How to set a master passcode on my Apple TV

Jelbzz wrote:

Is there a way to set a passcode just to start the tv? For example, if the Apple TV has been asleep for more than 2 hours, when you try to watch something it makes you put in a passcode to wake it up. I know how to restrict content based on age or ratings, but I just want a master passcode to wake it up in the first place. Is there a way to do that?

I'm assuming you're trying to keep one or more members of your household / business / classroom from accessing it? Bummer if there's such a need... Anyway, as @Urquhart1244 said, there's no such feature.

One idea for limiting access to an Apple TV would be to hide the remote control, although iPhone/iPad users with access to the same WiFi/LAN, and the connected TV, could work around this (as could a generic "smart remote").

Another idea, depending on physical access to the setup, might be to isolate the Apple TV on a switched power outlet that only you can turn on from your phone (this idea's problematic if you wish to use the ATV4K as the controlling HomeKit hub :-).

Finally, Apple and their partners have device management tools for IT departments at schools and businesses that include some level of passcode access to modern Apple TV devices (which are pretty common in classrooms and conference rooms).

Perhaps you could put the ATV4K (virtually) into a private "home" via the Home app

Is there a way to do that?

No.