Switching to PX4

This guide describes how to replace the Betaflight firmware by PX4 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 Betaflight 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:

• QGroundControl — app used to build PX4 firmware and configure your flight controller.

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

• PX4 firmware for MicoAir743v2 (.px4 format) — to be installed via QGroundControl.

• PX4 bootloader for MicoAir743v2 (.bin format) — to be written via STM32CubeProgrammer prior to firmware installation.

Ensure STM32CubeProgrammer and QGroundControl are fully installed before flashing the device.

How to Write the PX4 Bootloader

1. Press and hold the BOOT button on the controller. While continuing to hold the BOOT button, connect the controller to your computer via USB.

2. Open STM32CubeProgrammer and select the connection interface.

   

   Selecting connection interface

   
   

3. Select the USB interface.

   

   USB interface selected

   
   

4. Click the Refresh button located to the right of the Port list. STM32CubeProgrammer should detect the controller in DFU mode. If the port is not detected, reconnect the controller while continuing to hold the BOOT button.

   

   Refreshing DFU device

   
   

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

   

   Connecting DFU device

   
   

6. 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

   
   

7. Click Open file and select the downloaded micoair_h743-v2_bootloader.bin file.

   

   Opening bootloader file

   
   

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

   

   Writing PX4 bootloader

   
   

9. Once the writing is successful, click Disconnect.

   

   Controller disconnected

   
   

10. Close STM32CubeProgrammer and disconnect the controller from your computer.

How to Install the PX4 Firmware

1. Open QGroundControl.

2. Connect the flight controller to your computer via USB (do not press the BOOT button this time).

3. Click the QGroundControl logo located in the upper-left corner.

   

   QGroundControl main menu

   
   

4. Select Configure from the drop-down menu to open the Vehicle Configuration panel.

   

   Configure in QGroundControl

   
   

5. Select the Firmware section.

   

   Opening Firmware menu

   
   

6. Select your controller from the port list and click Flash.

   

   Selecting controller

   
   

7. If QGroundControl prompts you to reconnect the controller, follow the on-screen instructions (remember: do not press the BOOT button).

   

   Reconnecting controller

   
   

8. In the Firmware Setup window, enable Advanced settings, select Custom firmware file... and click OK. Locate and select the micoair_h743-v2_default.px4 file.

   

   Selecting firmware from file

   
   

9. Wait for the firmware writing process to complete.

   

   Uploading PX4

   
   

10. Next Steps: proceed to configuring the flight controller.

    

    Flight controller with PX4 installed