01 — THE PROBLEM
The TV browser is too old for Grafana
The TV is a Samsung with a Tizen browser too old to run Grafana's JavaScript. So the browser never runs Grafana at all.
A Python service renders each dashboard to a JPEG with headless Chromium (Playwright), authenticated with a read-only Grafana token. The TV loads a plain fullscreen page that swaps in the latest frame.
02 — THE CONTROL PANEL
Pick dashboards and rotation from the PC
A second page on localhost picks which dashboards to show, how often to rotate, and has a TV remote that sends key presses to the set. Two tricks made it work: a 125% zoom so the text is readable from the couch, and entering fullscreen by sending the Enter key.
The token and my config are not in the repo.
Source: github.com/tiiow-fedora/tv-dashboard. It is public, so read it, copy it, break it.