# Transport

USB-level topology and the internal serial bus that the wheelbase hub multiplexes.

| File | Topic |
|------|-------|
| [`usb-topology.md`](usb-topology.md) | USB composite device (VID `0x346E` PID `0x0006`), interfaces, endpoints, MI_00 serial vs MI_02 HID split |
| [`internal-bus.md`](internal-bus.md) | `monitor.json` device tree, bus IDs vs serial protocol device IDs, per-base wiring |
