Standard Bootloader Upload Instructions

The Standard Bootloader

The standard bootloader can be used to upload new firmware versions on to the Falcon 1 and 2 flight controllers. The standard bootloader was shipped with earlier Falcon 1 and 2 boards and requires the use of an application called Bossa to upload new code.

Current boards are now shipped with the UF2 bootloader.


Uploading the latest firmware to the Falcon boards requires only an A to micro B USB cable, to connect it to a laptop or PC.

Upgrading Falcon 1 and 2 Firmware

To upload the latest firmware to your Falcon board, please follow these upload instructions:

  1. Warning: Please first remove the aircraft’s propellers.
  2. Download the appropriate Falcon .bin file that contains the new firmware, from either the Falcon 1 Updates or the Falcon 2 Updates webpage and copy it to your desired directory/folder location.
  3. Go to the following webpage:
  4. Download the appropriate Bossa 1.8 application for your platform:
  5. Windows x86 (32-bit) installer:
    Window x64 (64-bit) installer:
    Apple Mac OS X installer:

  6. Unzip/extract the file and install the Bossa application.
  7. Launch the Bossa application (double click on “Bossa.exe”), as shown in the image below:
  8. Bossa

  9. Unplug your multi-rotor battery (if connected), then connect the micro USB cable to the Falcon’s micro USB port.
  10. Falcon USB

  11. Connect the other end to the PC, this will power up the board. This is OK, even with the ESCs attached, although if you’re using the low voltage battery alarm, you may have to set the alarm voltage and trim (in the Miscellaneous Settings menu) to zero to silence it). You should hear a device connection tone on the PC. If the flight controller hasn’t been connected before, it may need some time to search for the required drivers.
  12. Double tap the Falcon’s reset button, (two presses in quick succession), this puts the Falcon into bootloader mode. The board will reboot, the OLED display however should remain blank. You may hear the PC device disconnection and connection tones, as the flight controller switches COM port to transfer control to its bootloader.
  13. In the Bossa application press the “Refresh” button and select the COM port from the drop down list.
  14. Use the “Browse” button and select the Falcon’s binary (.bin) file, downloaded from the Flitetronix website (in step 2 above).
  15. In the Bossa application check the boxes “Erase All” and “Boot to flash”, as shown in the image above.
  16. Select the “Info” button to ensure that Falcon’s processor is responding, as shown in the image below. Click on OK to close this pop-up dialog box.
  17. BossaInfo

  18. In the Bossa application, click on the “Write” button.
  19. If the write has been successful then click on the “Verify” button.
  20. If the verify process has been successful then press the Falcon’s reset button to re-start the flight control program oncemore. The OLED display will remain blank for a few seconds longer than usual as the new settings are initialised. The Falcon splash screen should be displayed before entering SAFE mode as normal.
  21. Please check that the original settings are correct and that receiver is working correctly in the display menu.
  22. Close the Bossa application.
  23. Remove the USB cable from the PC and flight controller.
  24. Important: After the upload, please remove the propellers (if they aren’t already), switch on the transmitter, plug in the battery, then check that the flight controller and receiver are correctly operating the motors before getting airborne again.

Should you encounter difficulties during the upload process or require technical assistance then please contact us.