> For the complete documentation index, see [llms.txt](https://docs.ceruleansonar.com/c/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.ceruleansonar.com/c/dvl-75/using-mavlink-and-blueos-for-position-hold-on-a-bluerov2/ardupilot-parameters.md).

# ArduPilot Parameters

If your ArduPilot software is not set up for position hold, you will need to set up some parameters.

Log into BlueOS by connecting to the ROV and browsing to <http://blueos.local> <http://192.168.2.2> -- this is the default address, if you have changed the ROV's IP address you will need to substitute it. You will see the following screen:

<figure><img src="/files/d5OydiZPSKsRUiHNu16m" alt=""><figcaption><p>BlueOS landing page</p></figcaption></figure>

Click the Autopilot Parameters tile. You should land on this page:

<figure><img src="/files/GbC97eFpd6CvSAtgCGo1" alt=""><figcaption><p>Autopilot Parameters Landing Page</p></figcaption></figure>

Using the search and editing tools, change the parameter listed below to the given values. Don't forget to save the parameters after you change them.

Required Changes:

* EK3\_ENABLE: Enabled
* EK2\_ENABLE: Disabled
* AHRS\_EKF\_TYPE: Enable EKF3
* VISO\_TYPE: MAVLink
* GPS\_TYPE:  AUTO
* EK3\_SRC1\_POSXY: ExternalNav
* EK3\_SRC1\_VELXY: ExternalNav
* EK3\_SRC1\_POSZ: Baro
* RNGFND1\_TYPE: MAVLink
* RNGFND1\_MAX\_CM: 5000

  &#x20;

Suggested Starting PIDs:

* PSC\_POSXY\_P 0.6
* PSC\_POSZ\_P  1.0
* PSC\_VELXY\_D 0.2
* PSC\_VELXY\_I 0.02
* PSC\_VELXY\_P 4.0
* PSC\_VELZ\_P  5.0
* ACRO\_YAW\_P  4
* ATC\_RAT\_YAW\_FLTE 5