> Complete documentation index: [llms.txt](/llms.txt). Markdown versions of all pages are available by appending `.md` to page URLs.

# USB Interfaces

> Supernova and Pulsar are compound USB devices, exposing both a USB HID interface and a USB CDC interface.

Binho Supernova and Binho Pulsar are **compound USB devices**: a single cable
presents two interfaces to the host at the same time.

{% columns %}
{% column %}
### USB HID

The primary interface, and how the device has always been controlled. Binho
Mission Control and every Binho SDK send commands and receive responses over HID
transfers.

HID is always available and needs no configuration.
{% endcolumn %}

{% column %}
### USB CDC

A virtual COM port, added later. It has grown from a single UART passthrough
bridge into a family of five mutually exclusive operating modes, selected by one
persistent setting.

Which mode is active determines what the COM port does.
{% endcolumn %}
{% endcolumns %}

## Version history

* **Through firmware v4.2.x:** HID only.
* **Firmware v4.3.x:** USB CDC added, as a UART passthrough bridge.
* **Firmware v4.4.0:** the CDC interface gains four further operating modes:
  Terminal, Nova Compatible, RS-485 Bridge, and CAN-FD Bridge.

## In this section

* [USB CDC Operating Modes](/guides/usb-interfaces/usb-cdc-operating-modes/)

The five CDC modes, what each one does, and how to switch between them.

:::note
A page documenting the USB HID command and response format is planned for this
section. In the meantime, the SDKs handle HID framing: see
[Software](/software/).

:::