> For the complete documentation index, see [llms.txt](https://docs.arkelectron.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.arkelectron.com/products/flight-controller/ark-fpv/bootloader-flashing-using-dfu.md).

# Bootloader Flashing Using DFU

DFU can be used to flash or reflash the bootloader with the following steps.

1. With the board unpowered, hold the button next to the USB C port while connecting the USB cable to your PC.
2. Open <https://devanlai.github.io/webdfu/dfu-util/> in Chrome.
3. Select `Connect`, then select `DFU in FS Mode`.

   <figure><img src="/files/drSGVn4Mziblq9N8dASm" alt=""><figcaption><p>DFU Device Selection</p></figcaption></figure>
4. Now select the `@Internal Flash` option.

   <figure><img src="/files/sIr8NPLNYuDNC8I21tqP" alt=""><figcaption><p>Select the @Internal Flash Option</p></figcaption></figure>
5. Now choose the bootloader binary you wish to flash. In this case we are using the default ARK FPV PX4 bootloader which is compatible with PX4 and Ardupilot.

{% file src="/files/WKF1WXXNNsU0AZx6hyrK" %}
ARK FPV PX4 Bootloader Built on Commit [1043aebf5ddd8fd0f6825a27d9a060fa24b616eb](https://github.com/PX4/PX4-Autopilot/commit/1043aebf5ddd8fd0f6825a27d9a060fa24b616eb)
{% endfile %}

<figure><img src="/files/IRUo6Kk9sOF6ZFasgFyX" alt=""><figcaption><p>Firmware Selection</p></figcaption></figure>

6. Select `Download` to flash the firmware.

   <figure><img src="/files/mIysEx8jVZxccTkO9UKK" alt=""><figcaption><p>Start the Firmware Download</p></figcaption></figure>
7. The flash will finish and the firmware will start.


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