I was given an old Apple TV
Apple TV (3rd generation)
Identify your Apple TV model - Apple Support
Find your Apple TV model number - Apple Support
Does it have model number A1427 or A1469 on it?
After resetting it, even when I go to settings and enter my Apple ID, it won’t connect or show up on my MAC or IPhone as an option to add as a device.
AirPlay and Home Sharing are opposites in a way, in that AirPlay is controlled on the sending device, and Home Sharing is controlled on the receiving device.
Use AirPlay to stream video or mirror the screen of your iPhone or iPad - Apple Support
Stream audio and video from your Mac with AirPlay - Apple Support
Use AirPlay Screen Mirroring to stream what’s on your Mac to an HDTV - Apple Support
vs.
Use Home Sharing to share media from a computer to other devices - Apple Support
… tried connecting the ATV to my computer (HDMI-HDMI)
That will never work. The Apple TV box takes input from the network and outputs over HDMI to the TV screen. Computers may have HDMI-out, but generally not HDMI-in.
I’ve read several threads about iTunes, but I can’t even create an account as I have the Sonoma OS on my computer.
macOS Catalina 10.15 and later changed from the all-in-one iTunes application to the separate component apps for TV and Music, etc.
For in-app AirPlay and system wide AirPlay screen mirroring, no special settings are needed on the Mac. It is always available, when connected to a home network.
For Home Sharing, activate that function in System Settings﹥General﹥Sharing﹥☑ Media Sharing﹥ⓘ﹥☑ Home Sharing﹥[set Library name, set Apple ID account for Home Sharing].
How can I get this device to connect to my HomeKit and be useable for screen mirroring/air play?
- HomeKit is unrelated to this. HomeKit is about smart-home appliances, and Apple TV (3rd generation) is not a hub for that (too old).
- You will need to register/activate the Apple TV box with an Apple ID account, else AirPlay receiving will not be active. This would be automatic through initial setup. Else sign in with your Apple ID for the Store (iCloud services are not relevant for this).
- The Apple TV box has an On|Off switch for AirPlay receiving in Settings﹥AirPlay﹥. Verify that it is set to On.
- The sending device and the receiving device will need to be connected to the same home network. For Wi-Fi, that means the exact same SSID network name (Apple TV box: Settings﹥Network﹥).
