> For the complete documentation index, see [llms.txt](https://spaceandtech-engineerings.gitbook.io/space-and-tech-engineerings-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://spaceandtech-engineerings.gitbook.io/space-and-tech-engineerings-docs/flight-controller/aazmuth/basic-configuration-and-calibration/accelerometer-calibration.md).

# Accelerometer Calibration

This article shows how to perform basic accelerometer calibration (using *Mission Planner*). The accelerometers in the autopilot must be calibrated to correct for their bias offsets in all three axes, as well as any off-axis variations.

{% hint style="danger" %}
**Attention**

Accelerometer calibration is mandatory
{% endhint %}

{% hint style="danger" %}
**Important**

Accelerometer calibration cannot be performed while the vehicle is armed.
{% endhint %}

### Calibration steps

{% hint style="warning" %} <mark style="color:red;">**Warning**</mark>

If the board is mounted in a non-standard orientation (i.e. arrow is not pointing forward) then please ensure the AHRS\_ORIENTATION is properly set before doing the accelerometer calibration.
{% endhint %}

{% hint style="info" %}
Tip

For very large vehicles, this may be done on the bench, after the orientation is set for how it will be mounted in the vehicle and the calibration orientations are done as fit in the vehicle. Then be sure to use the **Calibrate Level** step in the following instructions once mounted.
{% endhint %}

* Under **Setup | Mandatory Hardware**, select **Accel Calibration** from the left-side menu.

<figure><img src="/files/7gdnuB3Y0hju57X86U7T" alt=""><figcaption></figcaption></figure>

Click **Calibrate Accel** to start the full 3-axis calibration.

* *Mission Planner* will prompt you to place the vehicle on each axis during the calibration. Press any key to indicate that the autopilot is in position and then proceed to the next orientation.
* The calibration positions are: level, right side, left side, nose down, nose up, and on its back.

The vehicle must remain still right after you press the key for each step. Staying still is more important than setting the angle perfectly (for example, exactly 90 degrees to horizontal for the left position). Except for the initial **LEVEL** step, each position only needs to be within about 20 degrees of the ideal angle, but the vehicle must not move while you press the key.

* You should calibrate the board mounted in the vehicle if possible.
* However, you may need to calibrate the board before it is mounted if the size/shape of the vehicle makes this difficult.
* The level position is the most important to get right as this will be the attitude that your controller considers level while flying.
* You can recalibrate this Level position using Mission Planner after you have installed the autopilot and are ready to fly. Place the vehicle in its level flying attitude and use the **Calibrate Level** button.<br>

{% hint style="info" %}
Note

This calibration step can only compensate for up to a 10‑degree difference between the original calibration and the vehicle’s final installed orientation. It also only corrects errors in pitch and roll, not yaw.
{% endhint %}

* Proceed through the required positions, using the **Click when Done** button once each position is reached and held still.
* When you have completed the calibration process, Mission Planner will display “Calibration Successful!” as shown below.

<figure><img src="/files/whGrNmL8dOmHJtGncUad" alt=""><figcaption></figcaption></figure>

## Simple Calibration

For very large vehicles, performing a full 3‑axis calibration may not be practical. In these cases, a **Simple Accel Calibration** can be performed with the vehicle held still in a level attitude. This method only calibrates the main accelerometer offsets, not smaller off‑axis errors, so performance is not fully optimized but is often an acceptable compromise.

{% hint style="info" %}
Note

This is **NOT** the same as the **Calibrate Level** function. To use that function, either a full 3-axis or simple calibration must be done first!
{% endhint %}


---

# 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:

```
GET https://spaceandtech-engineerings.gitbook.io/space-and-tech-engineerings-docs/flight-controller/aazmuth/basic-configuration-and-calibration/accelerometer-calibration.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.