Android device is not connected to USB for debugging (Android studio)

Question

I am trying to debug my application using a real device instead on the emulator. When I try to connect, it gives me the message:

USB device not found<

Answer 1

I have a Samsung Galaxy S4. Although visible from Devices, my phone was not listed as connected from Android Studio. I tried a few things independently, and then together, and found that only a combination of steps fixed the issue, so this is for you if measures listed above or on another site did not work on their own.

1. Enable USB debugging from "Developer Options"
2. Download Kies from Samsung. I believe Samsung US has replaced Kies with a new software called Smart Switch, but this did not resolve anything for me. I found a Samsung UK download of Kies that worked fine.
3. After connecting your phone to your PC via USB, go to your phone notifications and click on USB settings at the top. Switch it to Camera mode.

I repeat, only all 3 of these together fixed the issue, so if some fixes you have tried haven't worked, use these 3 and it could fix the problem for you. Best of luck.