# Navigator questions

**URL:** <https://discuss.bluerobotics.com/t/navigator-questions/12377>\
**Category:** Flight Controllers\
**Tags:** ardusub, pymavlink, navigator\
**Created:** [June 21, 2022, 10:00pm UTC](https://discuss.bluerobotics.com/t/navigator-questions/12377 "2022-06-21T22:00:40Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![rattasak](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@rattasak](https://discuss.bluerobotics.com/u/rattasak)\
**Post date:** [June 21, 2022, 10:00pm UTC](https://discuss.bluerobotics.com/t/navigator-questions/12377/1 "2022-06-21T22:00:41Z")

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Hi,

We’re currently using Pixhawks for the flight controller in some robotics platforms we develop, and I had a few questions about the Navigator flight controller I was hoping someone can help me with:

- I assume that the Pi4 + Navigator board work in tandem to replace the Pixhawk. Is Ardupilot/Ardusub run on the Pi4 running BlueOS?
- Is it possible to use Pymavlink to send commands and receive data from the Pi4+Navigator board? With a Pixhawk, we currently do this by communicating with the Pixhawk’s device file when it’s attached to a Linux companion computer. If we wanted to run our vehicle control software on a computer separate from the Pi4+Navigator (it would only be doing the flight controller processing), what would be a good way handle Pymavlink comms between the Pi4+Navigator and the vehicle control computer?

Thanks,  
-rattasak

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**Author:** ![EliotBR](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/eliotbr/32/6937_2.png) [@EliotBR](https://discuss.bluerobotics.com/u/EliotBR)\
**Post date:** [June 28, 2022, 4:17am UTC](https://discuss.bluerobotics.com/t/navigator-questions/12377/2 "2022-06-28T04:17:54Z")

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Hi @rattasak, sorry for the delay on responding to this.

> [@rattasak](#):
>
> - I assume that the Pi4 + Navigator board work in tandem to replace the Pixhawk. Is Ardupilot/Ardusub run on the Pi4 running BlueOS?

That’s correct, and yes, the Navigator + RPi4 combo operates as a linux-based flight controller, where the Navigator is essentially an advanced I/O board that allows the ArduPilot firmware running on the RPi4 to interact with the physical world (via its sensors and actuators).

> [@rattasak](#):
>
> Is it possible to use Pymavlink to send commands and receive data from the Pi4+Navigator board?

Yes, you can [set up and configure MAVLink endpoints in BlueOS](https://docs.bluerobotics.com/ardusub-zola/software/onboard/BlueOS-1.0/advanced-usage/#endpoints), which can then be connected to and communicated with via Pymavlink. It’s also possible to use the [mavlink2rest](https://github.com/patrickelectric/mavlink2rest) connection (TCP port 6040) if you’d prefer a REST-based interface.

> [@rattasak](#):
>
> If we wanted to run our vehicle control software on a computer separate from the Pi4+Navigator (it would only be doing the flight controller processing), what would be a good way handle Pymavlink comms between the Pi4+Navigator and the vehicle control computer?

Presumably ArduSub would be running the low level control, and your separate control computer would be sending higher level commands? A MAVLink endpoint connection for that should be fine - a UDP client endpoint is likely the most stable 🙂