Google Stadia Controller[]
Firmwares[]
The controller has 2 firmwares available, Wi-Fi mode (internally called 'gotham') for playing games on Stadia, and Bluetooth (internally called 'bruce'). After converting to Bluetooth, you will be unable to use wired audio devices while connected via Bluetooth, and vibration will not function on Windows.[1]
Despite Google's official updater tool warning you that you will be unable to switch back to Wi-Fi firmware, this has already been proven to be false.[2]
Tandem Mode[]
By plugging another controller into the USB-C port on the Stadia Controller, the inputs from the external controller will be transferred through the Stadia controller to the device it is paired to. A list of supported controllers can be found here.[3]