Firmware Guide

Note

This guide describes how to flash the PX4 firmware to Betaflight on a MicoAir743v2 flight controller using DFU mode.

Caution

This guide applies only to the MicoAir743v2 flight controller. A full memory clearance will delete the installed PX4 firmware and its settings. Before you proceed, make sure you have selected the correct controller and firmware file.

MicoAir743v2 flight controller

Required Software and Files

Prepare the following before proceeding:

• Betaflight App — the app used to build firmware and configure your flight controller.

• STM32CubeProgrammer — utility required to clear the controller memory and flash new firmware.

• Betaflight firmware for MicoAir743v2 in .hex format — build and save it as described below.

Ensure STM32CubeProgrammer is fully installed before flashing the device.

How to Build and Save the HEX File

1. Open the Betaflight App and navigate to Firmware Flasher tab.

   

   Opening the Betaflight firmware flasher

   
   

2. In the Board & Build section, select the MICOAIR743V2 board and choose the required firmware release.

   

   Selecting the board and firmware release

   
   

3. Set OSD Protocol to Analog.

   

   Selecting the Analog OSD protocol

   
   

4. Click Load Firmware [Online] and wait for the build to complete.

   

   Starting the firmware build

   
   

5. Open the Flash tab. Once the build is successfully completed, click Save to download the HEX file to your computer. You will use this file in STM32CubeProgrammer.

   

   Saving the built HEX file

   
   

How to Enter DFU Mode

To flash the firmware, you must first put the flight controller into DFU (Device Firmware Upgrade) mode:

1. Disconnect the flight controller from your computer.

2. Press and hold the BOOT button on the controller.

3. While continuing to hold the BOOT button, connect the controller to your computer via USB.

4. Confirm that your computer recognizes the controller in DFU mode. In STM32CubeProgrammer, the device should appear as either a DFU device or STM32 Bootloader.

How to Install Betaflight Firmware

1. Open STM32CubeProgrammer and select the connection interface.

   

   Selecting connection interface

   
   

2. Select the USB interface.

   

   USB interface selected

   
   

3. Click the Refresh button located to the right of the Port list. STM32CubeProgrammer should detect the controller in DFU mode. If the device does not appear, revisit the How to Enter DFU Mode section.

   

   Refreshing DFU device

   
   

4. Click Connect to establish a link with the controller.

   

   Connecting DFU device

   
   

5. Perform a full memory erase: Click the Eraser icon in the lower-left corner of the window, confirm the action in the pop-up, and wait for the process to finish.

   

   Full erase

   
   

6. Click Open file and select the downloaded .hex firmware file for MicoAir743v2. The filename depends on the firmware version.

   

   Opening firmware file

   
   

7. Click Download and wait for the writing process to complete.

   

   Writing Betaflight

   
   

8. Once the writing is successful, click Disconnect.

   

   Controller disconnected

   
   

9. Disconnect the controller from the USB cable. Reconnect it without pressing the BOOT button. Open Betaflight App.

   

   Betaflight Configurator

   
   

Once the firmware installation is complete, proceed to the Betaflight Setup Guide.