@bminer1 - I’m glad your FiL likes your mirror! To answer his question, the answer is generally “Any location with a web API is easy. Most other data sources are possible *.”
I’ve been developing systems for more years than I care to admit. I would guess that he has an employee/coworker who maintains a spreadsheet with metrics for his various processes. Spreadsheets are simple and easy to use, so they end up doing a lot of lifting in any business. The spreadsheet probably performs both data storage and calculation roles and they’ve probably been using it for years.
I wonder… there’s got to be a simple tool out there that will use a spreadsheet as a data source and expose an API to query the spreadsheet. You could then use the existing modules (MMM-Rest, for example) to query that API.
*Sometimes I am too much of a literalist. There are certain sources of data that are too large for the Pi to handle with its limited memory and processor. You will not be able to display a ray tracing rendering process, for example, as there is too much data for the Pi to keep up.
