First of all, I have not returned to using the Chromecast for my Grafana visualization. I didn’t elaborate on this, but my previous post was driven by a change to Grafana visualization that effectively broke the ChromeCast Kiosk server I was using. The recommended solution was to use a proxy for displaying the iFrame, or something. I wasn’t keen on setting up another server instance (not that big a deal) just for the purpose of running the proxy. Yes, I know I could have set that up on the same kiosk server.
I quickly implemented the RPi Zero W I referenced in my previous post, just to get something up and running. It works ok in kiosk mode. There are a couple of issues that are relatively minor. It’s only remotely managed via SSH. The previous Chromecast was managed from the server. Very simple to make adjustments with that. Any adjustments to the RPi must be made via SSH. I’m comfortable with that, but I don’t access the RPi enough for it not to be a little relearning every time.
The RPi will not dynamically update a Grafana dashboard. I’m sure I could script it to reload on a certain interval. This was also a benefit of the ChromeCast server. Well, sort of a benefit. The CC Server could have a refresh interval which would reload the page. You could also manually force the refresh. My only way to do that with the RPi is to pull the power, or SSH in and reboot it. Or figure out how to script it. Which brings me to the big negative to the RPi…
This thing is slow. So….slow…. Doesn’t really matter when the dashboard is up and running. It will happily do the Grafana 1 minute refresh without issue. A reboot takes something like 10 minutes before the dashboard is fully drawn. Even the SSH session is pokey. Slow…. The Zero is still running the same CPU as the RPi 1, just a little overclocked. You’d think they could move to the RPi 2/3 CPU at this point and still keep the price down.
Which brings me to the reason I’m sticking with this as my solution. The Zero W is $10. The current generation CC is going for at least $30 and seems to rarely be on sale for less. A third of the cost sure buys a lot of patience with the other issues I have. The Zero W works fine with USB power from the TV, and can usually be hidden behind the TV with some double-sided tape. No case needed. Ok, you need to spend a few bucks on a SD card.
Could be a nice solution for a NOC full of TVs!