I'm currently doing some experimenting with USB (using node-usb), and I'm printing out each connected device:
Connected Devices:
- [05ac:12ab] iPad 4/Mini1 (Apple, Inc.)
- [05ac:8206] Bluetooth HCI (Apple, Inc.)
- [04f2:0939] undefined (Chicony Electronics Co., Ltd)
- [05ac:8242] Built-in IR Receiver (Apple, Inc.)
- [04f2:0833] undefined (Chicony Electronics Co., Ltd)
- [05ac:8502] Built-in iSight (Apple, Inc.)
- [05ac:8005] OHCI Root Hub Simulation (Apple, Inc.)
- [05ac:8005] OHCI Root Hub Simulation (Apple, Inc.)
- [05ac:8005] OHCI Root Hub Simulation (Apple, Inc.)
- [05ac:8005] OHCI Root Hub Simulation (Apple, Inc.)
The format is - [vendorId:productId] productName (vendorName). The undefined productNames are due to a bug in how I pad the vendorID (I think), they're my mouse and keyboard. The rest are all pretty self-explainitory
But what I want to know is, what's OHCI Root Hub Simulation? I would suspect it's related to EHCI Root Hub Simulation and XHCI Root Hub Simulation, because I could find many articles mentioning them in conjunction (but not defining them). I would also suspect that they are classifications/types/protocols/divisions of USB, as I vaguely remember a broken link to an "OHCI Specification".
Am I correct?
They represent your computer's USB controller, which the computer is communicating with using the UHCI protocol. (That is, it's a USB 2.0 controller.) You see several of them because your computer has multiple USB ports.
If you look carefully at these devices' addresses and port numbers, you'll be able to see which devices are plugged into which ports. If you have any USB hubs, you may want to try hooking them up to see a more "interesting" device tree.