# Flight Controller Firmware

In Phase 2, you'll need to update the firmware of your NXP flight controller, with a custom version of PX4 in order for your drone to properly work with the April Tags.

First, download **the `nxp_fmuk66-v3_default.<version>.px4` file** from the latest GitHub release to your Windows computer: <https://github.com/bellflight/VRC-2021-Phase-II/releases/latest>

Now, connect the NXP flight controller to your Windows computer with the included Micro USB cable. Make sure you orient the cable correctly, it's upside down of what you might expect.

![](/files/-Mj75K511234OY9VN6Gl)

Now, open QGroundControl, click on the "Q" in the top-left, then "Vehicle Setup" and finally "Firmware".

![](/files/-Mj74HfpwLnEcK2jDz5n)

![](/files/-Mj74NHDIOkelht6bSaS)

Once QGroundControl recognizes the flight controller, select "Advanced Settings", then "Custom firmware file..."

![](/files/-Mj75oxQcjj2w2uP-aZz)

Then click "Ok" and select the firmware file you downloaded. Now, just let QGroundControl do it's thing.

![](/files/-Mj767l_VsVnPMkNJb2P)

When it it's finished, you'll see the message "Upgrade complete" and the window will close itself.

![](/files/-Mj76M98KavTopPdDFCY)


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