I've wanted to use simple Chromecast dongles for pumping a Grafana dashboard to a TV for a while now. The challenge has been how to effectively manage the casting source. Chromecasts can't manage any of their own content, they can only be a casting target. I don't want a mobile device sitting in the rack with it's sole purpose being the casting function. Management of that would be difficult. I also want to be able to cast to multiple Chromecasts with the same content or different content.
Google makes this difficult by limiting the signing certificate in the casting protocol. However, some people have worked around it. I've tried two different casting servers and I'm having success with:
https://mrothenbuecher.github.io/Chromecast-Kiosk/
I set up a dedicated VM with pretty light resources, installed Tomcat and then added the Kiosk server. It works really well with one caveat.
The Chromecast dongles will arbitrarily decide if the TV is 720P or 1080P. For most video content this doesn't have a dramatic impact, but when you're trying to display a dense Grafana dashboard it can make all the difference. Unfortunately, this isn't controllable in any way. You have to test it against the TV and hope it works.
I now have a 32" TV in the kitchen which is 1080P (also hard to find at 32") and displaying a pretty dense Grafana dashboard. I'll try to add a picture here later. I think this could be incredibly useful for business monitoring scenarios and is a lot less expensive than putting a PC on a TV.