The adaptor allows the Raspberry Pi 4 to be used with a Pi USB-C power supply (or DC barrel jack) whilst allowing access to USB OTG data over a separate USB-C connection.
USB Type-C (DATA POWER) <> USB Type-C (USB2 DATA) and USB Type-C (POWER) OR Barrel jack (POWER).
|USB Type-C (DATA/POWER)||USB Type-C (DATA)||USB Type-C (POWER)||Barrel Jack|
|CC1 5.1k to GND|
|CC2 5.1k to GND|
The barrel jack accepts 5.5 mm plugs (2.1/2.5 pin) supplying 5V.
To use the adaptor with the Raspberry Pi 4 you need.
- USB-C to USB-C cable between Pi4 and the adaptor board (DATA/POWER)
- USB-C to USB Type-C or Type-A between adaptor board and PC (USB2 DATA)
- Power via either Official Raspberry Pi USB Type-C Power Supply or Barrel jack (5v 2.4 Amp or higher PSU).
 Whilst USB-C cables are generally designed for higher current I still advise using short power cable to the Pi where possible to reduce voltage drop.
 PLEASE NOTE When using a "smart" power supply/cable the connections carrying power (POWER and DATA/POWER) will only work in one orientation (only one CC pin is connected through the cable). If your Pi isn't powering up please rotate either the POWER cable or DATA/POWER cable 180 degrees and re-plug (NOT both).
Using a Cluster HAT node image (p1/p2/p3/p4) you can plug the USB DATA into a computer (Raspberry Pi, Win10, etc.) and access the system via either USB Gadget Ethernet or Serial Console. Can also be used with Pi-KVM.
An adaptor of this kind does not fall within the USB specification. It's designed for use with the official Raspberry Pi USB-C power supply and raspberry pi, use with other power supplies/chargers and devices may cause issues/damage.