Apple TV, by AirPlay
An Apple TV can mirror a Mac or an iPad over AirPlay. Good if you already have one in the room; as with casting, whatever is mirroring has to stay awake and stay put for the whole evening.
What you need
- An Apple TV connected to the screen and to the internet
- A Mac or iPad on the same wi-fi network
- Mains power for whichever device is mirroring
Setting it up
Put both devices on the same network
AirPlay needs them on the same wi-fi. A venue with separate staff and guest networks will stop the Apple TV appearing as an option at all.
Open the wall link, then start mirroring
Open the link ending in /wall, then use Screen Mirroring from the Control Centre on a Mac or an iPad and pick the Apple TV.
Go full screen
Control-Command-F in Safari or Chrome on a Mac. On an iPad, the browser fills the screen already.
Stop the mirroring device sleeping
Set the display to never sleep while on power. A Mac that sleeps takes the wall down with it.
If something is wrong
The Apple TV is not offered as a mirroring target
Different networks, almost always. Check both, and confirm AirPlay is switched on in the Apple TV's own settings.
Mirroring keeps dropping
A crowded venue network is the usual cause. If it happens more than once, move to an HDMI cable — the room is only going to get busier as the evening goes on.