# can't get rviz working

Source: https://forum.modalai.com/topic/1210/can-t-get-rviz-working
Category: Flight Core and Legacy VOXL (https://forum.modalai.com/category/9/flight-core-and-legacy-voxl)
Tags: voxl-cam
Posted: 2022-08-16 19:03:36 UTC by fjksalf
Replies: 1 · Views: 1173

## fjksalf · 2022-08-16 19:03:36 UTC

Have been following the [voxl cam setup guide](https://docs.modalai.com/voxl-cam-user-guide-core) but we keep getting the unable to communicate with master error.

What are the voxl cam's ros_master_uri and ros_ip supposed to be? what are they supposed to be on the host pc?

The goal is to get rviz running but we keep getting the "could not contact ros master at..." error.

is the command we need to use roscore on the voxl camera? the guide says ```roslaunch voxl_mpa_to_ros voxl_mpa_to_ros.launch``` but we get a different output than what the guide says.

rviz on pc? we found ```rosrun rviz rviz ```

## Reply by nickyblanch · 2023-11-05 00:08:25 UTC

@fjksalf If the IP address of the VOXL is 192.168.1.1 then you need to execute export ROS_MASTER_URI=http://192.168.1.1:11311 on the Ubuntu system and then run rviz from the same terminal.