Head on over to settings on your device and scroll down to where it says "About phone" and click that.
tap on "software information"
Find where it says "build number" and keep tapping on it until a message tells you that developer mode is turned on.
Now that developer mode is on, you can now find the developer settings at the bottom of the settings app.
click "developer options" underneath where it says "About phone"
Near the top, there should be a setting that says "Stay awake". Turn this on. This allows your phone screen to stay on while charging (and charging only).
