8Bitdo Snes Controller turn on/off
To turn on your controller simply press and hold the start button for 3 seconds (or until the blue light comes on top) you will see a blue light on top of the controller start to flash and it will sync up within a few seconds and become a solid blue light, and the menu will start to scroll across, you can just press any button to stop this and your controller is ready to go. If you have two controllers just repeat the process with the second controller and it will now be player two.
Caution: Pressing start button for more than 5 seconds will cause the controller to reset its settings and your controllers will fall out of sync to the console.