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KiwiH743-Wing Flight Controller

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Overview

The KiwiH743-Wing is a Pixhawk-format flight controller system consisting of two boards: a Flight Controller and a Power Distribution Board (PDB). Designed for expendable quadcopters and long-range fixed-wing drones. Ready to use with Rover, Wing, Quadcopter, and Hexacopter configurations.

Premium features: GPS-less takeoff, IRC Tramp VTX control, VRX integration (TBS Fusion, Skyzone Steadyview).

Firmware

Features

  • STM32H743 MCU (480 MHz, 2 MB flash)
  • 12S power supply
  • 5V, 6/7V, 9/12V 5A BECs
  • ICM-42688P and ICM-45686 with power and hardware signal filtering
  • BMP388 barometer
  • Dual camera input, switchable
  • 8 motors + 7 servos (15 PWM outputs)
  • 5 UARTs, UART7 with flow control
  • 1 SPI, 1 I2C, FDCAN
  • 5 GPIOs, 2 relay outputs, 9/12V switch
  • Analog + digital VTX output
  • STM32G4 OSD
  • SD card via SDMMC
  • 40 x 42 mm board, 36 x 39 mm mounting holes

Technical Specifications

Processor

ParameterValue
MCUSTM32H743
ArchitectureARM Cortex-M7
Max Frequency480 MHz
Flash2048 KB (2 MB)
Crystal16 MHz external oscillator

Sensors

SensorPartNotes
IMU 1ICM-42688PExternal clock, hardware filtered
IMU 2ICM-45686Hardware filtered
BarometerBMP388
OSDSTM32G4Analog video overlay

Power

RailVoltageCurrent
Input12S (up to ~50V)
BEC 15V5A
BEC 26/7V5A
BEC 39/12V5A

Mechanical

ParameterValue
Board size39 x 39 mm
Mounting holes30.5 x 30.5 mm

Serial Ports

SerialUARTTX PinRX PinNotes
Serial 1UART1PB14PB15
Serial 2UART2PD5PD6
Serial 3UART3PD8PD9
Serial 4UART4PD1PD0
Serial 5UART5PB13PB12
Serial 6UART6PC6PC7
Serial 7UART7PE8PE7RTS: PE9, CTS: PE10
Serial 8UART8PE1PE0OSD UART

GPIOs, Relays, and AUX

Dedicated GPIO Pads

PadPinGPIODefaultArduPilot Relay Config
CAM SWPE2100RELAY1RELAY1_PIN=100 (hwdef default)
RELAY 1PD3101Output LOWRELAY2_PIN=101, RELAY2_FUNC=1
RELAY 2PD4102Output LOWRELAY3_PIN=102, RELAY3_FUNC=1
AUX 1PD7105Output LOWRELAY4_PIN=105, RELAY4_FUNC=1
AUX 2PB3106Output LOWRELAY5_PIN=106, RELAY5_FUNC=1
AUX 3PE5107Output LOW—
AUX 4PC13103Output LOWShared with VIDEO BOOT
VID NRSTPE3104Output LOWRELAY6_PIN=104 (hwdef default), inverted
CAN SILPE470Output LOWCAN silent mode
BUZZERPA1532Alarm—
LEDPD1190Status LED—

Note: RELAY1_PIN defaults to GPIO 100 (Camera Switch, PE2). RELAY6_PIN defaults to GPIO 104 (VIDEO_NRST, PE3 — STM32G4 OSD reset, active low). RELAY 1/2 pads are 9/12V switched outputs.

PWM Outputs

OutputPinGPIOTimerFunctionDShot Bidir
SERVO 1PA1050TIM1_CH3Motor 1No
SERVO 2PA951TIM1_CH2Motor 2No
SERVO 3PA852TIM1_CH1Motor 3No
SERVO 4PD1553TIM4_CH4Motor 4No
SERVO 5PD1454TIM4_CH3Motor 5No
SERVO 6PD1355TIM4_CH2Motor 6No
SERVO 7PD1256TIM4_CH1Motor 7No
SERVO 8PB157TIM3_CH4Motor 8No
SERVO 9PB058TIM3_CH3Servo 1No
SERVO 10PB459TIM3_CH1Servo 2No
SERVO 11PB560TIM3_CH2Servo 3No
SERVO 12PA361TIM5_CH4Servo 4No
SERVO 13PA262TIM5_CH3Servo 5No
SERVO 14PA163TIM5_CH2Servo 6No
SERVO 15PA064TIM5_CH1Servo 7No

PWM pins can be reassigned to GPIO via SERVOn_FUNCTION=0 + RELAYn_PIN=<gpio>.

Relay Usage

MAVProxy:

param set RELAY2_PIN 101
param set RELAY2_FUNC 1
relay set 0 1    # RELAY1 ON (CAM SW HIGH)
relay set 0 0    # RELAY1 OFF
relay set 1 1    # RELAY2 ON (RELAY1 pad HIGH)

Mission waypoint: DO_SET_RELAY — relay number 0-based (0=RELAY1), setting 1=ON / 0=OFF.

Lua:

relay:toggle(0)  -- toggle RELAY1 (CAM SW)
relay:on(1)      -- RELAY2 ON (RELAY1 pad)
relay:off(1)     -- RELAY2 OFF

All GPIO pads default LOW on boot. Use RELAY_DEFAULT params to set initial state.

OSD Reset (RELAY6):

RELAY6 controls the STM32G4 OSD reset line (VID NRST). Active low — set RELAY6_INVERTED=1 so that “relay on” pulls the line low (reset) and “relay off” releases it.

param set RELAY6_PIN 104
param set RELAY6_FUNCTION 1
param set RELAY6_INVERTED 1
relay set 5 1   # reset OSD
relay set 5 0   # release reset

Power Monitoring

FunctionPinADC
Battery voltagePC5ADC1 IN8, scale /21
Battery currentPC4ADC1 IN4
VBAT2PC3_CADC3 IN1, scale /21
ADC 1PC1ADC1 IN11
ADC 2PC0ADC1 IN10
ADC 3PC2_CADC3 IN0

Sensor Calibration

ParameterArduPilotBetaflight
Voltage scaleBATT_VOLT_MULT = 21.0voltage_meter_scale = 210
Current scaleBATT_AMP_PERVLT = 142.9current_meter_scale = 100

Battery Voltage Thresholds (ArduPilot)

Parameter6S8S12S
Full charge25.2 V33.6 V50.4 V
BATT_ARM_VOLT22.229.644.4
BATT_LOW_VOLT21.028.042.0
BATT_CRT_VOLT19.826.439.6

Buses

SPI

BusCLKMISOMOSIUsage
SPI 1PA5PA6PA7IMU 1 (CS: PB2)
SPI 4PE12PE13PE14IMU 2 (CS: PE15)

I2C

BusSCLSDA
I2C 1PB6PB7
I2C 2PB10PB11

FDCAN

FunctionPin
CAN RXPB8
CAN TXPB9
CAN SilentPE4

SDMMC (SD Card)

FunctionPin
D0PC8
D1PC9
D2PC10
D3PC11
CLKPC12
CMDPD2

Premium Features

GPS-less Takeoff (ArduPlane)

KIWI firmware supports autonomous takeoff without a GPS fix. Useful for hand launch or catapult deployment in GPS-denied environments.

Parameters:

ParameterValueDescription
FLIGHT_OPTIONS32768Enable GPS-less takeoff
ARMING_CHECK0Disable arming checks
TKOFF_ALT50Target takeoff altitude (meters)
TKOFF_THR_MINACC0No accelerometer trigger, timer only
TKOFF_THR_MINSPD0No minimum ground speed required
TKOFF_THR_MAX100Max throttle % during takeoff
TKOFF_THR_DELAY2Delay before launch (0.2s)

Procedure:

  1. Power on, wait for EKF convergence
  2. Set home (from GPS before loss, or manually via MAVLink)
  3. Arm in FBWA mode
  4. Switch to TAKEOFF mode

IRC Tramp VTX Control

Full IRC Tramp protocol support under ArduPilot. Change VTX power, band, channel, and pit mode directly from your GCS or OSD — no need for SmartAudio.

Works with TBS Unify, Rush Tank, and other Tramp-compatible VTXs.

VRX Integration (TBS Fusion / Skyzone)

Working video receiver control under ArduPilot. Supports:

  • TBS Fusion — band/channel tracking via CRSF
  • Skyzone Steadyview — auto channel sync

Camera Gimbal Support

KiwiH743-Wing supports camera gimbals out of the box — both servo-based and MAVLink protocol gimbals (CADDX GM3 V2 and compatible).

Wire gimbal UART to any free serial port (gimbal TX → FC RX, gimbal RX → FC TX, GND).

ParamValueNotes
SERIALx_PROTOCOL2MAVLink2
SERIALx_BAUD115115200 bps
MNT1_TYPE6Gremsy (reboot after setting)
MNT1_PITCH_MIN-120GM3 V2 spec: ±120°
MNT1_PITCH_MAX120
MNT1_YAW_MIN-160GM3 V2 spec: ±160°
MNT1_YAW_MAX160
MNT1_RC_RATE60deg/s for rate control, 0 for angle
RC Control

Assign RC channels to control gimbal axes:

ParamValueNotes
RC6_OPTION213Mount1 Pitch
RC7_OPTION214Mount1 Yaw
RC8_OPTION212Mount1 Roll (3-axis gimbals only)

Example: with MNT1_RC_RATE=60, moving the RC6 stick deflects pitch at 60°/s. Set MNT1_RC_RATE=0 for direct angle control (stick position = gimbal angle).

Gimbal firmware must be V2.0 or higher.

Servo Gimbal

Connect pitch/yaw servos to any Servo PWM outputs (SERVO 9–SERVO 15).

ParamValueNotes
MNT1_TYPE1Servo
SERVOx_FUNCTION6Mount1 Pitch (assign to desired output)
SERVOx_FUNCTION8Mount1 Yaw (assign to desired output)
MNT1_PITCH_MIN-90
MNT1_PITCH_MAX90
MNT1_YAW_MIN-170
MNT1_YAW_MAX170
MNT1_RC_RATE60deg/s for rate control, 0 for angle

Displayport OSD

HD OSD via MSP Displayport on SERIAL8 (OSD UART). Compatible with DJI O3, HDZero, Walksnail.

param set OSD_TYPE 5
param set OSD_UNITS 0
param set MSP_OPTIONS 4
param set MSP_OSD_NCELLS 0
param set SERIAL8_BAUD 115
param set SERIAL8_OPTIONS 0
param set SERIAL8_PROTOCOL 42

Flight Controller

Built around the STM32H743, the flight controller provides dual IMUs with hardware signal filtering, dual switchable camera inputs, and relay-controlled power outputs.

Power Distribution Board (PDB)

KiwiH743-Wing PDB

Features

  • 4S–12S power input
  • 5V 5A output
  • 5/6/7/9V 5A adjustable output
  • 12V 5A output
  • 3.3V 1A output
  • 0.1 mOhm current sensor
  • 36 x 39 mm mounting holes
  • 42 x 75 mm board dimensions

Other

FunctionPinNotes
USB D-PA11
USB D+PA12
SWDIOPA13Debug
SWDCLKPA14Debug
BuzzerPA15TIM2 CH1
LEDPD11Status
IMU clockPE6TIM15 CH2, external clock for IMUs
Video NRSTPE3OSD/VTX reset
Video BOOTPC13Shared with AUX 4

Full Pinout Reference

Port A (PA)

PinFunctionAlternate
PA0SERVO 15TIM5 CH1
PA1SERVO 14TIM5 CH2
PA2SERVO 13TIM5 CH3
PA3SERVO 12TIM5 CH4
PA4IMU 1 INT
PA5SPI 1 CLK
PA6SPI 1 MISO
PA7SPI 1 MOSI
PA8SERVO 3
PA9SERVO 2
PA10SERVO 1
PA11USB N
PA12USB P
PA13SWDIO
PA14SWDCLK
PA15BUZZERTIM2 CH1

Port B (PB)

PinFunctionAlternate
PB0SERVO 9
PB1SERVO 8ADC1 IN5
PB2IMU 1 CS
PB3AUX 2
PB4SERVO 10
PB5SERVO 11
PB6I2C 1 SCL
PB7I2C 1 SDA
PB8FDCAN RXTIM16 CH1
PB9FDCAN TXTIM17 CH1
PB10I2C 2 SCL
PB11I2C 2 SDA
PB12Serial 5 RX
PB13Serial 5 TX
PB14Serial 1 TX
PB15Serial 1 RX

Port C (PC)

PinFunctionAlternate
PC0ADC 2ADC1 IN10
PC1ADC 1ADC1 IN11
PC2_CADC 3ADC3 IN0
PC3_CVBAT2 / 21ADC3 IN1
PC4ESC CURRADC1 IN4
PC5VBAT / 21ADC1 IN8
PC6Serial 6 TXTIM3 CH1
PC7Serial 6 RXTIM3 CH2
PC8SDMMC D0TIM3 CH3
PC9SDMMC D1TIM3 CH4
PC10SDMMC D2
PC11SDMMC D3
PC12SDMMC CK
PC13VIDEO BOOT / AUX 4

Port D (PD)

PinFunctionAlternate
PD0Serial 4 RX
PD1Serial 4 TX
PD2SDMMC CMD
PD3RELAY 1
PD4RELAY 2
PD5Serial 2 TX
PD6Serial 2 RX
PD7AUX 1
PD8Serial 3 TX
PD9Serial 3 RX
PD11LED
PD12SERVO 7TIM4 CH1
PD13SERVO 6TIM4 CH2
PD14SERVO 5TIM4 CH3
PD15SERVO 4TIM4 CH4

Port E (PE)

PinFunctionAlternate
PE0Serial 8 RX
PE1Serial 8 TX
PE2CAMERA SWITCH
PE3VIDEO NRST
PE4FDCAN SILENT
PE5AUX 3TIM15 CH1
PE6IMU CLK INTIM15 CH2
PE7Serial 7 RX
PE8Serial 7 TX
PE9Serial 7 RTS
PE10Serial 7 CTS
PE11IMU 2 INTTIM1 CH2
PE12SPI 4 CLKTIM1 CH2
PE13SPI 4 MISOTIM1 CH3
PE14SPI 4 MOSITIM1 CH4
PE15IMU 2 CS