Developing a new Widget and Historic view

Hello everyone!
I am trying to develop a new widget using the Step by step guide (Implementing a UI-Widget :: Open Energy Management System). However I am having some doubts.
As the guide says I copied an already existing module ([FixActivePower]), however I cannot understand where do I define which element will be feeding this New module of information. Example: I created a evcs device in edge (however it only creates random values, which i can see in the terminal in eclipse). Maybe I am just getting confused with the names.

Finally I would like to then plot these values in a chart, to which the guide mentions to use a historic view, however the link to the working example doesnt work.

Is there another guide with more details?

Thank you very much in advance. :smile: