Using GraphQL with OpenHAB, some simple examples
Select item from left-hand sidebar
Fecth all the OpenHAB items. You can play with the query to control what data gets returned.
Subscribe to all the events - this will be something of a fire-hose!
Fetch all data from items in a group, and subscribe to updates.
I use this to provide a UI mimic to show electricity import/export from our house displayed as an SVG.
This won’t work directly for you -- you would need a group called “EmonTX” and various values within it, but is just an example of how you might roll your own mimics.