USB-C Connection

Connecting peripherals to the USB-C port on the Skynode S

The Skynode S features a multi role USB-C port that allows it to act as a device when connected to a computer, or as a host when peripherals are connected. This is known as a Dual Role Port (DRP).

When connected to another device that supports this capability, e.g., a DTC radio, it can be unclear which device will become the host and which the peripheral. This page outlines the various ways the port can be used, and how to resolve issues with dual-role devices.

Direct Connection

Peripheral devices

USB peripheral devices can be directly connected to the USB-C port on the Skynode S.

Direct connection of See3Cam via USB C-C cable. USB2.0 and USB 3.0 cables work

To connect a USB-A device to the Skynode USB-C port, a variety of USB C to A adapters can be used.

Several USB C to A adapters that have been tested

With the adapter you can connect standard USB A peripherals to the Skynode

Direct connection of IR USB A camera via C to A adapter

Direct connection of USB-C camera via USB 3.0 A to C cable, plugged into a C to A adapter

Dual role devices

For a dual role port (DRP) device, the Skynode must be "forced" to become the USB host.

For example, on a DTC radio, the following setup WILL NOT WORK:

Non-working connection of DTC radio to Skynode S via C to C cable

The Skynode S can be easily forced into host with one of two ways:

1. Using a USB C to A adapter

2. Using a special cable or board that separates the CC lines on the USB connection and adds the required pull-down resistors

USB C to A adapter

Using a standard C to A adapter as outlined above, will force the Skynode to be the USB host.

DTC radio connected with USB A to C cable with a A to C adapter on the Skynode

Special Cable/Board with CC resistor

There are special adapters to signal one side of a USB C connection that it should be the host. For example https://www.adafruit.com/product/6323.This approach has only been validate on USB2.0 connections.

One thing to note: using an adapter like this is directional, and care must be taken to wire it up correctly. If it's plugged in the opposite way, the Skynode will not be damaged. It will simply become the peripheral device.

Example board to fix USB C to C connection on Skynode S

Working connection of a DTC radio using a C-C cable with the fix board

USB Hubs

Connecting a USB hub to the Skynode S via the USB-C port will allow connecting multiple peripherals, and provide significantly more throughput at USB3.0 speeds than the USB2 port.

Using a hub will also side-step the Dual Role Port issue described in the above section.

Below are a few different ways to connect a variety of USB devices to a Skynode. For this example we have chosen

1. USB 2.0 IR camera

2. USB 3.0 Gigabit Ethernet adapter

3. USB 2.0 LTE Modem

A USB 3.0 hub connected to the Skynode via USB-C and a daisy chained USB 3.0 hub connected via USB-A

A different USB 3.0 hub connected to the Skynode via USB-C

A USB 3.0 hub connected to the Skynode via USB-A via a USB A->C adapter