MicoAir743v3 Flight Controller User Manual

Product Overview

MicoAir743v3 is MicoAir Tech's next-generation flagship H7 flight controller for multirotors and autonomous flight platforms, building on the MicoAir743v2. It features a 480 MHz STM32H743VIT6 MCU, dual high-performance IMUs (BMI088 + ICM45686), a SPA06 barometer, an onboard IST8310 magnetometer, an AT7456E analog OSD chip, and a microSD card slot for flight logs.

The controller provides 7 UARTs, 11 PWM outputs, 1 CAN interface, 1 I²C interface, two BEC outputs, a digital video transmitter (VTX) interface, and onboard dual-mode Bluetooth telemetry. It supports open-source firmware including ArduPilot, PX4, INAV, and Betaflight.

Compared with v2, MicoAir743v3 features upgraded sensors for improved performance and adds a CAN interface for the growing range of CAN peripherals. The SD card interface has been optimized to meet the high-speed storage requirements of certain firmware platforms. The onboard Bluetooth module now supports both SPP and BLE for more convenient connectivity. The power circuitry has also been refined, with switchable 9 V power for the VTX.

Key Features

• STM32H743VIT6, 480 MHz, 2 MB Flash
• Dual IMUs: BMI088 + ICM45686
• SPA06 barometer and onboard IST8310 magnetometer
• AT7456E analog OSD and MSP DisplayPort support for digital FPV systems
• 7 UARTs, 11 PWM outputs, 1 CAN interface, 1 I²C interface, and 1 SWD interface
• microSD card slot for flight log storage
• Onboard SPP/BLE dual-mode Bluetooth telemetry, internally connected to UART8 at a default baud rate of 115200
• Two BEC outputs: 4.6 V / 2 A and 9 V / 2 A; the 9 V output supports GPIO-controlled switching
• 2–6S battery input, 6–27 V
• Support for ArduPilot, PX4, INAV, and Betaflight firmware

Purchase

MicoAir Tech Store

Hardware Specifications

Processor and Sensors

Interfaces and Outputs

Power and Dimensions

Dimensions and Installation

Follow these guidelines when installing the flight controller:

1. Use the 30.5 × 30.5 mm mounting pattern. Ensure that screws and washers do not contact components on the board.
2. Use vibration-damping mounts where possible. Tighten them evenly without bending the board.
3. Point the arrow on the flight controller toward the front of the aircraft. If the installation requires a different orientation, set the corresponding board orientation parameters in the firmware.

Interfaces and Power Supply

Connector Pinouts

Typical Wiring

Power Connections

Pin 1 of the digital video connector supplies 9 V. Before connecting a DJI O3/O4 air unit or another VTX, verify the pin order and the device's input voltage requirements. Do not connect 9 V to a receiver, GPS module, or camera rated for 5 V only.

Serial communication usually requires TX, RX, and GND. Connect the flight controller's TX to the peripheral's RX, and its RX to the peripheral's TX. For a unidirectional protocol, connect only the signal line required by that protocol, along with the appropriate ground connection.

Serial Port Mapping

UART8 is used by the onboard Bluetooth module. Its default baud rate is 115200.

PWM Outputs

MicoAir743v3 provides up to 11 PWM outputs: 10 motor outputs and one output shared with the LED function. PWM1–PWM8 have hardware support for DShot and bidirectional DShot; availability depends on the installed firmware and its version.

PWM Timer Groups

Different output protocols generally cannot be mixed arbitrarily within the same timer group. When changing the PWM protocol, output rate, or addressable LED configuration, check all channels in that group together.

When PWM11 is configured for addressable LEDs, PWM7 and PWM8 are subject to the same timer-group restrictions and may also be limited to LED-compatible configurations. Follow the output grouping rules for your installed firmware.

ESC Protocol Recommendations

• Standard PWM ESCs: select a standard PWM protocol supported by the firmware.
• DShot ESCs: DShot300 is generally a good starting point, balancing reliability and bandwidth.
• Bidirectional DShot: both the flight controller firmware and ESC firmware must support it.

Remove all propellers before testing motors. Verify motor numbering, rotation direction, and failsafe behavior before reinstalling the propellers and proceeding with controlled ground tests.

Receivers

UART6 is the default RC input. With ArduPilot, other available UARTs can also be configured according to the receiver protocol's requirements.

If a CRSF/ELRS receiver is not detected, first check that TX and RX are crossed correctly, the supply voltage is correct, and UART6 is not assigned to another function. Do not identify pins by wire color alone.

OSD and Video Interfaces

MicoAir743v3 provides both AT7456E analog OSD and MSP DisplayPort support for digital FPV systems such as DJI O3/O4.

Analog OSD

• Onboard chip: AT7456E
• In ArduPilot, set OSD_TYPE = 1 to enable the MAX7456-compatible driver.
• Before use, check the camera's video standard, video input/output wiring, and firmware support.

MSP DisplayPort / DJI O3/O4

• Connect the digital VTX using the SH1.0-6P connector.
• UART2 is used for MSP DisplayPort by default.
• The video connector supplies 9 V.
• OSD features and configuration procedures vary by firmware version. Refer to the documentation for your installed firmware.

Before connecting the VTX, confirm again that pin 1 supplies 9 V. Incorrect wiring can damage both the VTX and the flight controller.

Battery Monitoring, Magnetometer, and I²C

Battery Voltage and Current Monitoring

The flight controller has onboard voltage sensing and receives the current sensor signal through the ESC connector. It supports batteries up to 6S.

The default parameters in the official ArduPilot hardware definition are listed below:

The current sensor scaling factor depends on the sensor circuitry in the ESC. The values above are MicoAir743v3 defaults and are not suitable for every ESC. Adjust them for the hardware you are using.

Magnetometer

• Onboard magnetometer: IST8310
• An external magnetometer can be connected to the I²C SDA / SCL pins.
• High-current wiring, buzzers, magnets, and motors can cause magnetic interference.

For applications requiring greater heading accuracy, use an external GPS/compass module mounted away from the power system, and recalibrate the compass after completing the aircraft assembly.

Connecting via Bluetooth

The onboard Bluetooth telemetry module is internally connected to UART8 at a default baud rate of 115200. It supports both SPP and BLE. SPP offers broad compatibility and can be used with apps such as QGroundControl on Android. BLE provides a quick, convenient connection but requires compatible software. Both MicoConfigurator and MicoPilot support BLE connections to MicoAir743v3, making BLE the generally recommended option.

Bluetooth can be used for ground-based parameter configuration and flight controller status monitoring.

Enabling Bluetooth Power (Enabled by Default)

1. Power on the flight controller normally and wait at least 3 seconds.
2. Check the blue Bluetooth power LED.
3. If the LED is off, press and hold the BOOT button for approximately 2 seconds to turn Bluetooth on.
4. Press and hold the button again to turn Bluetooth off. The on/off state is retained after power is removed.

Connecting via BLE in MicoConfigurator

In the connection dialog, select Bluetooth BLE, then click Select Device. In the Bluetooth device picker, select the device named MicoAir743v3-xxxxx and click Pair.

Once paired, the device name appears in the connection dialog. Click Connect. MicoConfigurator will establish the Bluetooth connection and begin loading the flight controller parameters.

The green Bluetooth status LED on the flight controller stays on once the Bluetooth connection is established.

Connecting via BLE in MicoPilot

Open MicoPilot, tap Connect in the upper-right corner, and select Bluetooth as the connection method.

The Bluetooth connection dialog automatically scans for nearby devices. Wait a few seconds, then select MicoAir743v3-xxxxx from the list to pair with it. MicoPilot will automatically connect to the flight controller and begin loading its parameters. This typically takes 4–5 seconds with ArduPilot firmware. Actual connection time may vary.

Flight Controller Firmware

MicoAir743v3 supports ArduPilot, PX4, INAV, and Betaflight.

MicoConfigurator is a browser-based flight controller configuration tool for Windows, macOS, and Linux. It can be used to configure and troubleshoot the flight controller, and to update firmware using online downloads, local files, or DFU mode.

Open MicoConfigurator in Chrome or Edge. After entering DFU mode, select the board and firmware in the browser to flash the flight controller. Windows requires a DFU driver.

ArduPilot

• MicoAir743v3 ArduPilot 4.6.3 & 4.7.2 firmware

PX4

• MicoAir743v3 PX4 1.17.0 firmware

INAV

• MicoAir743v3 INAV 9.1.0 firmware

Betaflight

• MicoAir743v3 Betaflight 2026.6.2 firmware

Firmware Flashing and Recovery

Updating Firmware

1. Back up the current parameters.
2. Use MicoConfigurator or Mission Planner to update to stable firmware online.
3. After flashing is complete, power-cycle the flight controller.

Entering DFU Mode

1. Disconnect the flight controller from its power supply and USB.
2. Press and hold the BOOT button.
3. While holding the button, connect the USB Type-C cable.
4. Release the button once the computer detects the DFU device.
5. Select the correct firmware target on the firmware/DFU page in MicoConfigurator and flash the firmware.

In DFU mode, the flight controller does not appear as a serial port in Device Manager as it does when normal firmware is running, and the LED indicators do not operate. This is normal.

Appendix A: MCU Pin Assignments

This table is primarily intended for low-level driver development and hardware debugging. It is generally not needed for routine assembly or parameter configuration.