> 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/gps/ark-dan-gps/ardupilot-instructions.md).

# Ardupilot Instructions

### Firmware Setup <a href="#firmware-setup" id="firmware-setup"></a>

The IIS2MDC magnetometer driver was added in January 2025 and requires Ardupilot version 4.6 or newer.

Use the [Ardupilot Custom Firmware Builder](https://custom.ardupilot.org/) to compile firmware for your autopilot with the IIS2MDC driver. Select `IIS2MDC Compasses` under `Compass` for your board.

<figure><img src="/files/91weU0TuxA4QE6OjBOAZ" alt=""><figcaption></figcaption></figure>

This PR can be backported into previous releases of Ardupilot.

<https://github.com/ArduPilot/ardupilot/pull/28602>

Configure [SERIALX ](https://ardupilot.org/copter/docs/parameters.html#serial-parameters)to GPS on the port the GPS is connected to. On the ARK FPV GPS port, this is set by default and is plug and play.

Ensure [COMPASS\_EXTERNAL ](https://ardupilot.org/copter/docs/parameters.html#compass-external-compass-is-attached-via-an-external-cable)is set to 1 to auto detect the magnetometer on I2C.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## 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, and the optional `goal` query parameter:

```
GET https://docs.arkelectron.com/products/gps/ark-dan-gps/ardupilot-instructions.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

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.