AirBrainH743

GearUp AirBrain H743 flight controller. STM32H743VIH6 (480 MHz Cortex-M7), 36 × 31 × 10 mm, 8 g. Designed and made in Belgium.

This repository hosts the datasheet, pinouts, mechanical resources, and integration guides for the board. Source-of-truth for the product is the Airbrain product page.

Firmware support

The AirBrain H743 is officially supported upstream by Betaflight, ArduPilot, and PX4. Targets live in each project's main branch.

Stack	Target	Canonical source
Betaflight	AIRBRAINH743	Betaflight Configurator, Firmware Flasher, board dropdown
ArduPilot	AIRBRAINH743	Latest builds for Copter, Plane, Rover, Sub
PX4	gearup_airbrainh743_default	Latest CI build (.px4)

Boards ship pre-flashed with Betaflight.

INAV is in beta. Targets are present in this repo's firmware/INAV/ folder for testing.

Pinout & Datasheet

Latest datasheet and pinouts: /datasheet.

Switching firmware stacks

Boards ship with Betaflight. Switching to ArduPilot or PX4 is a one-time operation on a desktop computer. After switching, you can switch back with the same procedure.

Entering DFU mode

DFU (Device Firmware Update) is the STM32's built-in ROM bootloader. It's required for the first install of any firmware family, for switching bootloaders (PX4, ArduPilot), and for recovery. Two routes into DFU:

• Hardware (BOOT button): hold the on-board BOOT button while plugging in the USB cable. Release after the board enumerates. This route works regardless of which firmware is currently on the board, including a bricked board.
• From Betaflight Configurator: with Betaflight running, click Activate Boot Loader in the top right. The board reboots into DFU. Only works while Betaflight is running. If the board has ArduPilot or PX4 on it, use the BOOT button.

In DFU mode the board enumerates as a USB DFU device ("STM32 BOOTLOADER" or "DFU in FS Mode") and no longer responds as a serial device until you flash and exit.

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Betaflight, to ArduPilot

ArduPilot uses its own bootloader (different from Betaflight's monolithic flash layout). For a clean first install on an AirBrain that's running Betaflight, we recommend flashing the with-bootloader ArduPilot variant first; subsequent updates can use the no-bootloader .apj via Mission Planner over USB-MAVLink.

1. Go to firmware.ardupilot.org/Copter/latest/AIRBRAINH743/ (replace Copter with Plane, Rover, Sub, etc. for your vehicle type).
2. Two files are published per release (vehicle-prefixed, e.g. arducopter, arduplane):
   • <vehicle>_with_bl.hex: contains the ArduPilot bootloader and firmware as a multi-region Intel HEX file. Use this for the first flash from a Betaflight board.
   • <vehicle>.apj: firmware only. Use this for over-MAVLink updates once the ArduPilot bootloader is on the board.
3. Put the AirBrain in DFU mode (BOOT button + USB).
4. Open Mission Planner (or QGroundControl).
5. Use the GCS's custom-firmware install option and select the _with_bl.hex file. Follow the on-screen prompts.
6. Wait for the flash to complete. The board reboots into ArduPilot.

For subsequent ArduPilot version bumps, you can connect the GCS to the running ArduPilot board over USB and flash the no-bootloader .apj directly.

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Betaflight, to PX4

PX4 uses its own bootloader, distinct from the Betaflight/ArduPilot bootloader. So switching to PX4 is a two-step flash: bootloader, then firmware.

Step 1: Flash the PX4 bootloader

Get the PX4 bootloader binary from this repo: firmware/PX4/bin/bootloader/gearup_airbrainh743_bootloader.bin.

Pick whichever flashing tool you're most comfortable with. The board needs to be in DFU mode for all three.

Option A: Betaflight Configurator (cross-platform, GUI)

Betaflight Configurator's Firmware Flasher can load any local .bin and write it via the STM32 ROM DFU. Works in both the desktop app and the web Configurator at app.betaflight.com.

1. Open Betaflight Configurator.
2. Put the AirBrain in DFU mode (see "Entering DFU mode" above).
3. Go to the Firmware Flasher tab.
4. Click Load Firmware [Local] and select gearup_airbrainh743_bootloader.bin.
5. Click Flash Firmware.

Reported to work by upstream maintainers; not yet self-verified by GearUp end-to-end. If it fails, fall back to Option B (STM32CubeProgrammer) or Option C (dfu-util).

Option B: STM32CubeProgrammer (official ST tool, GUI, cross-platform)

Download STM32CubeProgrammer from ST.

1. Put the AirBrain in DFU mode.
2. Open STM32CubeProgrammer.
3. Connection dropdown (top right): select USB, then your DFU device, click Connect.
4. Click the Erasing & Programming tab on the left.
5. Browse to gearup_airbrainh743_bootloader.bin.
6. Set start address to 0x08000000.
7. Click Start Programming.

Option C: dfu-util (CLI, Linux/macOS)

dfu-util -a 0 -s 0x08000000:leave \
  -D gearup_airbrainh743_bootloader.bin

Step 2: Flash the PX4 firmware

After flashing the bootloader, the board reboots and enumerates as a PX4 device. Two routes work, pick whichever fits your setup.

Option A: QGC Daily, Developer Build (recommended until PX4 v1.18 stable)

The AirBrain H743 target is on PX4 main branch but not yet in PX4 stable (v1.17). Until v1.18 lands, the cleanest route is QGC Daily, which auto-downloads the latest build from main.

1. Download QGC Daily from docs.qgroundcontrol.com/Stable_V5.0/en/qgc-user-guide/releases/daily_builds.html.
2. Open QGC Daily, go to Vehicle Configuration, Firmware, pick the USB port, click Flash.
3. Unplug and replug the USB cable when prompted.
4. Select Advanced Settings, choose Developer Build (master).
5. QGC pulls the latest .px4 from PX4 main and flashes it.

After PX4 v1.18 stable releases (expected later in 2026), QGC Stable will pick the AirBrain target automatically. We will update this section then.

Option B: Manual download

For air-gapped systems or when you want a specific build pinned.

1. Download the latest PX4 firmware: gearup_airbrainh743_default.px4. This is the official PX4 CI build, automatically rebuilt from PX4 main branch.
2. Open QGroundControl.
3. Connect the AirBrain via USB.
4. Use Vehicle Setup, Firmware, click Advanced Settings, choose Custom firmware file.
5. Select the .px4 file you downloaded.
6. Wait for the flash to complete.

Internal magnetometer note. The LIS2MDL chip is detected by PX4 iis2mdc driver out of the box. PX4 dmesg should show iis2mdc #0 on I2C bus 1 address 0x1E rotation 2. No board-config change required. Verified 2026-06-16 with PX4 contributor Julian Oes.

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ArduPilot or PX4, back to Betaflight

Betaflight is a monolithic image flashed directly at 0x08000000 via STM32 ROM DFU. Going back from ArduPilot or PX4 wipes the previous bootloader and replaces it with Betaflight in one operation.

The "Activate Boot Loader" button in Betaflight Configurator only exists when Betaflight is already running. From ArduPilot or PX4 you must use the hardware BOOT button to enter DFU.

1. Put the AirBrain in DFU mode (hold BOOT button + plug in USB).
2. Open Betaflight Configurator (desktop app or web Configurator at app.betaflight.com).
3. Go to the Firmware Flasher tab.
4. Select target AIRBRAINH743 from the dropdown.
5. Pick the latest stable Betaflight release.
6. Check Full chip erase (recommended; clears any leftover ArduPilot bootloader area or PX4 NAND filesystem state).
7. Click Load Firmware [Online], then Flash Firmware.

GearUp has a cloud-build partnership integration in Betaflight Configurator, so AirBrain targets are available in the official Configurator dropdown without any extra setup.

Offline recovery: if Betaflight Configurator's online flasher is unavailable, the factory-default Betaflight binary is at firmware/Betaflight/bin/airbrain_h743_factory_recovery.bin. Recovery only, see that folder's README for flashing instructions.

ArduPilot integration notes

Common gotchas when running ArduPilot on the AirBrain H743, based on upstream maintainer feedback.

ArduPilot 4.7 parameter rename, QGroundControl error

ArduPilot 4.7 renamed a large number of parameters. Notably, ARMING_CHECK was removed and replaced with ARMING_SKIPCHK (the meaning is inverted). QGroundControl has not yet been updated to recognise the new 4.7 parameter set, which surfaces as "missing parameter" errors after a fresh flash from the latest ArduPilot build.

Workaround: use the beta version of Mission Planner, which tracks the latest ArduPilot parameter set.

The AIRBRAINH743 target was added to ArduPilot after the stable-4.6 branch was cut, so the standard 4.6 stable downloads do not include AirBrain. The latest CI build is the canonical source.

SBUS receiver on RX5 (UART5)

To run an SBUS receiver on the AirBrain's RX5 pin (UART5 in ArduPilot), disable RCIN on the default UART (UART2) and enable it on UART5:

SERIAL2_PROTOCOL = -1
SERIAL5_PROTOCOL = 23

After setting these and rebooting, the RX5 pin will accept SBUS input.

Building from source

If you want to build PX4, ArduPilot, or Betaflight firmware yourself, see BUILD.md. The repo's firmware/<stack>/ folders contain target definitions and source where applicable, but upstream is canonical: please contribute target changes upstream.

3D files

The /3D folder contains a STEP file for the 30 × 30 to 20 × 20 mm mounting adapter.

Additional printable mounts, brackets, and housings are published on our MakerWorld page.

Repo layout

Path	Contents
/datasheet	Latest datasheet PDF + pinout images
/firmware/PX4/bin/bootloader/	PX4 bootloader binary
/firmware/PX4/sourcecode/	PX4 target source (mirror of upstream)
/firmware/Ardupilot/	ArduPilot target source (mirror of upstream)
/firmware/Betaflight/	Betaflight target source (mirror of upstream) + factory-default .bin for offline recovery
/3D	STEP file for 30 × 30 to 20 × 20 mounting adapter
BUILD.md	Build-from-source guide for all three firmware families
LICENSE.md	License terms

License

See LICENSE.md.

Contact

• Website: takeyourgear.com
• Email: info@takeyourgear.com
• Issues: please use this repo's Issues for documentation and integration questions