Unveiling USBHUB3+ Enumeration Speed: How to Determine Your Connected Devices' Speed

Learn how to determine the enumeration speed of devices connected to USBHUB3+ and whether they're operating at high or super speeds.

Each port on USBHub3+ can operate in High Speed or Super Speed modes. There are three ways to view the speed of a connected port

1. Front panel LED

2. HubTool virtual LED

3. Brainstem API

Connecting a USB 2.0 device to port 0, you should see a yellow LED on the hub front panel, and a corresponding yellow box in HubTool indicating a high-speed connection.

Port speed on a USBHUB3+ can also be queried using Python. We'll be working in an interactive Python console to be able to work line-by-line.  

If you haven’t already, install the Brainstem package (See the Quickstart Guide for more detail)

>>> import brainstem

Create an instance of the USBHub3p called "hub"

>>> hub = brainstem.stem.USBHub3p()

Discover and connect to the hub

>>> hub.discoverAndConnect(brainstem.link.Spec.USB) 0

A return value of 0 means no error.  

>>> hub.usb.getDownstreamDataSpeed(0).value
1

High Speed connection:

The speed description refers to which data lines are active.  An iPhone connected via lightning at up to 480 Mb/s and a USB mouse at up to 1.5 Mb/s would both appear as High-Speed devices on the hub and HubTool LEDs and return a "1" because they are using the USB 2.0 High-Speed data lines.

What else could you do with USBHub3+?

• Independently control VBus and data for each port
  • Turn on and off VBus
  • Enable and disable data connections:
• Power Measurements
  • Measure current and voltage on each port
  • Monitor input power and system power
• Switch ports between Charging Downstream Port (CDP) and Standard Downstream Port (SDP) (up to 500 mA)
• View the enumeration speed of a connected device
• Switch upstream hosts
  • Automatically 
  • Programatically
• Add more ports by daisy chaining hubs
• Other uses of the USBHub3+