# Autopilot Connections

There are two primary communication channels between the VOXL and the Flight Controller: Serial and USB.

<table><thead><tr><th width="138">Type</th><th width="189">VOXL</th><th>Flight Controller</th></tr></thead><tbody><tr><td>USB</td><td>USB</td><td>USB</td></tr><tr><td>Serial</td><td>UART13</td><td>Telem2</td></tr></tbody></table>

{% hint style="info" %}
We recommend running MAVLink on USB and XRCE-DDS on Serial.
{% endhint %}

## Flight Controller USB Enable

The flight controller USB will not start until GPIO\_154\_VBUS\_SENSE from the VOXL is driven high. If this signal is high when the flight controller is reset, it will wait in the bootloader for 5 seconds before booting. If it is low, the flight controller will boot immediately.

## Flight Controller Reset

The flight controller can be hard reset using the reset signal connected to VOXL pin GPIO\_153\_FMU\_RST\_REQ. The VOXL cannot reset the flight controller while it is armed. The reset signal is gated by the nARMED signal from the flight controller.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.arkelectron.com/products/flight-controller/ark-voxl2-rtk-pab-carrier/autopilot-connections.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.