The wireless controller enters sleep mode after 5 seconds of idling to save power. To activate it, place your hand 2cm above the wireless controller. The power indicator in the center of the controller will then light up to indicate that it's active again.
Note: For the 2023 version (The function buttons on the controller are in the color of white), users no longer have to activate the wireless controller before use. Please directly tap on the icon to adjust the settings.