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Urg Node Installation
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We use the Hokuyo UTM-30LX-EW. 

In order to use this external sensor, we need to install a driver that will communicate with and control the lidar. The driver we use
is the urg node.

.. tabs::
    .. group-tab:: Linux
        
        .. code-block:: bash

            sudo apt-get install ros-foxy-urg-node
            cd ~/urg_node
            colcon build

In order to communicate with the lidar and receive data over its ethernet cable plugged into your laptop, you need to be on the same subnet as the laser. 
The lidar's default ip is :code:`192.168.0.10`, so you might need to change your ip, for something on the same subnet.

.. tabs::
    .. group-tab:: Linux

        * Go into the network settings. 
        * Settings of the wired connection. 
        * under IPv4, change the IPv4 method from automatic to Manual and under Addresses, set the values:

        .. code-block:: bash

            Address : 192.168.0.15
            Netmask : 255.255.255.0
            Gateway : 192.168.0.1

        * Under eth0 (or maybe something like enpxxxxx), your IP should be 192.168.0.15. You should now be able to ping the ust-20lx at its address (by default 192.168.0.10)

        .. code-block:: bash
            
            ping 192.168.0.10

        * If you don't receive any answer, you might have a connection problem or the IP of your laser might have been change, either find it and go on the same subnet or reset it.

Once you can ping the laser, launch the urg_node_driver using the directions in the Launch section.