TypeError: 'NoneType' object is not subscriptable

[cosmindful]

Replicate Issue

• do not connect the Waterlinked Box or pull Locator outside water
• start the ROS Master
• start Waterlinked ROS Driver

Description or error

When the connection to the locator is interrupted or not properly established, that the values returned by the HTTP API are null. These are not correctly parsed by the ROS Driver, but as soon as the first null response is received, the error in the title is thrown.

Effect

ROS Driver crashes when the Waterlinked connection is not working properly. This can stall data collection and impede autonomous naviagation because one has to manually check the the ROS node is running and hasn't crashed.