# Sensors

The **Sensors** screen lists most of the sensors that are available to the FC (internal or external). It allows you to start the calibration process for the listed sensors. This step is very important for stable flights. It is required to do the calibration at least once and should be repeated whenever adding new components to the VRC drone or if flight becomes less stable. 

{% hint style="info" %}
Given Phase 2 of VRC will require additional autonomy components and peripherals, it is a good practice to understand the calibration process in detail.
{% endhint %}

Click on **Sensors** in the navigation menu and let's walk through the calibration process for each sensor.

![Default Sensors screen](/files/-MX89a6LA2_XwOw4g4yU)

## Compass

The compass is important for your VRC drone to maintain proper orientation. Click on the **Compass** button and you will be asked to begin the calibration process. This process requires you to position the VRC drone in a number of set orientations and rotate the vehicle about the specified axis.

![Default compass sensor screen before calibration begins.](/files/-MX8FetTQmxERnvft4DG)

Click **Ok** to proceed with the compass calibration. QGC will automatically recognize the orientation of the VRC drone and provide a yellow highlight as shown in the image below.

{% hint style="info" %}
Don't be thrown off by the images of an airplane in the QGC compass calibration process. This still applies to the VRC drone.
{% endhint %}

![Begin the process of rotating the VRC drone around the highlighted axis](/files/-MX8gAyOLBBdIja77oUS)

{% hint style="info" %}
You may find it difficult to rotate the VRC drone with USB connected. It is helpful to have someone keep the cable out of the way while another rotates the drone around its designated axis.
{% endhint %}

Once the orientation is highlighted you can begin rotating the drone until the box is highlighted green. This generally requires one 360 degree rotation around the axis. The image below shows three of the six orientations completed.

![Compass calibration in progress](/files/-MX8ncuO9fY8Q-63zPG4)

After completing the calibration of all axes click **Ok** to return to the sensor setup. It is important to reboot your FC prior to flight, but for now we will move on to calibrating the **Gyroscope**.

![](/files/-MX8gCxUTVTUWfiTPsKh)

## Gyroscope

The gyroscope is an important sensor that will be used to keep your VRC drone level when hovering. Now that the compass calibration is complete you will click on **Gyroscope** to being the process. This will be much easier than compass calibration! Make sure your VRC drone is on a level surface and click **Ok**.

![](/files/-MX8gI0UXdt19M_aIJVL)

After a few seconds, the gyroscope calibration will be complete.

![Successful gyroscope calibration](/files/-MX8gMzwCnQ-oGydY17h)

![Successful gyroscope calibration](/files/-MX8gMzwCnQ-oGydY17h)

## Accelerometer

The accelerometer works in conjunction with the gyroscope to keep your VRC drone level along each axis. Click on **Accelerometer** and then **Ok** to begin the calibration process.

This process is fairly similar to compass calibration but does not require you to rotate the drone around each axis. You simply need to hold the drone level in each orientation. QGC will detect the orientation, which is denoted by the yellow border.

![Accelerometer calibration in progress](/files/-MXIsr56AzqSqtVaXuKm)

Hold your VRC drone steady in each orientation for approximately 5-10 seconds. As you complete each axis the border will turn green in QGC.

![Accelerometer calibration complete](/files/-MXItTAavtma6jk0wm4z)

## Level Horizon

Level horizon is a simple calibration to make sure your FC understands the default level position when powered on. Click on the **Level Horizon** button and then **Ok**. This process will take more than a couple of seconds to complete.

![Level Horizon calibration complete](/files/-MXIu5jGRbAmFaHveKzu)

## Orientations

Given we have mounted the FC in its default orientation (facing up and forward) this calibration is unnecessary.

Nice work! You have calibrated the necessary sensors for your VRC drone to be able to know its orientation and keep level during flight. The following Summary screen shows the successful steps completed in green. Now we will move onto setting up the **Radio** (aka Transmitter).

![Summary screen showing all sensors calibrated and ready for flight](/files/-MX8mm2-BDdnPtRW4Lxz)


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