USB Passthrough

Since, Dolphin has the ability to passthrough USB HID devices designed for use with Wii software. And since 5.0-XXXX, Dolphin can passthrough arbitrary USB devices. This gives emulated Wii software full control of a hardware device connected to your PC. This is very useful for devices not currently emulated by Dolphin and games that highly depend on extra hardware.

Linux
Linux support does not require any special drivers. However, a udev rule must be created to allow access to the devices. Note, the Vender ID and Product ID SHOULD be verified from the device itself before creating the rule.

1. Paste the following into /etc/udev/rules.d/52-dolphin.rules (/lib/udev/rules.d/52-dolphin.rules if making a package). Do not forget to replace the XXXX with the appropriate Vendor and Product IDs.

2. Reload udev rules with:

3. Reinsert the accessory.

Before 5.0-XXXX
Download and open Zadig, then:

1. In the "Options" menu in Zadig, make sure "List All Devices" is enabled.

2. Look through the devices for the device to passthrough.

3. On the right column, select "libusbk" then click "Replace Driver". Select "Yes" to modify the system driver.

In the USB branch
Download and install the latest x64 usbdk driver.

macOS
While this can be done in macOS, there is currently no easy to use guide for it. A modified variant of the Native GameCube Adapter for Wii U guide should work, but what needs to be changed is not immediately apparent.

Android
This feature is not supported on Android.

Before 5.0-XXXX
No configuration is required for USB HID passthrough.

In the USB branch
1. Open Dolphin's configuration dialog.

2. Click on the Wii tab.

3. In the "Whitelisted USB passthrough devices", click on the "Add..." button.

4. Select the device you wish to passthrough.