Keep screen on forever in Android

To use old Android device as a clock / digital photo frame you probably need this.

This is the adb method. Do the following:

1. 1. Developer options -> TCP debugging (if not plugging in USB cable); otherwise, adb tcpip 5555 with USB cable plugged in, then unplug.
      
   2. Take note of the IP address, then adb connect <ip>
   3. adb shell settings get system screen_off_timeout gives 60000 for timeout of 1 minute
   4. adb shell settings set system screen_off_timeout 2147483647 so it would be on forever (or at least ~24 days at a time)