I use the browser-based Reveal.js framework for all my presentations, so I recently started playing around with the idea of doing presentations via Chromecast, with some success.

Why?

  • Despite HDMI being the /de-rigeur/ standard for video interconnects these days, a good proportion of places I am asked to present at have VGA-only projectors, meaning I was having to carry HDMI-VGA adapter everywhere. Then my new laptop (Dell XPS 13) came with only a USB-C type adapter, so that’s another adapter (USB-C to VGA/HDMI/mDP) to carry. I was looking for some other way that might be a little more modern and adaptable.
  • The average projector has less than 1/4 of the resolution of my laptop, so if I am reduced to mirroring screens, it’s disastrous for the looks of Linux Mint and Cinnamon’s awesome HiDPI scaling :-)
  • I often travel with a Chromecast anyway when I’m travelling, as I use it to stream music or video to the TV in whatever hotel I’m staying in.
  • I thought it would be cool to be able present wirelessly - I can sit with everyone else rather than standing at the front. Sometimes this format just works better, for example in my personal productivity workshops or when live coding.
  • Sometimes you need to send an idea into other people’s brains but you JUST DON’T NEED A PRESENTATION. Really, it can happen. But you might need to, for example, show someone how to use a web app like Trello. So do it. SHOW THE ACTUAL THING. Live teach on the actual thing.

How to do it?

  1. Buy a ChromeCast
  2. Plug it into whatever to are going to present to:
    • Increasingly presentations are done on large TV screens, so you plug into the HDMI input of this. The AV people will be a-hatin’ ya, but hey.
    • With a HDMI-capable projector, just plug your Chromecast right in, as with TV
    • For a VGA-only projector, I found this adapter which has a female HDMI socket for your Chromecast, and a male VGA for the projector. Seems to work, also has a 3.5mm audio jack out for the audio if you need that to end up in a PA system or similar.
    • If it’s a DisplayPort or (holy crap) a DVI-only projector, you are legally entitled to cancel your presentation, still get paid, and tweet offensively about the organisation. Official.
  3. I use this Chrome extension to Cast the contents of any given tab to the Chromecast. A very cool feature is that I don’t necessarily need to be viewing that Casted tab on my machine, I can look at other tabs or other applications, but all the audience will see is the tab I have selected. That’s a significant upgrade on the ‘screen mirroring’