thomasvon2021 / pikvm-usb-splitter

USB/PWR Splitter for pikvm

USB/PWR Splitter

1. Introduction

The adaptor allows the Raspberry Pi 4 to be used with a Pi USB-C power supply while allowing access to USB OTG data over a separate USB-C connection.

USB-C (RPI4) <> USB-C (USB) and USB-C (PWR)

USB-C(RPI4)	USB Type-C(USB)	USB Type-C(PWR)
5V		5V
D-	D-
D+	D+
CC1 10k to 5V	CC1 5.1k to GND	CC1 5.1k to GND
CC2 10k to 5V	CC2 5.1k to GND	CC2 5.1k to GND
GND	GND	GND

To use the adaptor with the Raspberry Pi 4 you need.

• USB-C to USB-C cable[1] between Pi4 and the adaptor board
• USB-C to USB-C or Type-A between adaptor board and PC
• Power[2] via Official Raspberry Pi USB Type-C Power Supply.

[1] 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.

[2] PLEASE NOTE With the Pu/Pd resistors on this board it can only be used with 5V supply to power a 5V device.

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.

2.Mechanical Diagram

3.Test video

USB splitter https://www.youtube.com/watch?v=4Od5MjBHbhY

pikvm-usb-splitter's Issues

CC1 and CC2 required for OTG?

Are CC1 and CC2 (and thus their resistors) even required? Isn't it that only D+ and D- would be required for OTG functionality?