SPI1
-PA6 SPI1_MISO SPI1
-PD7 SPI1_MOSI SPI1
-PC15 IMU1_CS CS
+# use last 4 pages for flash storage
+# H7A3 has 256 pages of 8k each
+STORAGE_FLASH_PAGE 252
 
-# SPI2 for MAX7456 OSD
-PB12 MAX7456_CS CS
-PB13 SPI2_SCK SPI2
-PB14 SPI2_MISO SPI2
-PB15 SPI2_MOSI SPI2
+# use double page size for flash storage to effectively
+# give 16k pages
+define AP_FLASH_STORAGE_DOUBLE_PAGE 1
+# # # # # # # # # # # # # # # # # # # # # # 
 
-# SPI3 - external
-PB3 SPI3_SCK SPI3
-PB4 SPI3_MISO SPI3
-PB5 SPI3_MOSI SPI3
 
-# external CS pins
-PD4 EXT_CS1 CS
-PE2 EXT_CS2 CS
+# USB
+PA11 OTG_HS_DM OTG1
+PA12 OTG_HS_DP OTG1
 
-# SPI4 for IMU2 (ICM20602)
-PE11 IMU2_CS CS
-PE12 SPI4_SCK SPI4
-PE13 SPI4_MISO SPI4
-PE14 SPI4_MOSI SPI4
+# SPI1 for ICM42688P & MAX7456
+PA5 SPI1_SCK  SPI1
+PA6 SPI1_MISO SPI1
+PA7 SPI1_MOSI SPI1
 
-# add ICM42605 on SPI4 as a backup to replace ICM20602
-PC13 IMU3_CS CS
+# SPI2 for SD/NAND
+PB10 SPI2_SCK  SPI2
+PC2  SPI2_MISO SPI2
+PC3  SPI2_MOSI SPI2
 
-# two I2C bus
-I2C_ORDER I2C2 I2C1
+# CS pins
+PC4 IMU_CS CS
+PB2 MAX7456_CS CS
+PC15 FLASH_CS CS
+PC14 SD_CS CS
 
-# I2C1
-PB6 I2C1_SCL I2C1
-PB7 I2C1_SDA I2C1
+# ONE I2C bus
+I2C_ORDER I2C3
+PA8 I2C3_SCL I2C3
+PC9 I2C3_SDA I2C3
 
-# I2C2
-PB10 I2C2_SCL I2C2
-PB11 I2C2_SDA I2C2
 
 # ADC
 PC0 BATT_VOLTAGE_SENS ADC1 SCALE(1)
 PC1 BATT_CURRENT_SENS ADC1 SCALE(1)
 PA4 BATT2_VOLTAGE_SENS ADC1 SCALE(1)
-PA7 BATT2_CURRENT_SENS ADC1 SCALE(1)
+PC5 BATT2_CURRENT_SENS ADC1 SCALE(1)
 
 define HAL_BATT_MONITOR_DEFAULT 4
 define HAL_BATT_VOLT_PIN 10
 define HAL_BATT_CURR_PIN 11
 define HAL_BATT2_VOLT_PIN 18
-define HAL_BATT2_CURR_PIN 7
-define HAL_BATT_VOLT_SCALE 11.0
+define HAL_BATT2_CURR_PIN 8
+define HAL_BATT_VOLT_SCALE 21.0
 define HAL_BATT_CURR_SCALE 40.0
-define HAL_BATT2_VOLT_SCALE 11.0
-
-PC4 PRESSURE_SENS ADC1 SCALE(2)
-define HAL_DEFAULT_AIRSPEED_PIN 4
-
-PC5 RSSI_ADC ADC1
-#define BOARD_RSSI_ANA_PIN 8
+define HAL_BATT2_VOLT_SCALE 21.0
 
 # LED
 # green LED1 marked as B/E
 # blue LED0 marked as ACT
-PE3 LED0 OUTPUT LOW GPIO(90) # blue
-PE4 LED1 OUTPUT LOW GPIO(91) # green
+PA14 LED0 OUTPUT LOW GPIO(90) # blue
+PA13 LED1 OUTPUT LOW GPIO(91) # green
 define HAL_GPIO_A_LED_PIN 91
 define HAL_GPIO_B_LED_PIN 90
 define HAL_GPIO_LED_OFF 1
 
-# order of UARTs (and USB)
-SERIAL_ORDER OTG1 UART7 USART1 USART2 USART3 UART8 UART4 USART6
 
-# USART1 (telem2)
-PA10 USART1_RX USART1
-PA9  USART1_TX USART1
+# --------------------- UARTs ---------------------------
+SERIAL_ORDER OTG1  USART1 USART2 USART3 UART4 UART5 USART6
 
-# USART2 (GPS1)
-PD5 USART2_TX USART2
-PD6 USART2_RX USART2
+# USART1
+PB14  USART1_TX USART1
+PB15  USART1_RX USART1
 
-# USART3 (GPS2)
-PD9 USART3_RX USART3
-PD8 USART3_TX USART3
+# USART2 
+PA2 USART2_TX USART2
+PA3 USART2_RX USART2
 
-# UART4 (spare)
-PB9 UART4_TX UART4
-PB8 UART4_RX UART4
+# USART3
+PC10 USART3_TX USART3
+PC11 USART3_RX USART3
 
-# USART6 (RC input), SERIAL7
-PC7 TIM3_CH2 TIM3 RCININT PULLDOWN LOW
-PC6 USART6_TX USART6 NODMA
+# UART4
+PA0 UART4_TX UART4 NODMA
+PA1 UART4_RX UART4 NODMA
 
-# as an alternative config setup the RX6 pin as a uart. This allows
-# for bi-directional UART based receiver protocols such as FPort
-# without any extra hardware
-PC7 USART6_RX USART6 NODMA ALT(1)
+# UART5
+PC12 UART5_TX UART5 NODMA
+PD2  UART5_RX UART5 NODMA
 
-# UART7 (telem1)
-PE7 UART7_RX UART7
-PE8 UART7_TX UART7
-PE10 UART7_CTS UART7
-PE9  UART7_RTS UART7
+# USART6
+PC6  USART6_TX USART6 NODMA
+PC7  USART6_RX USART6 NODMA
 
-# UART8 (spare)
-PE0 UART8_RX UART8
-PE1 UART8_TX UART8
 
 # CAN bus
-PD0 CAN1_RX CAN1
-PD1 CAN1_TX CAN1
-PD3 GPIO_CAN1_SILENT OUTPUT PUSHPULL SPEED_LOW LOW GPIO(70)
-
-# Motors
-PB0  TIM8_CH2N TIM8  PWM(1)  GPIO(50)
-PB1  TIM8_CH3N TIM8  PWM(2)  GPIO(51)
-PA0  TIM5_CH1  TIM5  PWM(3)  GPIO(52)
-PA1  TIM5_CH2  TIM5  PWM(4)  GPIO(53)
-PA2  TIM5_CH3  TIM5  PWM(5)  GPIO(54)
-PA3  TIM5_CH4  TIM5  PWM(6)  GPIO(55)
-PD12 TIM4_CH1 TIM4 PWM(7) GPIO(56)
-PD13 TIM4_CH2 TIM4 PWM(8) GPIO(57)
-PD14 TIM4_CH3 TIM4 PWM(9) GPIO(58)
-PD15 TIM4_CH4 TIM4 PWM(10) GPIO(59)
-PE5  TIM15_CH1 TIM15 PWM(11) GPIO(60)
-PE6  TIM15_CH2 TIM15 PWM(12) GPIO(61)
-PA8 TIM1_CH1 TIM1 PWM(13) GPIO(62) # for WS2812 LED
+PB12 CAN2_RX CAN2
+PB13 CAN2_TX CAN2
+
+# PWM
+PA9  TIM1_CH2  TIM1  PWM(1)  GPIO(50)
+PA10 TIM1_CH3  TIM1  PWM(2)  GPIO(51)
+PA15 TIM2_CH1  TIM2  PWM(3)  GPIO(52)
+PB3  TIM2_CH2  TIM2  PWM(4)  GPIO(53)
+PB0  TIM3_CH3  TIM3  PWM(5)  GPIO(54)
+PB1  TIM3_CH4  TIM3  PWM(6)  GPIO(55)
+PB4  TIM3_CH1  TIM3  PWM(7)  GPIO(56)
+PB5  TIM3_CH2  TIM3  PWM(8)  GPIO(57)
+PB6  TIM4_CH1  TIM4  PWM(9)  GPIO(58)
+PB7  TIM4_CH2  TIM4  PWM(10) GPIO(59)
+PB8  TIM16_CH1 TIM16 PWM(11) GPIO(60)
 
 # Beeper
-PA15 TIM2_CH1 TIM2 GPIO(32) ALARM
-
-# microSD support
-PC8 SDMMC1_D0 SDMMC1
-PC9 SDMMC1_D1 SDMMC1
-PC10 SDMMC1_D2 SDMMC1
-PC11 SDMMC1_D3 SDMMC1
-PC12 SDMMC1_CK SDMMC1
-PD2 SDMMC1_CMD SDMMC1
+PB9  TIM17_CH1 TIM17 GPIO(32) ALARM
 
 # GPIOs
-PD10  PINIO1 OUTPUT GPIO(81) LOW
-PD11  PINIO2 OUTPUT GPIO(82) LOW
+PC13  PINIO1 OUTPUT GPIO(81) LOW
+define RELAY1_PIN_DEFAULT 81
 
 DMA_PRIORITY S*
+DMA_NOSHARE SPI1* SPI2*
 
-define HAL_STORAGE_SIZE 15360
 
-# use last 4 pages for flash storage
-# H7A3 has 256 pages of 8k each
-STORAGE_FLASH_PAGE 252
+# ------------------- IMU ICM42688p ------------------
+SPIDEV icm42688   SPI1 DEVID1 IMU_CS   MODE3  2*MHZ 16*MHZ
 
-# use double page size for flash storage to effectively
-# give 16k pages
-define AP_FLASH_STORAGE_DOUBLE_PAGE 1
+IMU Invensensev3  SPI:icm42688 ROTATION_NONE
+define HAL_DEFAULT_INS_FAST_SAMPLE 1
 
-# spi devices
-SPIDEV icm42688  SPI1 DEVID1 IMU1_CS      MODE3  2*MHZ 16*MHZ   # Clock is 100Mhz so highest clock <= 24Mhz is 100Mhz/8
-SPIDEV mpu6000   SPI1 DEVID1 IMU1_CS      MODE3  1*MHZ  4*MHZ
-SPIDEV icm20602  SPI4 DEVID1 IMU2_CS      MODE3  1*MHZ  4*MHZ
-SPIDEV icm42605  SPI4 DEVID1 IMU3_CS      MODE3  2*MHZ 16*MHZ
-SPIDEV osd       SPI2 DEVID4 MAX7456_CS   MODE0 10*MHZ 10*MHZ
 
+# ------------------ OSD AT7456E ----------------------
+SPIDEV osd       SPI1 DEVID4 MAX7456_CS   MODE0 10*MHZ 10*MHZ
 
-DMA_NOSHARE SPI1* SPI4*
+define OSD_ENABLED 1
+define HAL_OSD_TYPE_DEFAULT 1
+ROMFS_WILDCARD libraries/AP_OSD/fonts/font*.bin
 
-# SPI3 external connections
-SPIDEV pixartflow   SPI3 DEVID1  EXT_CS1  MODE3   2*MHZ  2*MHZ
 
+# --------------------- SD & FLASH ----------------------
+SPIDEV sdcard    SPI2 DEVID3 SD_CS      MODE0 400*KHZ 25*MHZ
+SPIDEV dataflash SPI2 DEVID1 FLASH_CS   MODE3 32*MHZ  32*MHZ
+
+define HAL_LOGGING_DATAFLASH_ENABLED 1
+define HAL_OS_FATFS_IO 1
+define HAL_LOGGING_DATAFLASH_DRIVER AP_Logger_W25N01GV
+
+
+# ----------------- I2C compass & Baro -----------------
 # no built-in compass, but probe the i2c bus for all possible
 # external compass types
 define ALLOW_ARM_NO_COMPASS
@@ -203,24 +171,7 @@ define HAL_PROBE_EXTERNAL_I2C_COMPASSES
 define HAL_I2C_INTERNAL_MASK 0
 define HAL_COMPASS_AUTO_ROT_DEFAULT 2
 
-# two IMUs
-# H743-V1,      ICM20602, MPU6000
-# H743-V1.5/V2, ICM42605, MPU6000
-# H743-V3,      ICM42688P, ICM42605
-IMU Invensensev3 SPI:icm42688 ROTATION_YAW_180
-IMU Invensensev3 SPI:icm42605 ROTATION_YAW_270
-IMU Invensense SPI:icm20602 ROTATION_ROLL_180_YAW_270
-IMU Invensense SPI:mpu6000 ROTATION_ROLL_180_YAW_270
-define HAL_DEFAULT_INS_FAST_SAMPLE 1
-
-# DPS310 integrated on I2C2 bus, multiple possible choices for external barometer
-BARO MS56XX I2C:0:0x77
-BARO DPS310 I2C:0:0x76
-BARO BMP280 I2C:0:0x76
-
-define HAL_OS_FATFS_IO 1
-
-# setup for OSD
-define OSD_ENABLED 1
-define HAL_OSD_TYPE_DEFAULT 1
-ROMFS_WILDCARD libraries/AP_OSD/fonts/font*.bin
+# built-in barometer
+BARO SPL06  I2C:0:0x76
+define AP_BARO_BACKEND_DEFAULT_ENABLED 0
+define AP_BARO_SPL06_ENABLED 1